Saturday, December 04, 2010

Is Vit D the Cleave Issue of Paleo?

Great Shot by Michael Herb
A lot of paleosphere bloggers have been lambasting the Institute of Medicine's recent recommendation of 600 IU as the adult RDA and a 25-hydroxy blood serum of 20 ng/ml, notably Richard Nikoley and Dr William Davis (I'm not sure Dr Davis would consider himself a paleo blogger, but he is, in my mind at least).

I myself supplement with Carlson vit D3 tablets, 2000 IU a day and try to get some daily sun, to the point of putting a mattress under the window in the summer to catch a few afternoon rays when at home with my kid (he loves laying in the sun). I did notice that my skin seemed more resistant to sunburn than it used to be--although Granny was from Bandon, Ireland, and I inherited her skin, so sunburns will always be a threat.

My father got skin cancer and so did my uncle, both half Irish and grew up in Albuquerque way back when kids actually played outside all day long, Yet I still believe that not getting enough sun is a way bigger problem than getting too much. And I think sunscreen is just makes things worse.

Still, the whole thing vit D supplementation thing makes me somewhat uneasy. When a precept like the necessity of vit D supplementation becomes an assumed fact without much evidence to back it up, well, that starts to smack of dogma.

I'm still a little bit on the fence about vit D supplementation. There is some evidence that vit D supplementation is beneficial, but vit D hasn't had a thorough double-blind placebo controlled study because there just hasn't been the cash available as there would be for testing a drug or effect on cancer or all that cash pumped into proving that SFAs cause CHD. Or at least that's what the dogmatists claim!!!!! Just kidding,

Nigel Kinbrum has a great post about his positive vit D experience, with an insane amount of links to studies at the bottom (and I mean insane, perhaps vit D is responsible for his having the energy to create that many links).

I agree that vit D is important but the whole "you are a goddamn (I was going to write fuckin' but my mother thinks I shouldn't curse on my blog (Hi Mom! Liam loved the robots)) idiot if you don't crank up your vit D levels to such-and-such" attitude makes my spidey-sense tingle just a bit.

SFA bad! I think that myth has long since been laid to rest. Vit D supplementation? Probably a good idea but the jury is still out in my opinion.


Addendum: just came across this article by Chris Masterjohn (courtesy of Tim's comment on Richard's blog). Money quote: "But if you are trying desperately to maintain year-round 25(OH)D status between 50-80 ng/mL using vitamin D supplements, you have entered the land of speculation.  Enter at your own risk."

I really hate clichés like "ahead of the curve", but if anyone is currently ahead of the curve in nutrition research (and writes about it on the internet) it has to be this guy.

6 comments:

  1. thanks for mentioning me. I do think Vit D is supper important.

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  2. Hi! I found you via my traffic monitor.

    I'm of the belief that you can never have too many studies. :-D

    Cheers, Nige.

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  3. Hi Nigel,

    I agree, the more the merrier.

    When I first came across your excellent blog, I thought, this guy is concise and logical, then I saw you were also a EE and it all made sense.

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  4. I have always preferred sunlight to the idea of artificially high D3 levels ( oral supplementation). The relevant D level at the cell is 1,25 which is dependent on local activation. Therefore, while I think that supplementation is better than no sun, 30 ng/dl is probably a more reasonable target than the 60 or 70 that some go for. I now supplement with 2000 a day but just in the latter part of winter. It does not make sense to argue that we have white skin to obtain D in the north but if we live in the north we all require supplementation. I also think Peter's idea that D may only correct grain related pathology has some merit.

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  5. "It does not make sense to argue that we have white skin to obtain D in the north"

    I believe John Hawks brought up this point a while back, that if white skin in northern climes was so important, then the Inuits would have quickly evolved very white skin, which they haven't. I'd be quite interested to hear more on this.

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