Shine Calcium with Vitamin D Mechanism of Action

Pharmacology: (Summary of Pharmacodynamics and Pharmacokinetics): Calcium is essential for the functional integrity of the nervous, muscular and skeletal systems. Healthy adults on normal diets do not need oral calcium supplement. However, these may be needed in lactating and pregnant women, and in patients with osteomalacia, rickets and hypocalcemia secondary to hypoparathyroidism or vitamin D deficiency.
Vitamin D₃ is essential for promoting the absorption and utilization of calcium and phosphate and for normal calcification of bone. It maintains normal concentration of calcium and phosphate in the plasma by facilitating their absorption from the small intestine, enhancing their mobilization from bone and decreasing their excretion by the kidney.
Approximately one-fifth to one-third of orally administered calcium is absorbed in the small intestine, depending on the presence of vitamin D metabolites, pH lumen, and on dietary factors such as calcium binding to fibers or phytates. Calcium absorption is increased when a calcium deficiency is present or when a patients is on low calcium diet. In patients with achlorhydria of hypochlorhydria, calcium absorption, especially in the carbonate salt, may be reduced.
Vitamin D is absorbed from the renal intestine. Absorption is reduced in impaired hepatic or biliary function. Before vitamin can exert its physiological action it is converted to one or more of its metabolites. Excretion of vitamin D and its metabolites is mainly in the bile and only small amounts are eliminated in the urine.