Vitamin D is a fat-soluble vitamin which is essential for calcium and phosphorus metabolism.
It occurs as ergocalciferol (Vitamin D2) and cholecalciferol (Vitamin D3).
Ergocalciferol (Vitamin D2) manufactures from ergosterol of plants,
And cholecalciferol (Vitamin D3) manufactures from the cholesterol of the animals by the action of ultraviolet rays.
Sources of Vitamin D:
The sources of Vitamin D are as follows:
1. Foods: Fish, liver, egg, butter and oils are the good sources of Vitamin D.
Fish liver oil is the richest source of vitamin D.
2. Sunlight: Vitamin D is synthesized in our skin by the action of U.V. rays on 7-dehydrocholesterol.
Daily requirements of Vitamin D:
The RDA for adults 5mg cholecalciferol or 200 International units (IU) of Vitamin D.
Children, pregnant women and lactating mother require 1ųg cholecalciferol or 400 International units (IU).
Functions of Vitamin D:
Vitamin D is essential for the metabolism of calcium and phosphorous and normal mineralization of bones and teeth.
It increases intestinal absorption of calcium and phosphorous.
Deficiency of Vitamin D causes Rickets (in children) and Osteomalacia (in adult).
Excessive intake of Vitamin D for long periods may lead to anorexia, nausea, vomiting, thirst, constipation and drowsiness.
- We should expose our children to sunlight regularly.
- We should provide those foods which are rich in Vitamin D to our children, pregnant women and lactating mother.
- If deficiency happens we also cover it by giving vitamin D tablets.