Friday, September 14, 2007

Vitamin D deficiency in India   posted by Razib @ 9/14/2007 03:39:00 AM

Last week I talked about the fact that a significant proportion of the within population variance of skin color in South Asians is due to a mutant allele which is also responsible for a significant fraction of the between population difference for Europeans and Africans. This mutant allele on SLC24A5 has gone to fixation within the last 10,000 years in Europeans, and increased to great proportions along a broad great swath of southwestern Eurasia and into northern Africa. What's going on here? A friend commented, "Well, it isn't like there is going to be Vitamin D deficiency in India." That seems plausible enough...except I just stumbled onto this paper, High prevalence of vitamin D deficiency among pregnant women and their newborns in northern India. The authors chalk up the lack to their diet. I've already suggested nutrient deprivation with the switch to agriculture triggered the spread of the light skin variants in other contexts, and with the presence of the background condition of Vitamin D deficiency possibly driven by diet perhaps evolution is still going on in India?