Gene Expression



There are two counterposing factors for me when processing these sorts of medical findings. First, I am cautious about overreacting based on new medical research, because so much of this ends up overturned upon second-look as there are various confounds and variables unaccounted for. Second, I believe there are strong evolutionary hints that Vitamin D deficiency causes some serious reductions in fitness on the physiological/health margins. What I mean is that there is a wealth of data that the genetic variants which are implicated in lighter complexion have been powerfully driven by natural selection within the last 10,000 years in various human populations. It seems to me that the most plausible model to explain this genetic change is an environmental reduction in Vitamin D and this micronutrient’s essential role in sustaining immune health. But most plausible does not mean the correct, so we must weight that prior accordingly. Additionally, most modern humans are not living on the physiological marings, we’re healthy and wealthy, so we can take nutrient hits (if they are hits) without putting our lives at risk. Of course, if you are dark-skinned, that’s another prior you should pump in, because it is almost assured that you have a deficiency if you reside at temperate latitudes.

For the record, I am actually taking 2,000 IU Vitamin D pills every day to keep my levels up. That’s the dosage recommended in this research for adolescents.


  1. #1 Oldfart
    May 27, 2008

    Science Daily, I am sad to say, has been dispensing an inordinate amount of woo lately so be careful of anything you read there. Consider the original source. For instance, they list as a science article papers published in the Journal of Alternative and Complementary Medicine, a known sCAMmer rag.

  2. #2 razib
    May 27, 2008

    Journal of Clinical Endocrinology & Metabolism ? have no idea about medical journals….

  3. #3 JC
    May 27, 2008

    what do you make of this critique:

    Seems the author thinks there is a conflict of interest by the scientists conducting vitamin d studies.

  4. #4 razib
    May 27, 2008

    it seems a lot of the micronutrient stuff is riddled with this. i can’t see how we can prevent it though….

    like i said, just keep piling up the priors. i can bring some info on the evolutionary genomic possibilites.

  5. #5 Oldfart
    May 27, 2008

    I wasn’t really commenting on your article or on this particular SD article. Just that I have noticed more woo than usual on SD lately. Maybe I just wasn’t aware before. I read SD more carefully now or, more accurately, I check the references more closely now.

  6. #6 Alan
    May 28, 2008

    There’s an evolutionary angle here. The Inuit, for example, who reside where sunlight exposure is minimal much of the year, consume vitamin D-rich seafood, and their skin contains more melanin than say, the average Scandinavian. Eating the right seafood, such as wild salmon, would appear to be an optimal way to get appropriate levels of vitamin D.

  7. #7 diana
    May 30, 2008

    I saw a prominent oncologist on TV yesterday recommending 2000 units. I can’t remember his name, sorry.

    Why am I allofasudden hearing about Vitamin D everywhere?
