Gracal

Uses

Calcium citrate is an ingredient found in a variety of supplements and vitamins.

For use as an over the counter calcium supplement.

Gracal is also used to associated treatment for these conditions: Calcium Deficiency, Deficiency of Vitamin D3, Deficiency, Vitamin D, Folate deficiency, Hypocalcemia, Iron Deficiency (ID), Osteoporosis

How Gracal works

Calcium citrate increases plasma calcium levels. This reduces calcium flux from osteocyte activity by reducing the secretion of parathyroid hormone (PTH) . Calcium does this by stimulating a G-protein coupled calcium receptor on the surface of parathyroid cells. The reduction in calcium flux increases the amount of calcium deposited in bone resulting in an increase in bone mineral density. The reduction in PTH secretion also reduces the amount of vitamin D metabolized to its active form, calcidiol. Since calcidiol increases the expression of calcium dependent ATPases and transient receptor potential cation channel subfamily V member 6 (TRPV6) both of which are involved in calcium uptake from the gut, a reduction in calcidiol results in less calcium absorption. Additionally, TRPV5, the channel responsible for calcium reabsorption in the kidney, is downregulated when PTH secretion is reduced thus increasing calcium excretion via the kidneys. Another hormone, calitonin, is likely involved in the reduction of bone resorption during periods of high plasma calcium.

Toxicity

Patients taking more than 4g of calcium a day are at risk of hypercalcemia and metabolic alkalosis . Chronic intake of calcium supplements is associated with adverse gastrointestinal symptoms such as constipation and flatulence .

Elimination Route

The percentage of calcium absorbed varies inversely with intake . Tmax of about 3.5-5h varying with formulation .

Elimination Route

Cleared via the kidneys but largely reabsorbed (98-99%) under normal conditions .

Innovators Monograph

You find simplified version here Gracal