Vitamin D- Provitamins, active form, functions, Rickets, serum level, RDA, sources

Provitamins Ergocalciferol and Cholecalciferol transport and storage ad 25- OH Cholecalciferol Active form- Calcitriol Functions on three target tissues Intestinal cell- increases absorption of calcium Bone- Mineralization of bones Kidney- increases tubular absorption of calcium increases serum calcium level Deficiency manifestation Rickets in children Osteomalacia in adult RDA- 400 IU in children, 200 IU in Adult Sources- Sunlight, fish, egg yolk etc.