Vitamin D Deficiency In Sun Drenched India– Can D-Lightful Sunlight Be a Respite? – Sunlight D Lemma

Vitamin D is one of the oldest hormones; 500 million-years old phytoplankton species in Sargasso Sea were found to contain large amount of ergosterol (vitamin D 2 precursor).Ergosterol is transferred along the food chain into the sea food, where it is stored and concentrated.Vitamin D was essential for calcium and bone homeostasis to cope with higher gravity in terrestrial animals.In humans Vitamin D is synthesized on exposure to mid-day sunlight (UV-B rays 290-315 nm).The widespread vitamin D deficiency [25(OH)D< 20 ng/ml] in India appear to be due to changes in lifestyle-sun shy attitude, dress code and, lack of dietary calcium.Experimental studies from India have shown that, Indians can synthesise enough vitamin D on exposure to sunlight.Vitamin D orchestrates the "Ca-vitamin D-Parathyroid hormone endocrine axis.Calcitriol, the active form of vitamin D follows either of the two-pathways.Genomic responses-takes anything from few hours to days to become fully manifest (osseous benefits); Chemical messengers that transmits signals and rapid responses (RR) which vary from few seconds to an hour (non-osseous benefits e.g., insulin secretion, intestinal calcium absorption).Association with vitamin D deficiency has been reported in hypertension, diabetes, psoriasis, Chron's disease, multiple sclerosis, prostatic and colonic cancer.For osseous benefits the vitamin D levels should be above >20ng/ml, while for non-osseous benefit requires 25(OH)D levels >30 ng/ml.Adequate dietary calcium intake of 1gm/day has to be ensured.