EVOLUTIONARY ADAPTATIONS: THE IMPACT OF LIGHTER SKIN:
It would take someone with dark skin of African or South Asian ancestry about 60 minutes at the same time of day to make the amount of vitamin D that a person of European ancestry would make in about 10 minutes, estimates Reinhold Vieth, one of Canada's top vitamin D experts and a professor in the department of nutritional sciences at the University of Toronto.
You probably know of Vitamin D deficiency for rickets, but I think more common ailments might have a major fitness impact:
VDR ligands have also been shown to increase the activity of natural killer cells, and enhance the phagocytic activity of macrophages...Active vitamin D hormone also increases the production of cathelicidin, an antimicrobial peptide that is produced in macrophages triggered by bacteria, viruses, and fungi...Vitamin D deficiency tends to increase the risk of infections, such as influenza and tuberculosis. In a 1997 study, Ethiopian children with rickets were 13 times more likely to get pneumonia than children without rickets
More like this
Winter is upon us and so is the risk of vitamin D deficiency and infections.
I dont understand people who view food as medicine.
Well, I mean, I guess I do. Theyre terrified of disease X/Y/Z (even if X/Y/Z is treatable/preventable with modern medicine), and they think a component of food helps treat/prevent disease X/Y/Z, so they religiously eat said food.
Over at the NYTimes Well blog they have a really good summary of studies about vitamins and improvements to health.
I got interested in vitamin D a few years ago because I was trying to figure out a plausible explanation for why many of the genetic variants implicated in lighter skin seem to have risen in frequency relatively recently, 10,000 years ago, when modern humans have been extant at higher latitudes o
Interesting, I was born with Rickets, and had bowed legs as a toddler, almost died of pneumonia at ages 2 and 12 and had infleunza every year till my late teens, and colds most of the time - I guess vitamin D is implicated.