Calcium carbonate is a calcium supplement that is applied within deficiency states and as an adjunct in the prevention and treatment of osteoporosis. Vitamin D3 represents it supports, A fat, Soluble sterol the regulation of calcium and phosphate homeostasis and bone mineralisation. Absorption calcium carbonate about 15, 25% gets absorbed in the gi tract. Converted to calcium chloride by gastric acid. Vitamin d well, Absorbed in the gi tract in the availability of bile. Metabolism vitamin d undergoes hydroxylation in the hepatic organ and kidney to form the active metabolite, 1, 25, Dihydrocolecalciferol. Excretion vitamin d and metabolites are mainly excreted in the bile and faeces. Calcium carbonate, Vitamin d3 adverse reactions / calcium carbonate, Vitamin d3 side effects constipation, Flatulence, Nausea, Abdominal pain and rash and, Diarrhoea. Pruritus urticaria.