Medicine & HealthVitamin D Important In Brain Development And Function:
McCann & Ames point out that evidence for vitamin D's involvement in brain function includes the wide distribution of vitamin D receptors throughout the brain. They also discuss vitamin D's ability to affect proteins in the brain known to be directly involved in learning and memory, motor control, and possibly even maternal and social behavior. The review also discusses studies in both humans and animals that present suggestive though not definitive evidence of cognitive or behavioral consequences of vitamin D inadequacy. The authors discuss possible reasons for the apparent discrepancy between the biological and behavioral evidence, and suggest new, possibly clarifying avenues of research.
As you might know, it seems that most dark-skinned people at higher latitudes have a deficiency. Also, tests of natural selection seem to suggest that humans have become far lighter over the past 10-20,000 years. Why?
Here's the citation:
McCann, JC, Ames BN (2008) Review Article: Is there convincing biological or behavioral evidence linking vitamin D deficiency to brain dysfunction" FASEB J. 22: 982-1001.
The paper is not online yet....
A word of caution: many nutrients are involved in thousands of biochemical pathways. The main reason I focus on Vitamin D is that the data for selection of lighter skin at northern latitudes is very powerful....
Comments
With vitamin D you must be careful, it isn't water soluble. The best is you get it in a right amount, enough time outside and right food. See my post about vitamins: www.sikantis.net
Posted by: sikantis | April 21, 2008 9:38 PM
I have always felt that people who wear clothes all the time were a bit slow. Now I know why. LOL.
Posted by: Art | April 21, 2008 11:01 PM
sikantis,
You are basing this comment on outdated research. Vitamin D is a prohormone, not a vitamin.
With vitamin D you must be careful, it isn't water soluble. The best is you get it in a right amount, enough time outside and right food.
If you want good information on vitamin d go to http://www.vitamindcouncil.org
Debbie in Indiana.
Posted by: Hoosierville | April 22, 2008 8:18 AM
I wonder how much effect this would have on dark skinned minorities living in Northern climates in Europe and North America? What variance in IQ would we see in people who are lactose intolerant or do not commonly drink milk as part of their diet, even as kids?
Posted by: Longma | April 22, 2008 6:29 PM
The Canadian government released a study that shows most blacks, Indians, and East Asians have vitamin D deficiency, I'm guessing the darker the people, the higher on average the deficiency.
http://www.straight.com/article-132921/immigrants-face-health-risks
Posted by: Longma | April 22, 2008 6:52 PM
The Canadian government released a study that shows most blacks, Indians, and East Asians have vitamin D deficiency, I'm guessing the darker the people, the higher on average the deficiency.
yeah, i've linked to that. i live in the northern USA and eat a lot of fish and try to get sun. was still vit. d deficiency. the reason i was checked wuz that my dr. was an olive skinned person of italian ancestry who had the same problem.
Posted by: razib | April 22, 2008 6:54 PM
Do we enjoy sunbathing because we want a tan or we know instinctively that it produces Vitamin D?
Posted by: terry | April 22, 2008 7:31 PM
Do we enjoy sunbathing because we want a tan or we know instinctively that it produces Vitamin D?
association with leisured elite. relatively recent fashion. normally dark skin is associated with low class field work in mostly agrarian societies.
Posted by: razib | April 22, 2008 7:41 PM
On a tangential note: I've seen several comments from American soldiers that the local Iraqis have very poor direction skills. These comments were made in the context that Iraqi soldiers often couldn't participate effectively in night raids, because they often got confused about directions and were a liability. The same Iraqis performed fine during the daytime.
Is there any reason why this might be the case? I say this as an American with woeful directional abilities. And as bad as they are during the day, my night skills are even worse. My father, on the other hand, can orient like a hawk.
Posted by: jim | April 23, 2008 12:11 AM