Multi Vitamin Chewable

Multi Vitamin Chewable Uses, Dosage, Side Effects, Food Interaction and all others data.

vitamin C, the water-soluble vitamin, is readily absorbed from the gastrointestinal tract and is widely distributed in the body tissues. It is believed to be involved in biological oxidations and reductions used in cellular respiration. It is essential for the synthesis of collagen and intracellular material. Vitamin C deficiency develops when the dietary intake is inadequate and when increased demand is not fulfilled. Deficiency leads to the development of well defined syndrome known as scurvy, which is characterized by capillary fragility, bleeding (especially from small blood vessels and the gums), anaemia, cartilage and bone lesions and slow healing of wounds.

Ascorbic Acid (vitamin C) is a water-soluble vitamin indicated for the prevention and treatment of scurvy, as ascorbic acid deficiency results in scurvy. Collagenous structures are primarily affected, and lesions develop in bones and blood vessels. Administration of ascorbic acid completely reverses the symptoms of ascorbic acid deficiency.

Vitamin B12 (cyanocobalamin) is required for the maintenance of normal erthropoiesis, nucleprotein and myelin synthesis, cell reproduction and normal growth; Coenzyme; metabolic functions include protein synthesis and carbohydrate metabolism. Plays role in cell replication and hematopoiesis.

General effects

Cyanocobalamin corrects vitamin B12 deficiency and improves the symptoms and laboratory abnormalities associated with pernicious anemia (megaloblastic indices, gastrointestinal lesions, and neurologic damage). This drug aids in growth, cell reproduction, hematopoiesis, nucleoprotein, and myelin synthesis. It also plays an important role in fat metabolism, carbohydrate metabolism, as well as protein synthesis. Cells that undergo rapid division (for example, epithelial cells, bone marrow, and myeloid cells) have a high demand for vitamin B12 .

Parenteral cyanocobalamin effects

Having a chemical formula of F−, fluoride ion is the simplest inorganic, monatomic anion of fluorine with basic properties. It is considered a trace element. Fluoride ions are found in various minerals but are only present in trace amounts in water. Its various salt forms and minerals play numerous roles as chemical reagents, industrial chemicals, and commercial products. It also plays an essential physiological role, such as enhancing the resistance profile and strength of the surface tooth enamel.

Folic acid is essential for the production of certain coenzymes in many metabolic systems such as purine and pyrimidine synthesis. It is also essential in the synthesis and maintenance of nucleoprotein in erythropoesis. It also promotes WBC and platelet production in folate-deficiency anaemia.

Folic acid is a water-soluble B-complex vitamin found in foods such as liver, kidney, yeast, and leafy, green vegetables. Also known as folate or Vitamin B9, folic acid is an essential cofactor for enzymes involved in DNA and RNA synthesis. More specifically, folic acid is required by the body for the synthesis of purines, pyrimidines, and methionine before incorporation into DNA or protein. Folic acid is the precursor of tetrahydrofolic acid, which is involved as a cofactor for transformylation reactions in the biosynthesis of purines and thymidylates of nucleic acids. Impairment of thymidylate synthesis in patients with folic acid deficiency is thought to account for the defective deoxyribonucleic acid (DNA) synthesis that leads to megaloblast formation and megaloblastic and macrocytic anemias. Folic acid is particularly important during phases of rapid cell division, such as infancy, pregnancy, and erythropoiesis, and plays a protective factor in the development of cancer. As humans are unable to synthesize folic acid endogenously, diet and supplementation is necessary to prevent deficiencies. In order to function properly within the body, folic acid must first be reduced by the enzyme dihydrofolate reductase (DHFR) into the cofactors dihydrofolate (DHF) and tetrahydrofolate (THF). This important pathway, which is required for de novo synthesis of nucleic acids and amino acids, is disrupted by anti-metabolite therapies such as Methotrexate as they function as DHFR inhibitors to prevent DNA synthesis in rapidly dividing cells, and therefore prevent the formation of DHF and THF.

In general, folate serum levels below 5 ng/mL indicate folate deficiency, and levels below 2 ng/mL usually result in megaloblastic anemia.

Niacin is a preparation of Nicotinic acid. It is proven effective at lowering VLDL, LDL, total cholesterol and triglyceride levels while raising HDL levels. So Niacin has been prescriped for the treatment of cardiovascular disease particularly the hyperlipidemias.

Niacin is a B vitamin used to treat vitamin deficiencies as well as hyperlipidemia, dyslipidemia, hypertriglyceridemia, and to reduce the risk of myocardial infarctions. Niacin acts to decrease levels of very low density lipoproteins and low density lipoproteins, while increasing levels of high density lipoproteins. Niacin has a wide therapeutic window with usual oral doses between 500mg and 2000mg. Patients with diabetes, renal failure, uncontrolled hypothyroidism, and elderly patients taking niacin with simvastatin or lovastatin are at increased risk of myopathy and rhabdomyolysis.

Pyridoxine is a water-soluble vitamin which functions in the metabolism of carbohydrates, proteins and fats. It is essential in Hb formation and GABA synthesis within the CNS. It also aids in the release of glycogen stored in the liver and muscles.

Vitamin B6 (pyridoxine) is a water-soluble vitamin used in the prophylaxis and treatment of vitamin B6 deficiency and peripheral neuropathy in those receiving isoniazid (isonicotinic acid hydrazide, INH). Vitamin B6 has been found to lower systolic and diastolic blood pressure in a small group of subjects with essential hypertension. Hypertension is another risk factor for atherosclerosis and coronary heart disease. Another study showed pyridoxine hydrochloride to inhibit ADP- or epinephrine-induced platelet aggregation and to lower total cholesterol levels and increase HDL-cholesterol levels, again in a small group of subjects. Vitamin B6, in the form of pyridoxal 5'-phosphate, was found to protect vascular endothelial cells in culture from injury by activated platelets. Endothelial injury and dysfunction are critical initiating events in the pathogenesis of atherosclerosis. Human studies have demonstrated that vitamin B6 deficiency affects cellular and humoral responses of the immune system. Vitamin B6 deficiency results in altered lymphocyte differentiation and maturation, reduced delayed-type hypersensitivity (DTH) responses, impaired antibody production, decreased lymphocyte proliferation and decreased interleukin (IL)-2 production, among other immunologic activities.

Riboflavin is a B vitamin. It can be found in certain foods such as milk, meat, eggs, nuts, enriched flour, and green vegetables. Riboflavin is frequently used in combination with other B vitamins in vitamin B complex products. Vitamin B complex generally includes vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin/niacinamide), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B12 (cyanocobalamin), and folic acid. However, some products do not contain all of these ingredients and some may include others, such as biotin, para-aminobenzoic acid (PABA), choline bitartrate, and inositol.

Riboflavin is used for preventing low levels of riboflavin (riboflavin deficiency), cervical cancer, and migraine headaches. It is also used for treating riboflavin deficiency, acne, muscle cramps, burning feet syndrome, carpal tunnel syndrome, and blood disorders such as congenital methemoglobinemia and red blood cell aplasia. Some people use riboflavin for eye conditions including eye fatigue, cataracts, and glaucoma.

Other uses include increasing energy levels; boosting immune system function; maintaining healthy hair, skin, mucous membranes, and nails; slowing aging; boosting athletic performance; promoting healthy reproductive function; canker sores; memory loss, including Alzheimer's disease; ulcers; burns; alcoholism; liver disease; sickle cell anemia; and treating lactic acidosis brought on by treatment with a class of AIDS medications called NRTI drugs.

Riboflavin or vitamin B2 is an easily absorbed, water-soluble micronutrient with a key role in maintaining human health. Like the other B vitamins, it supports energy production by aiding in the metabolising of fats, carbohydrates, and proteins. Vitamin B2 is also required for red blood cell formation and respiration, antibody production, and for regulating human growth and reproduction. It is essential for healthy skin, nails, hair growth and general good health, including regulating thyroid activity. Riboflavin also helps in the prevention or treatment of many types of eye disorders, including some cases of cataracts.

Thiamine, in the form of thiamine pyrophosphate, is the coenzyme for decarboxylation of α-ketoglutaric acid. Thiamine deficiency affects the peripheral nervous system, the gastrointestinal tract, and the cardiovascular system. This vitamin is necessary for the optimal growth of infants and children. Thiamine is not stored in the body, and is regularly lost from tissues during short periods of deficiency. In order to maintain normal health, an adequate amount of thiamine is required every day. Deficiency of thiamine leads to fatigue, anorexia, gastrointestinal disturbance, tachycardia, irritability and neurological symptoms. Beriberi, a disease due to vitamin B1 deficiency, is common in alcoholics, in pregnant women receiving an inadequate diet, and in people with malabsorption syndrome, prolonged diarrhoea and hepatic disease.

Thiamine is well absorbed from the gastrointestinal tract and widely distributed throughout the body. Thiamine is rapidly absorbed from the upper small intestine. Thiamine is not stored in the body to any appreciable extent. Excess ingested thiamine appears in urine as intact thiamine or as pyrimidine, which arises from degradation of the thiamine molecule. The plasma half life of thiamine is 24 hours.

Thiamine is a vitamin with antioxidant, erythropoietic, cognition-and mood-modulatory, antiatherosclerotic, putative ergogenic, and detoxification activities. Thiamine has been found to protect against lead-induced lipid peroxidation in rat liver and kidney. Thiamine deficiency results in selective neuronal death in animal models. The neuronal death is associated with increased free radical production, suggesting that oxidative stress may play an important early role in brain damage associated with thiamine deficiency. Thiamine plays a key role in intracellular glucose metabolism and it is thought that thiamine inhibits the effect of glucose and insulin on arterial smooth muscle cell proliferation. Inhibition of endothelial cell proliferation may also promote atherosclerosis. Endothelial cells in culture have been found to have a decreased proliferative rate and delayed migration in response to hyperglycemic conditions. Thiamine has been shown to inhibit this effect of glucose on endothelial cells.

Vitamin A plays an essential role in the function of retina and is essential for growh and differentiation of epithelial tissue.

Vitamin A is effective for the treatment of Vitamin A deficiency. Vitamin A refers to a group of fat-soluble substances that are structurally related to and possess the biological activity of the parent substance of the group called all-trans retinol or retinol. Vitamin A plays vital roles in vision, epithelial differentiation, growth, reproduction, pattern formation during embryogenesis, bone development, hematopoiesis and brain development. It is also important for the maintenance of the proper functioning of the immune system.

Vitamin D ultimately comprises a group of lipid-soluble secosteroids responsible for a variety of biological effects, some of which include increasing the intestinal absorption of calcium, magnesium, and phosphate. With reference to human use, there are 2 main forms of vitamin D - vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol). When non-specific references are made about 'vitamin d', the references are usually about the use of vitamin D3 and/or D2.

Vitamin D3 and D2 require hydroxylation in order to become biologically active in the human body. Since vitamin D can be endogenously synthesized in adequate amounts by most mammals exposed to sufficient quantities of sunlight, vitamin D functions like a hormone on vitamin D receptors to regulate calcium in opposition to parathyroid hormone. Vitamin D plays an essential physiological role in maintaining calcium homeostasis and metabolism. There are several different vitamin D supplements that are given to treat or to prevent osteomalacia and rickets, or to meet the daily criteria of vitamin D consumption.

The in vivo synthesis of the predominant two biologically active metabolites of vitamin D occurs in two steps. The first hydroxylation of vitamin D3 or D2 occurs in the liver to yield 25-hydroxyvitamin D while the second hydroxylation happens in the kidneys to give 1, 25-dihydroxyvitamin D . These vitamin D metabolites subsequently facilitate the active absorption of calcium and phosphorus in the small intestine, serving to increase serum calcium and phosphate levels sufficiently to allow bone mineralization . Conversely, these vitamin D metabolites also assist in mobilizing calcium and phosphate from bone and likely increase the reabsorption of calcium and perhaps also of phosphate via the renal tubules . There exists a period of 10 to 24 hours between the administration of vitamin D and the initiation of its action in the body due to the necessity of synthesis of the active vitamin D metabolites in the liver and kidneys . It is parathyroid hormone that is responsible for the regulation of such metabolism at the level of the kidneys .

Trade Name Multi Vitamin Chewable
Generic Vitamin a + vitamin d + thiamine + riboflavin + niacin + pyridoxine + folic acid + fluoride ion + ascorbic acid + .alpha.-tocopherol acetate + dl- + cyanocobalamin
Type Tablet, chewable
Therapeutic Class
Manufacturer
Available Country United States
Last Updated: September 19, 2023 at 7:00 am
Multi Vitamin Chewable
Multi Vitamin Chewable

Uses

Vitamin C is used for prevention and treatment of scurvy. It may be used for pregnancy, lactation, infection, trauma, burns, cold exposure, following surgery, fever, stress, peptic ulcer, cancer, methaemoglobinaemia and in infants receiving unfortified formulas. It is also prescribed for haematuria, dental caries, pyorrhea, acne, infertility, atherosclerosis, fractures, leg ulcers, hay fever, vascular thrombosis prevention, levodopa toxicity, succinyl-choline toxicity, arsenic toxicity etc. To reduce the risk of stroke in the elderly, long-term supplementation with Vitamin C is essential.

This preparation is used for Pernicious anemia,Vitamin B12 deficiency due to low intake from food,Thyrotoxicosis, Hemorrhage, Malignancy, Liver or kidney disease,Gastric bypass surgery, Total or partial gastrectomy, Gluten enteropathy or sprue, Folic acid deficiency, Macrocytic anaemia

Prophylaxis of megaloblastic anaemia in pregnancy, Supplement for women of child-bearing potential, Folate-deficient megaloblastic anaemia, Prophylaxis of neural tube defect in pregnancy

Therapy with lipid-altering agents should be only one component of multiple risk factor intervention in individuals at significantly increased risk for atheroscleroticvascular disease due to hyperlipidemia. Niacin therapy is used for an adjunct to diet when the response to a diet restricted in saturated fat and cholesterol and other nonpharmacologic measures alone has been inadequate.

  • Niacin is used to reduce elevated TC, LDL-C, Apo B and TG levels, and to increase HDL-C in patients with primary hyperlipidemia and mixed dyslipidemia.
  • In patients with a history of myocardial infarction and hyperlipidemia, niacin is used to reduce the risk of recurrent nonfatal myocardial infarction.
  • In patients with a history of coronary artery disease (CAD) and hyperlipidemia, niacin, in combination with a bile acid binding resin, is used to slow progression or promote regression of atherosclerotic disease.
  • Niacin in combination with a bile acid binding resin is used to reduce elevated TC and LDL-C levels in adult patients with primary hyperlipidemia.
  • Niacin is also used as adjunctive therapy for treatment of adult patients with severe hypertriglyceridemia who present a risk of pancreatitis and who do not respond adequately to a determined dietary effort to control them.

Pyridoxine (vitamin B6) is used to prevent or treat low levels of vitamin B6 in people who do not get enough of the vitamin from their diets. Most people who eat a normal diet do not need extra vitamin B6. However, some conditions (such as alcoholism, liver disease, overactive thyroid, heart failure) or medications (such as isoniazid, cycloserine, hydralazine, penicillamine) can cause low levels of vitamin B6. Vitamin B6 plays an important role in the body. It is needed to maintain the health of nerves, skin, and red blood cells.

Pyridoxine has been used to prevent or treat a certain nerve disorder (peripheral neuropathy) caused by certain medications (such as isoniazid). It has also been used to treat certain hereditary disorders (such as xanthurenic aciduria, hyperoxaluria, homocystinuria).

Preventing and treating riboflavin deficiency and conditions related to riboflavin deficiency.

Cataracts, an eye disorder. People who eat more riboflavin as part of their diet seems to have a lower risk of developing cataracts. Also, taking supplements containing riboflavin plus niacin seems to help prevent cataracts.

High amounts of homocysteine in the blood (hyperhomocysteinemia). Some people are unable to convert the chemical homocysteine into the amino acid methionine. People with this condition, especially those with low riboflavin levels, have high amounts of homocysteine in the blood. Taking riboflavin for 12 weeks seems to reduce homocysteine levels by up to 40% in some people with this condition. Also, certain antiseizure drugs can increase homocysteine in the blood. Taking riboflavin along with folic acid and pyridoxine seems to lower homocysteine levels by 26% in people with high homocysteine levels due to antiseizure drugs.

Migraine headaches. Taking high-dose riboflavin (400 mg/day) seems to significantly reduce the number of migraine headache attacks. However, taking riboflavin does not appear to reduce the amount of pain or the amount of time a migraine headache lasts. Also, taking lower doses of riboflavin (200 mg/day) does not seem to reduce the number of migraine headache attacks.

Thiamine is specifically used in the treatment of the various manifestations of thiamine deficiency such as Beriberi and Wernick's encephalopathy, neuritis associated with pregnancy and pellagra. Supplementary Thiamine may be used prophylactically in conditions where there is low dietary intake or impaired gastro intestinal absorption of thiamine (e.g. alcohol) or where requirements are increased (pregnancy, carbohydrate rich diet).

Effective for:

  • Vitamin A deficiency. Taking vitamin A by mouth is effective for preventing and treating symptoms of vitamin A deficiency. Vitamin A deficiency can occur in people with protein deficiency, diabetes, over-active thyroid, fever, liver disease, cystic fibrosis, or an inherited disorder called abetalipoproteinemia.

Possibly Effective for:

  • Breast cancer. Premenopausal women with a family history of breast cancer who consume high levels of vitamin A in their diet seem to have reduced risk of developing breast cancer. It is not known if taking vitamin A supplements has the same benefit.
  • Cataracts. Research suggests that high intake of vitamin A in the diet is linked to a lower risk of developing cataracts.
  • Diarrhea related to HIV. Taking vitamin A along with conventional medicines seems to decrease the risk of death from diarrhea in HIV-positive children with vitamin A deficiency.
  • Malaria. Taking vitamin A by mouth seems to decrease malaria symptoms in children less than 3 years-old living in areas where malaria is common.
  • Measles. Taking vitamin A by mouth seems to reduce the risk of measles complications or death in children with measles and vitamin A deficiency.
  • Precancerous lesions in the mouth (oral leukoplakia). Research suggests that taking vitamin A can help treat precancerous lesions in the mouth.
  • Recovery from laser eye surgery (photoreactive keratectomy). Taking vitamin A by mouth along with vitamin E seems to improve healing after laser eye surgery.
  • Complications after pregnancy. Taking vitamin A seems to reduce the risk of diarrhea and fever after pregnancy in malnourished women.
  • Complications during pregnancy. Taking vitamin A by mouth seems to reduce the risk of death and night blindness during pregnancy in malnourished women.
  • Eye disease affecting the retina (retinitis pigmentosa). Research suggests that taking vitamin A can slow the progression of an eye disease that causes damage to the retina.

Vitamin D is an ingredient found in a variety of supplements and vitamins.

Vitamin D is indicated for use in the treatment of hypoparathyroidism, refractory rickets (also known as vitamin D resistant rickets), and familial hypophosphatemia .

Multi Vitamin Chewable is also used to associated treatment for these conditions: Common Cold, Deficiency, Vitamin A, Deficiency, Vitamin D, Fever, Flu caused by Influenza, Folate deficiency, Iron Deficiency (ID), Iron Deficiency Anemia (IDA), Oral bacterial infection, Scurvy, Vitamin C Deficiency, Vitamin Deficiency, Nutritional supplementation, Vitamin supplementationAnemia, Anemia, Pernicious, Combined Vitamin B1 and B12 deficiency, Convalescence, Diabetic Neuropathies, Folate deficiency, Iron Deficiency Anemia (IDA), Neuritis, Vitamin B1 deficiency, Vitamin B12 Deficiency, Vitamin B12 concentration, Vitamin B6 Deficiency, Vitamin Deficiency, Nutritional supplementation, Vitamin supplementationDental Cavity, Hypovitaminosis DAnaemia folate deficiency, Folate deficiency, Iron Deficiency (ID), Iron Deficiency Anemia (IDA), Latent Iron Deficiency, Neural Tube Defects (NTDs), Vitamin Deficiency, Methotrexate toxicity, Nutritional supplementationAtherosclerosis, Mixed Dyslipidemias, Myocardial Infarction, Pellagra, Vitamin Deficiency, Primary Hyperlipidemia, Severe Hyperlipidemia, Dietary supplementationBackache, Dizziness, Fever, Headache, Hepatic; Functional Disturbance, Hepatitis, Iron Deficiency Anemia (IDA), Ketosis, Macrocytic anemia, Menière's Disease, Menstrual Distress (Dysmenorrhea), Metabolic Acidosis, Motion Sickness, Nausea and vomiting, Neuralgia, Sciatic, Neuritis, Neurological Conditions caused by B Vitamin Deficiency, Secondary anemia, Soreness, Muscle, Toothache, Toxinfectious state, Trigeminal Neuralgia (TN), Vitamin B1 deficiency, Vitamin B12 Deficiency, Vitamin B6 Deficiency, Vitamin Deficiency, Minor aches and pains, Minor pain, Nutritional supplementation, Supplementation, Vitamin supplementation, Wellness of the LiverAriboflavinosis, Beriberi, Constipation, Functional Gastrointestinal Disorders, Joint Pain, Metabolic cardiomyopathy, Migraine, Neuralgia, Peripheral neuritis, Peripheral paralysis, Soreness, Muscle, Vitamin B complex deficiency, Vitamin B1 deficiency, Vitamin Deficiency, Wernicke's encephalopathy, Dietary and Nutritional Therapies, Nutritional supplementation, Vitamin supplementation, Dietary supplementationAnemia, B12 Deficiency Anemia, Beriberi, Cardiovascular Heart Disease caused by Thiamine Deficiency, Folic Acid Deficiency Anemia, Infantile Beriberi, Infection, Iron Deficiency (ID), Liver disorder, Neuritis caused by Pregnancy, Secondary anemia, Thiamine Deficiency, Vitamin Deficiency, Wernicke's encephalopathy, Nutritional supplementation, Vitamin supplementation, Dietary supplementationDeficiency, Vitamin A, Deficiency, Vitamin D, Degenerative Retinal Disorders, Disorder of the Epithelium, Disorder of the Mesoderm, Inner ear disorder, Vitamin Deficiency, Vitamin E Deficiency, Nutritional supplementationDeficiency, Vitamin D

How Multi Vitamin Chewable works

In humans, an exogenous source of ascorbic acid is required for collagen formation and tissue repair by acting as a cofactor in the posttranslational formation of 4-hydroxyproline in -Xaa-Pro-Gly- sequences in collagens and other proteins. Ascorbic acid is reversibly oxidized to dehydroascorbic acid in the body. These two forms of the vitamin are believed to be important in oxidation-reduction reactions. The vitamin is involved in tyrosine metabolism, conversion of folic acid to folinic acid, carbohydrate metabolism, synthesis of lipids and proteins, iron metabolism, resistance to infections, and cellular respiration.

Vitamin B12 serves as a cofactor for methionine synthase and L-methylmalonyl-CoA mutase enzymes. Methionine synthase is essential for the synthesis of purines and pyrimidines that form DNA. L-methylmalonyl-CoA mutase converts L-methylmalonyl-CoA to succinyl-CoA in the degradation of propionate , an important reaction required for both fat and protein metabolism. It is a lack of vitamin B12 cofactor in the above reaction and the resulting accumulation of methylmalonyl CoA that is believed to be responsible for the neurological manifestations of B12 deficiency . Succinyl-CoA is also necessary for the synthesis of hemoglobin .

In tissues, vitamin B12 is required for the synthesis of methionine from homocysteine. Methionine is required for the formation of S-adenosylmethionine, a methyl donor for nearly 100 substrates, comprised of DNA, RNA, hormones, proteins, as well as lipids . Without vitamin B12, tetrahydrofolate cannot be regenerated from 5-methyltetrahydrofolate, and this can lead to functional folate deficiency , . This reaction is dependent on methylcobalamin (vitamin B12) as a co-factor and is also dependent on folate, in which the methyl group of methyltetrahydrofolate is transferred to homocysteine to form methionine and tetrahydrofolate. Vitamin B12 incorporates into circulating folic acid into growing red blood cells; retaining the folate in these cells . A deficiency of vitamin B12 and the interruption of this reaction leads to the development of megaloblastic anemia.

Folic acid, as it is biochemically inactive, is converted to tetrahydrofolic acid and methyltetrahydrofolate by dihydrofolate reductase (DHFR). These folic acid congeners are transported across cells by receptor-mediated endocytosis where they are needed to maintain normal erythropoiesis, synthesize purine and thymidylate nucleic acids, interconvert amino acids, methylate tRNA, and generate and use formate. Using vitamin B12 as a cofactor, folic acid can normalize high homocysteine levels by remethylation of homocysteine to methionine via methionine synthetase.

Niacin performs a number of functions in the body and so has many mechanisms, not all of which have been fully described. Niacin can decrease lipids and apolipoprotein B (apo B)-containing lipoproteins by modulating triglyceride synthesis in the liver, which degrades apo B, or by modulating lipolysis in adipose tissue.

Niacin inhibits hepatocyte diacylglycerol acyltransferase-2. This action prevents the final step of triglyceride synthesis in hepatocytes, limiting available triglycerides for very low density lipoproteins (VLDL). This activity also leads to intracellular degradation of apo B and decreased production of low density lipoproteins, the catabolic product of VLDL.

Niacin also inhibits a high density lipoprotein (HDL) catabolism receptor, which increases the levels and half life of HDL.

Vitamin B6 is the collective term for a group of three related compounds, pyridoxine (PN), pyridoxal (PL) and pyridoxamine (PM), and their phosphorylated derivatives, pyridoxine 5'-phosphate (PNP), pyridoxal 5'-phosphate (PLP) and pyridoxamine 5'-phosphate (PMP). Although all six of these compounds should technically be referred to as vitamin B6, the term vitamin B6 is commonly used interchangeably with just one of them, pyridoxine. Vitamin B6, principally in its biologically active coenzyme form pyridoxal 5'-phosphate, is involved in a wide range of biochemical reactions, including the metabolism of amino acids and glycogen, the synthesis of nucleic acids, hemogloblin, sphingomyelin and other sphingolipids, and the synthesis of the neurotransmitters serotonin, dopamine, norepinephrine and gamma-aminobutyric acid (GABA).

Binds to riboflavin hydrogenase, riboflavin kinase, and riboflavin synthase. Riboflavin is the precursor of flavin mononucleotide (FMN, riboflavin monophosphate) and flavin adenine dinucleotide (FAD). The antioxidant activity of riboflavin is principally derived from its role as a precursor of FAD and the role of this cofactor in the production of the antioxidant reduced glutathione. Reduced glutathione is the cofactor of the selenium-containing glutathione peroxidases among other things. The glutathione peroxidases are major antioxidant enzymes. Reduced glutathione is generated by the FAD-containing enzyme glutathione reductase.

It is thought that the mechanism of action of thiamine on endothelial cells is related to a reduction in intracellular protein glycation by redirecting the glycolytic flux. Thiamine is mainly the transport form of the vitamin, while the active forms are phosphorylated thiamine derivatives. Natural derivatives of thiamine phosphate, such as thiamine monophosphate (ThMP), thiamine diphosphate (ThDP), also sometimes called thiamine pyrophosphate (TPP), thiamine triphosphate (ThTP), and thiamine triphosphate (AThTP), that act as coenzymes in addition to their each unique biological functions.

Vision:Vitamin A (all-trans retinol) is converted in the retina to the 11-cis-isomer of retinaldehyde or 11-cis-retinal. 11-cis-retinal functions in the retina in the transduction of light into the neural signals necessary for vision. 11-cis-retinal, while attached to opsin in rhodopsin is isomerized to all-trans-retinal by light. This is the event that triggers the nerve impulse to the brain which allows for the perception of light. All-trans-retinal is then released from opsin and reduced to all-trans-retinol. All-trans-retinol is isomerized to 11-cis-retinol in the dark, and then oxidized to 11-cis-retinal. 11-cis-retinal recombines with opsin to re-form rhodopsin. Night blindness or defective vision at low illumination results from a failure to re-synthesize 11-cis retinal rapidly.
Epithelial differentiation: The role of Vitamin A in epithelial differentiation, as well as in other physiological processes, involves the binding of Vitamin A to two families of nuclear retinoid receptors (retinoic acid receptors, RARs; and retinoid-X receptors, RXRs). These receptors function as ligand-activated transcription factors that modulate gene transcription. When there is not enough Vitamin A to bind these receptors, natural cell differentiation and growth are interrupted.

Most individuals naturally generate adequate amounts of vitamin D through ordinary dietary intake of vitamin D (in some foods like eggs, fish, and cheese) and natural photochemical conversion of the vitamin D3 precursor 7-dehydrocholesterol in the skin via exposure to sunlight.

Conversely, vitamin D deficiency can often occur from a combination of insufficient exposure to sunlight, inadequate dietary intake of vitamin D, genetic defects with endogenous vitamin D receptor, or even severe liver or kidney disease . Such deficiency is known for resulting in conditions like rickets or osteomalacia, all of which reflect inadequate mineralization of bone, enhanced compensatory skeletal demineralization, resultant decreased calcium ion blood concentrations, and increases in the production and secretion of parathyroid hormone . Increases in parathyroid hormone stimulates the mobilization of skeletal calcium and the renal excretion of phosphorus . This enhanced mobilization of skeletal calcium leads towards porotic bone conditions .

Ordinarily, while vitamin D3 is made naturally via photochemical processes in the skin, both itself and vitamin D2 can be found in various food and pharmaceutical sources as dietary supplements. The principal biological function of vitamin D is the maintenance of normal levels of serum calcium and phosphorus in the bloodstream by enhancing the efficacy of the small intestine to absorb these minerals from the diet . At the liver, vitamin D3 or D2 is hydroxylated to 25-hydroxyvitamin D and then finally to the primary active metabolite 1,25-dihydroxyvitamin D in the kidney via further hydroxylation . This final metabolite binds to endogenous vitamin d receptors, which results in a variety of regulatory roles - including maintaining calcium balance, the regulation of parathyroid hormone, the promotion of the renal reabsorption of calcium, increased intestinal absorption of calcium and phosphorus, and increased calcium and phosphorus mobilization of calcium and phosphorus from bone to plasma to maintain balanced levels of each in bone and the plasma .

Dosage

Multi Vitamin Chewable dosage

vitamin C is usually administered orally. When oral administration is not feasible or when malabsorption is suspected, the drug may be administered IM, IV, or subcutaneously. When given parenterally, utilization of the vitamin reportedly is best after IM administration and that is the preferred parenteral route.

For intravenous injection, dilution into a large volume parenteral such as Normal Saline, Water for Injection, or Glucose is recommended to minimize the adverse reactions associated with intravenous injection.

The average protective dose of vitamin C for adults is 70 to 150 mg daily. In the presence of scurvy, doses of 300 mg to 1 g daily are recommended. However, as much as 6 g has been administered parenterally to normal adults without evidence of toxicity.

To enhance wound healing, doses of 300 to 500 mg daily for a week or ten days both preoperatively and postoperatively are generally considered adequate, although considerably larger amounts have been recommended. In the treatment of burns, doses are governed by the extent of tissue injury. For severe burns, daily doses of 1 to 2 g are recommended. In other conditions in which the need for vitamin C is increased, three to five times the daily optimum allowances appear to be adequate.

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever the solution and container permit.

Usual Adult Dose for Pernicious Anemia

Initial dose: 1000 mcg intramuscularly or deep subcutaneous once a day for 6 to 7 daysIf clinical improvement and reticulocyte response is seen from the above dosing:

  • 100 mcg every other day for 7 doses, then
  • 100 mcg every 3 to 4 days for 2 to 3 weeks, then
  • Maintenance dose: 100 to 1000 mcg monthly

Administer concomitant folic acid if needed. Chronic treatment should be done with an oral preparation in patients with normal intestinal absorption.

Usual Adult Dose for B12 Nutritional Deficiency: 25 to 2000 mcg orally daily

Usual Adult Dose for Schilling Test: 1000 mcg intramuscularly is the flushing dose

Usual Pediatric Dose for B12 Nutritional Deficiency: 0.5 to 3 mcg daily

Supplement for women of child-bearing potential: 0.4 mg daily.

Folate-deficient megaloblastic anaemia: 5 mg daily for 4 mth, up to 15 mg daily in malabsorption states. Continued dosing at 5 mg every 1-7 days may be needed in chronic haemolytic states, depending on the diet and rate of haemolysis.

Prophylaxis of neural tube defect in pregnancy: 4 or 5 mg daily starting before pregnancy and continued through the 1st trimester.

Prophylaxis of megaloblastic anaemia in pregnancy: 0.2-0.5 mg daily.

Niacin can be administered as a single dose at bedtime, after a snack or meal and doses should be individualized according to patient response. Therapy with Niacin must be initiated at 500 mg in order to reduce the incidence and severity of side effects which may occur during early therapy.

Maintenance Dose: The daily dosage of Niacin should not be increased by more than 500 mg in any 4-week period. The recommended maintenance dose is 1000 mg (two 500 mg tablets or one 1000 mg tablet) to 2000 mg (two 1000 mg tablets or four 500 mg tablets) once daily at bedtime. Doses greater than 2000 mg daily are not recommended. Women may respond at lower Niacin doses than men.

Single-dose bioavailability studies have demonstrated that two of the 500 mg and one of the 1000 mg tablet strengths are interchangeable but three of the 500 mg and two of the 750 mg tablet strengths are not interchangeable.

Flushing of the skin may be reduced in frequency or severity by pretreatment with aspirin (up to the recommended dose of 325 mg taken 30 minutes prior to Niacin dose). Tolerance to this flushing develops rapidly over the course of several weeks. Flushing,pruritus, andgastrointestinaldistress are also greatly reduced by slowly increasing the dose of niacin and avoiding administration on an empty stomach. Concomitant alcoholic, hot drinks or spicy foods may increase the side effects of flushing and pruritus and should be avoided around the time of Niacin ingestion.

Equivalent doses of Niacin should not be substituted for sustained-release (modified-release, timed-release) niacin preparations or immediate-release (crystalline) niacin. Patients previously receiving other niacin products should be started with the recommended Niacin titration schedule, and the dose should subsequently be individualized based on patient response.

If Niacin therapy is discontinued for an extended period, reinstitution of therapy should include a titration phase.

ADULTS:

BY MOUTH:

  • For hereditary sideroblastic anemia: Initially, 200-600 mg of vitamin B6 is used. The dose is decreased to 30-50 mg per day after an adequate response.
  • For vitamin B6 deficiency: In most adults, the typical dose is 2.5-25 mg daily for three weeks then 1.5-2.5 mg per day thereafter. In women taking birth control pills, the dose is 25-30 mg per day.
  • For abnormally high levels of homocysteine in the blood: For reducing high levels of homocysteine in the blood after childbirth, 50-200 mg of vitamin B6 has been taken alone. Also, 100 mg of vitamin B6 has been taken in combination with 0.5 mg of folic acid.
  • For preventing macular degeneration: 50 mg of vitamin B6 in the form of pyridoxine has been used daily in combination with 1000 mcg of vitamin B12 (cyanocobalamin) 1000 mcg and 2500 mcg of folic acid for about 7 years.
  • For hardening of the arteries (atherosclerosis): A specific supplement (Kyolic, Total Heart Health, Formula 108, Wakunga) containing 250 mg of aged garlic extract, 100 mcg of vitamin B12, 300 mcg of folic acid, 12.5 mg of vitamin B6, and 100 mg of L-argininedaily for 12 months.
  • For kidney stones: 25-500 mg of vitamin B6 has been used daily.
  • For nausea during pregnancy: 10-25 mg of vitamin B6 taken three or four times per day has been used. In people who don't respond to vitamin B6 alone, a combination product containing vitamin B6 and the drug doxylamine (Diclectin, Duchesnay Inc.) is used three or four times per day. Also, another product containing 75 mg of vitamin B6, 12 mcg of vitamin B12, 1 mg of folic acid, and 200 mg of calcium (PremesisRx, KV Pharmaceuticals) is used daily.
  • For symptoms of premenstrual syndrome (PMS): 50-100 mg of vitamin B6 is used daily, alone or along with 200 mg of magnesium.
  • For treating tardive dyskinesia: 100 mg of vitamin B6 per day has been increased weekly up to 400 mg per day, given in two divided doses.

INJECTED INTO THE MUSCLE:

  • Hereditary sideroblastic anemia: 250 mg of vitamin B6 daily, reduced to 250 mg of vitamin B6 weekly once adequate response is achieved.

CHILDREN:

BY MOUTH:

  • For kidney stones: Up to 20 mg/kg daily in children aged 5 years and up.

INJECTED INTO THE VEIN OR MUSCLE:

  • For seizures that respond to vitamin B6 (pyridoxine-dependent seizures): 10-100 mg is recommended.

The daily recommended dietary allowances (RDAs) of vitamin B6 are:

  • Infants 0-6 months, 0.1 mg
  • Infants 7-12 months, 0.3 mg
  • Children 1-3 years, 0.5 mg
  • Children 4-8 years, 0.6 mg
  • Children 9-13 years, 1 mg
  • Males 14-50 years, 1.3 mg
  • Males over 50 years, 1.7 mg
  • Females 14-18 years, 1.2 mg
  • Females 19-50 years, 1.3 mg
  • Females over 50 years, 1.5 mg
  • Pregnant women, 1.9 mg
  • Breast-feeding women, 2 mg
  • Some researchers think the RDA for women 19-50 years should be increased to 1.5-1.7 mg per day.

The recommended maximum daily intake is:

  • Children 1-3 years, 30 mg
  • Children 4-8 years, 40 mg
  • Children 9-13 years, 60 mg

Adults, pregnant and breast-feeding women:

  • 14-18 years, 80 mg
  • over 18 years, 100 mg

For treating low levels of riboflavin (riboflavin deficiency) in adults: 5-30 mg of riboflavin (Vitamin B2) daily in divided doses.

For preventing migraine headaches: 400 mg of riboflavin (Vitamin B2) per day. It may take up to three months to get best results.

For preventing cataracts: a daily dietary intake of approximately 2.6 mg of riboflavin (Vitamin B2) has been used. A combination of 3 mg of riboflavin (Vitamin B2) plus 40 mg of niacin daily has also been used.

The daily recommended dietary allowances (RDAs) of riboflavin (Vitamin B2) are:

  • Infants 0-6 months: 0.3 mg
  • Infants 7-12 months: 0.4 mg
  • Children 1-3 years: 0.5 mg
  • Children 4-8 years: 0.6 mg
  • Children 9-13 years: 0.9 mg
  • Men 14 years or older: 1.3 mg
  • Women 14-18 years: 1 mg
  • Women over 18 years: 1.1 mg
  • Pregnant women: 1.4 mg
  • Breastfeeding women: 1.6 mg

Prophylaxis: 3 to 10 mg daily.

Mild chronic deficiency: 10 to 25 mg daily.

Severe deficiency: 200 to 300 mg daily.

Vitamin A deficiency For severe deficiency with corneal changes: 500,000 unit/day for 3 days, followed by 50,000 unit/day for 2 wk and then 10,000-20,000 unit/day for 2 mth as follow-up therapy.

For cases without corneal changes: 10,000-25,000 unit/day until clinical improvement occurs (usually 1 -2 wk).

May be taken with or without food.

Niacin tablets should be taken whole and should not be broken, crushed or chewed before swallowing.

Side Effects

Ascorbic acid does not seem to have any important adverse effects at dosages less than 4 mg/day. Larger dose may cause diarrhoea or formation of renal calculi of calcium oxalate in patients with renal impairment. Ingestion of more than 600 mg daily have a diuretic action.

Arthralgia (12%), Dizziness (12%), Headache (12%), Nasopharyngitis (12%), Anaphylaxis, Angioedema, Congestive heart failure, Peripheral vascular disease,Pulmonary edema, Diarrhea, Dyspepsia, Polycythemia vera, Sore throat, Nervousness, Rhinitis, Glossitis, Hypoesthesia

GI disturbances, hypersensitivity reactions; bronchospasm.

Niacin is generally well tolerated; adverse reactions have been mild and transient.The most frequent advers effects were flushing, itching, pruritis, nausea and GI upset, jaundice ,hypotension, tachycardia, increased serum blood glucose and uric acid levels, myalgia.

Pyridoxine usually has no side effects when used in recommended doses.

If your doctor has prescribed this medication, remember that he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Pyridoxine can cause side effects when taken in large doses for a long time. Tell your doctor right away if any of these unlikely but serious side effects occur: headache, nausea, drowsiness, numbness/tingling of arms/legs.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat. Riboflavin may cause your urine to turn a yellow-orange color, but this is usually not a harmful side effect.

Vitamin B1 does not have adverse effects when given orally, but in a few fatal cases anaphylactic reactions have occurred after intravenous administration of large doses (400 mg) in sensitive patients, especially children, and in one case following an intramuscular dose of 125 mg. The risk of such reactions increases with repeated administration of the drug by parenteral route. Transient mild soreness may occur at the site of intramuscular administration

Hypervitaminosis A characterised by fatigue, irritability, anorexia, weight loss, vomiting and other Gl disturbances, low-grade fever, hepatosplenomegaly, skin changes, alopoecia, dry hair, cracking and bleeding lips, SC swelling, nocturia, pains in bones and joints.

Toxicity

LD50 Oral (mouse): > 5,000 mg/kg .

General toxicity

Vitamin B12 is generally non-toxic, even at higher doses. Mild, transient diarrhea, polycythemia vera, peripheral vascular thrombosis, itching, transitory exanthema, a feeling of swelling of entire body, pulmonary edema and congestive heart failure in early treatment stages, anaphylactic shock and death have been observed after vitamin B12 administration .

Carcinogenesis and mutagenesis

Long term studies in animals examining the carcinogenic potential of any of the vitamin B12 formulations have not completed to date. There is no evidence from long-term use in patients with pernicious anemia that vitamin B12 has carcinogenic potential. Pernicious anemia is known to be associated with an increased incidence of stomach carcinoma, however, this malignancy has been attributed to the underlying cause of pernicious anemia and has not been found to be related to treatment with vitamin B12 .

Use in pregnancy

No adverse effects have been reported with ingestion of normal daily requirements during pregnancy .

A note on the use of the nasal spray in pregnancy

Although vitamin B12 is an essential vitamin and requirements are increased during pregnancy, it is currently unknown whether the nasal spray form can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. The nasal spray form should be given to a pregnant woman only if clearly needed, as it is considered a pregnancy category C drug in this form. Sufficient well-controlled studies have not been done to this date in pregnant women .

Use in lactation

Vitamin B12 has been found distributed into the milk of nursing women in concentrations similar to the maternal blood vitamin B12 concentrations. No adverse effects have been reported to date with intake of normal required doses during lactation .

IPR-MUS LD50 85 mg/kg,IVN-GPG LD50 120 mg/kg, IVN-MUS LD50 239 mg/kg, IVN-RAT LD50 500 mg/kg, IVN-RBT LD50 410 mg/kg

Overdose of niacin may present with severe prolonged hypotension. Patients experiencing an overdose should be treated with supportive measures which may include intravenous fluids.

The oral LD50 in the mouse is 3720mg/kg, in the rabbit is 4550mg/kg, in the rat is 7000mg/kg, and the dermal LD50 in the rat is >2000mg/kg.

Oral Rat LD50 = 4 gm/kg. Toxic effects include convulsions, dyspnea, hypermotility, diarrhea, ataxia and muscle weakness.

Thiamine toxicity is uncommon; as excesses are readily excreted, although long-term supplementation of amounts larger than 3 gram have been known to cause toxicity. Oral mouse LD50 = 8224 mg/kg, oral rat LD50 = 3710 mg/kg.

Acute toxicity to vitamin A can occur when adults or children ingest >100x or >20x the RDA, respectively, over a period of hours or a few days. The RDA for vitamin A differs depending on age and sex and can range from 300 - 900 μg retinol activity equivalents (RAE) per day. Symptoms of acute systemic toxicity generally include mucocutaneous involvement (e.g. xerosis, cheilitis, skin peeling) and may involve mental status changes. Children are typically more susceptible to acute vitamin A toxicity - daily intakes of as little as 1500 IU/kg have been observed to result in toxicity.

Chronic vitamin A toxicity can develop following the long-term ingestion of high vitamin A doses. While there is a wide variation in the lowest toxic vitamin A dose, the ingestion of >25 000 IU daily for 6 years or 100,000 IU daily for 6 months is considered to be toxic. Chronic vitamin A toxicity can affect many organ systems and can lead to the development of osteoporosis and CNS effects (e.g. headaches).

The use of pharmacological or nutraceutical vitamin d and/or even excessive dietary intake of vitamin d is contraindicated in patients with hypercalcemia, malabsorption syndrome, abnormal sensitivity to the toxic effects of vitamin d, and hypervitaminosis D .

Hypersensitivity to vitamin d is one plausible etiologic factor in infants with idiopathic hypercalcemia - a case in which vitamin d use must be strictly restricted .

As vitamin d intake is available via fortified foods, dietary supplements, and clinical drug sources, serum concentrations and therapeutic dosages should be reviewed regularly and readjusted as soon as there is clinical improvement . Dosage levels are required to be individualized on an individual patient by patient basis as caution must be exercised to prevent the presence of too much vitamin d in the body and the various potentially serious toxic effects associated with such circumstances .

In particular, the range between therapeutic and toxic doses is quite narrow in vitamin d resistant rickets . When high therapeutic doses are used, progress should be followed with frequent blood calcium determinations .

When treating hypoparathyroidism, intravenous calcium, parathyroid hormone, and/or dihydrotachysterol may be required .

Maintenance of normal serum phosphorus levels by dietary phosphate restriction and/or administration of aluminum gels as intestinal phosphate binders in those patients with hyperphosphatemia as frequently seen in renal osteodystrophy is essential to prevent metastatic calcification .

Mineral oil interferes with the absorption of lipid-soluble vitamins, including vitamin d preparations .

The administration of thiazide diuretics to hypoparathyroid patients who are concurrently being treated with vitamin d can result in hypercalcemia .

At this time, no long term animal studies have been performed to evaluate vitamin potential for carcinogens, mutagenesis, or fertility .

As various animal reproduction studies have demonstrated fetal abnormalities in several species associated with hypervitaminosis D, the use of vitamin d in excess of the recommended dietary allowance during normal pregnancy should be avoided . The safety in excess of 400 USP units of vitamin d daily during pregnancy has not been established . The abnormalities observed are similar to the supravalvular aortic stenosis syndrome described in infants that is characterized by supravalvular aortic stenosis, elfin facies, and mental retardation .

In a nursing mother given large doses of vitamin D, 25-hydroxycholecalciferol appeared in the milk and caused hypercalcemia in her child. Caution is subsequently required when contemplating the use of vitamin d in a nursing woman, and the necessity of monitoring infants' serum calcium concentration if vitamin d is administered to a breastfeeding woman .

Adverse reactions associated with the use of vitamin d are primarily linked to having hypervitaminosis D occurring [FDA Lanel]. In particular, hypervitaminosis D is characterized by effects specific effects on specific organ systems. At the renal system, hypervitaminosis D can cause impairment of renal function with polyuria, nocturne, polydipsia, hypercalciuria, reversible asotemia, hypertension, nephrocalcinosis, generalized vascular calcification, or even irreversible renal insufficiency which may result in death . Elsewhere, hypervitaminosis D can also cause CNS mental retardation . At the level of soft tissues, it can widespread calcification of the soft tissues, including the heart, blood vessels, renal tubules, and lungs . In the skeletal system, bone demineralization (osteoporosis) in adults can occur while a decline in the average rate of linear growth and increased mineralization of bones, dwarfism, vague aches, stiffness, and weakness can occur in infants and children . Finally, hypervitaminosis D can also lead to nausea, anorexia, and constipation at the gastrointestinal level as well as mild acidosis, anemia, or weight loss via metabolic processes .

The LD(50) in animals is unknown .

Precaution

Ingestion of megadose (more than 1000 mg daily) of vitamin C during pregnancy has resulted in scurvy in neonates. Vitamin C in mega-doses has been contraindicated for patients with hyperoxaluria. Vitamin C itself is a reactive substance in the redox system and can give rise to false positive reactions in certain analytical tests for glucose, uric acid, creatine and occult blood.

Intensive treatment of B12-deficient megaloblastic anemia may cause hypokalemia and sudden death. Use with caution in patients with Leber optic nerve atrophy. Thrombocytosis may occur with treatment of severe vitamin B12 megaloblastic anemia

Treatment resistance may occur in patients with depressed haematopoiesis, alcoholism, deficiencies of other vitamins. Neonates.

Before instituting therapy with Niacin, an attempt should be made to control hyperlipidemia with appropriate diet, exercise, and weight reduction in obese patients and to treat other underlying medical problems. Patients with a past history of jaundice, hepatobiliary disease, or peptic ulcer should be observed closely during Niacin therapy. Frequent monitoring of liver function tests and blood glucose should be performed to ascertain that the drug is producing no adverse effects on these organ systems. Diabetic patients may experience a dose-related rise in glucose intolerance, the clinical significance of which is unclear. Diabetic or potentially diabetic patients should be observed closely. Adjustment of diet and/or hypoglycemic therapy may be necessary.

Caution should also be used when Niacin is used in patients with unstable angina or in the acute phase of MI, particularly when such patients are also receiving vasoactive drugs such as nitrates, calcium channel blockers or adrenergic blocking agents. Elevated uric acid levels have occurred with Niacin therapy, therefore use with caution in patients predisposed to gout. Niacin has been associated with small but statistically significant dose-related reductions in platelet count and increases in prothrombin time. Caution should be observed when Niacin is administered concomitantly with anticoagulants; prothrombin time and platelet counts should be monitored closely in such patients. Niacin has been associated with small but statistically significant, dose-related reductions in phosphorus levels (mean of -13% with 2000 mg). So phosphorus levels should be monitored periodically in patients at risk.

Before taking pyridoxine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

During pregnancy, this vitamin has been found to be safe when used in recommended doses.

This vitamin passes into breast milk and is considered to be safe during breast-feeding when used in recommended doses. Consult your doctor for more information.

Cholestatic jaundice; fat-malabsorption conditions. Monitor patients closely for toxicity. Liver impairment and children.

Interaction

Potentially hazardous interactions: Ascorbic acid is incompatible in solution with aminophylline, bleomycin, erythromycin, lactobionate, nafcillin, nitrofurantoin sodium, conjugated oestrogen, sodium bicarbonate, sulphafurazole diethanolamine, chloramphenicol sodium succinate, chlorthiazide sodium and hydrocortisone sodium succinate.

Useful interactions: Ascorbic acid increases the apparent half-life of paracetamol and enhances iron absorption from the gastrointestinal tract.

Absorption reduced by antibiotics, aminosalicylic acid, anticonvulsants, biguanides, cholestyramine, cimetidine, colchicine, K salts, methyldopa.

Antiepileptics, oral contraceptives, anti-TB drugs, alcohol, aminopterin, methotrexate, pyrimethamine, trimethoprim and sulphonamides may result to decrease in serum folate contrations. Decreases serum phenytoin concentrations.

Niacin may potentiate the effects of ganglionic blocking agents and vasoactive drugs resulting in postural hypotension. Concomitant aspirin may decrease the metabolic clearance of nicotinic acid. The clinical relevance of this finding is unclear. About 98% of available Niacin was bound to colestipol, with 10 to 30% binding to cholestyramine. These results suggest that 4 to 6 hours, or as great an interval as possible, should elapse between the ingestion of bile acid-binding resins and the administration of Niacin.

The effects of some drugs can change if you take other drugs or herbal products at the same time. This can increase your risk for serious side effects or may cause your medications not to work correctly. These drug interactions are possible, but do not always occur. Your doctor or pharmacist can often prevent or manage interactions by changing how you use your medications or by close monitoring.

To help your doctor and pharmacist give you the best care, be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products) before starting treatment with this product. While using this product, do not start, stop, or change the dosage of any other medicines you are using without your doctor's approval.

Some products that may interact with this vitamin include: altretamine, cisplatin, phenytoin.

This vitamin may interfere with certain laboratory tests (including urine test for urobilinogen), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this vitamin.

Rate and extent of absorption may be affected by propantheline bromide.

No hazardous drug interactions have been reported. Vitamin B1 acts synergistically with other vitamins of the B-complex group and its potential for causing adverse effects is considerably reduced.

Decreased absorption with neomycin. Increased risk of hypervitaminosis A with synthetic retinoids eg, acitretin, isotretinoin and tretinoin. Increased risk of toxicity when used with alcohol.

Volume of Distribution

Cobalamin is distributed to tissues and stored mainly in the liver and bone marrow .

Tetrahydrofolic acid derivatives are distributed to all body tissues but are stored primarily in the liver.

Data regarding the volume of distribution of niacin is not readily available.

Pyridoxine main active metabolite, pyridoxal 5’-phosphate, is released into the circulation (accounting for at least 60% of circulating vitamin B6) and is highly protein bound, primarily to albumin.

Elimination Route

70% to 90%

Vitamin B12 is quickly absorbed from intramuscular (IM) and subcutaneous (SC) sites of injection; with peak plasma concentrations achieved about 1 hour after IM injection .

Orally administered vitamin B12 binds to intrinsic factor (IF) during its transport through the stomach. The separation of Vitamin B12 and IF occurs in the terminal ileum when calcium is present, and vitamin B12 is then absorbed into the gastrointestinal mucosal cells. It is then transported by transcobalamin binding proteins . Passive diffusion through the intestinal wall can occur, however, high doses of vitamin B12 are required in this case (i.e. >1 mg). After the administration of oral doses less than 3 mcg, peak plasma concentrations are not reached for 8 to 12 hours, because the vitamin is temporarily retained in the wall of the lower ileum .

Folic acid is absorbed rapidly from the small intestine, primarily from the proximal portion. Naturally occurring conjugated folates are reduced enzymatically to folic acid in the gastrointestinal tract prior to absorption. Folic acid appears in the plasma approximately 15 to 30 minutes after an oral dose; peak levels are generally reached within 1 hour.

In patients with chronic kidney disease, the Cmax is 0.06µg/mL for a 500mg oral dose, 2.42µg/mL for a 1000mg oral dose, and 4.22µg/mL for a 1500mg oral dose. The Tmax is 3.0 hours for a 1000mg or 1500mg oral dose. The AUC is 1.44µg*h/mL for a 500mg oral dose, 6.66µg*h/mL for a 1000mg oral dose, and 12.41µg*h/mL for a 1500mg oral dose. These values did not drastically differ in patients requiring dialysis.

The B vitamins are readily absorbed from the gastrointestinal tract, except in malabsorption syndromes. Pyridoxine is absorbed mainly in the jejunum. The Cmax of pyridoxine is achieved within 5.5 hours.

Vitamin B2 is readily absorbed from the upper gastrointestinal tract.

Absorbed mainly from duodenum, by both active and passive processes

Readily absorbed from the normal gastrointestinal tract

Vitamin D3 and D2 are readily absorbed from the small intestine (proximal or distal) .

Half Life

16 days (3.4 hours in people who have excess levels of vitamin C)

Approximately 6 days (400 days in the liver) .

The half life of niacin is 0.9h, nicotinuric acid is 1.3h, and nicotinamide is 4.3h.

The total adult body pool consists of 16 to 25 mg of pyridoxine. Its half-life appears to be 15 to 20 days.

66-84 minutes

1.9 hours

Although certain studies suggest the half-life of 1,25-hydroxyvitamin D3 may be approximately 15 hours, the half-life of 25-hydroxyvitamin D3 appears to have a half-life of about 15 days . Intriguingly however, the half-lives of any particular administration of vitamin d can vary and in general the half-lives of vitamin D2 metabolites have been demonstrated to be shorter overall than vitamin D3 half-lives with this being affected by vitamin d binding protein concentrations and genotype in particular individuals .

Clearance

During vitamin loading, the kidney accumulates large amounts of unbound vitamin B12. This drug is cleared partially by the kidney, however, multiligand receptor megalin promotes the reuptake and reabsorption of vitamin B12 into the body , .

Data regarding the clearance of niacin is not readily available.

Some studies propose an estimated clearance rate for 1,25-dihydroxyvitamin D as 31 +/- 4 ml/min in healthy adults .

Elimination Route

This drug is partially excreted in the urine . According to a clinical study, approximately 3-8 mcg of vitamin B12 is secreted into the gastrointestinal tract daily via the bile. In patients with adequate levels of intrinsic factor, all except approximately 1 mcg is reabsorbed. When vitamin B12 is administered in higher doses that saturate the binding capacity of plasma proteins and the liver, the unbound vitamin B12 is eliminated rapidly in the urine. The body storage of vitamin B12 is dose-dependent .

After a single oral dose of 100 mcg of folic acid in a limited number of normal adults, only a trace amount of the drug appeared in the urine. An oral dose of 5 mg in 1 study and a dose of 40 mcg/kg of body weight in another study resulted in approximately 50% of the dose appearing in the urine. After a single oral dose of 15 mg, up to 90% of the dose was recovered in the urine. A majority of the metabolic products appeared in the urine after 6 hours; excretion was generally complete within 24 hours. Small amounts of orally administered folic acid have also been recovered in the feces. Folic acid is also excreted in the milk of lactating mothers.

69.5% of a dose of niacin is recovered in urine. 37.9% of the recovered dose was N-methyl-2-pyridone-5-carboxamide, 16.0% was N-methylnicotinamide, 11.6% was nicotinuric acid, and 3.2% was niacin.

The major metabolite of pyridoxine, 4-pyridoxic acid, is inactive and is excreted in urine

The primary excretion route of vitamin D is via the bile into the feces .

Pregnancy & Breastfeeding use

The drug is safe in normal doses in pregnant women, but a daily intake of 5 gm or more is reported to have caused abortion. The drug may be taken safely during lactation.

Pregnancy Category A. Adequate and well-controlled human studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters).

Lactation: Drug distributed in milk.

Pregnancy Category A. Adequate and well-controlled human studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters).

Niacin cannot be used in pregnancy and lactation because of a lack of information.

Category A: Controlled studies in women fail to demonstrate a risk to the foetus in the 1st trimester (and there is no evidence of a risk in later trimesters), and the possibility of foetal harm remains remote.

Riboflavin is LIKELY SAFE for pregnant or breast-feeding women when taken in the amounts recommended. The recommended amounts are 1.4 mg per day for pregnant women and 1.6 mg per day in breast-feeding women. Riboflavin is POSSIBLY SAFE when taken by mouth in larger doses, short-term. Some research shows that riboflavin is safe when taken at a dose of 15 mg once every 2 weeks for 10 weeks.

The drug may be given safely to neonates, children, pregnant and lactating women and elderly patients.

Pregnancy Category A. Adequate and well-controlled human studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters).

Contraindication

Leber's disease, tobacco amblyopia.

Undiagnosed megaloblastic anaemia; pernicious, aplastic or normocytic anaemias.

Niacin is contraindicated in patients with a known hypersensitivity to Niacin or any component of this medication, significant or unexplained hepatic dysfunction, active peptic ulcer disease or arterial bleeding.

There is no absolute contraindication but the risk of anaphylaxis is increased by repeated parenteral administration. Mild allergic phenomena, such as sneezing or mild asthma are warning signs that further may give rise to anaphylactic shock. To avoid this possibility it is advisable to start a second course of injection with a dose considerably lower than that previously used. Because of the above, vitamin B1 injection should not be given intravenously except in the case of comatose patients. Once thiamine deficiency is corrected there is no need for parenteral administration or for the administration of amounts in excess of daily requirement.

Hypervitaminosis A; pregnancy (dose exceeding RDA).

Acute Overdose

Supportive measures should be undertaken in the event of an overdosage. Symptoms may include nausea, dizziness, itching, vomiting, upset stomach, and flushing

Storage Condition

Should be stored in a dry place below 30˚C.

Store at 15-30° C.

Store at 15-30° C.

Thiamine injection should be protected from light and moisture.

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