Vitamin D refers to a group of several different forms of this vitamin. It is also popularly known as the sunshine vitamin. A modest exposure to sunlight, as less as 5 minutes is sufficient for the body to convert the cholesterol present in the skin to Vitamin D, using the ultraviolet rays of the sun. The British Dietetics Association recommends about 15 minutes exposure thrice a week between 11am to 3pm.
Vitamin D may be classified as a vitamin but it also acts as a hormone in the body, regulating the calcium and phosphorus levels of our blood. Sterols in lipids of animals (7-dehydrocholesterol) are converted to Vitamin D3 and those in plants (ergosterols) are converted to Vitamin D2.
Vitamin D3 is primarily involved in the maintenance of calcium and phosphorus balance in our body whereas Vitamin D3 is involved in the regulation of more than 50 genes, one of which is the gene for calcium binding protein Calbindi.
Vitamin D is measured in micrograms. ICMR recommends supplementation of 10 micrograms/ day in case of minimal exposure to sun. It also observes that outdoor activities should be taken up to get maximum exposure to sunlight, especially in urban India.
Food Sources of Vitamin D
Here’s a list of the food sources of Vitamin D –
Food VIT D2+D3(µg) /100g
Fish oil, cod liver 250
Shiitake mushroom dried 3.9
Buttermilk (whole milk) 1.3
Cheddar/ Parmesan 0.6
USDA DatabaseOther than this, foods fortified with Vitamin D will also provide some amount. Typically milk, soy milk, cheese, yogurt, margarines and butters are the chosen food for fortification. Read the labels.
Vitamin D Deficiency
Vitamin D deficiency results in Rickets in babies and children, which is characterised by imperfect bone formation resulting in bow legs. In the older population, Vitamin D deficiency result in Osteomalacia or softening of bones as the minerals required for keeping them strong do not enter the bones. Scientific research also suggests that low levels of Vitamin D increases the risk of colorectal cancer in men and breast cancer in women.
Supplementation of Vitamin D should be taken under medical supervision.