Vitamin D deficiency in India: fortify or let the sun shine in?

Vitamin D plays a pivotal role in calcium and mineral metabolism. It is astonishing to find vitamin D deficiency in India despite plentiful sunlight. This could probably because of urbanization, life style and dress code changes, and revision of vitamin D adequacy range. Recent studies in south India using in vitro ampoule model with 7-dehydrocholesterol have shown adequate formation of active form of vitamin D in mid-day sun. In India 70% of populations reside in rural areas. Only 35% of Indian populations have access to regulated milk supply. We as humans can get vitamin D from abundant sunshine, by exposing 18% of body surface area (without sunscreen) to mid-day sun for 30-45 min to cause 1 minimal erythemal dose (MED) which is equivalent to taking about 600 to 1000 IU of vitamin D. This is about the recommended daily dose by expert group on human nutrient requirements and the dose used in studies with fortified milk supplementation studies. Vitamin D synthesized in the skin lasts two-times longer in the body. In populations where there is limited exposure to sunlight, like dress-code limiting sun-exposure, usage of sunscreen with (SPF) greater than 8 etc., vitamin D supplementation may also be required. Since there is widespread calcium deficiency in Indian population, calcium supplementation should be an integral part of vitamin D supplementation therapy.