Although I trust the "consensus" among the paleo community that Vitamin D supplementation is critical - and myself and family members have been supplementing because of this - I've recently started to become a little dubious about the D3 supplements. My reasons for this odd feeling are:

1) No discernable change in my body since I began supplementing
2) The fact that D3 is, suddenly, being pushed by big pharma and the other usual suspects who advocate harmful things, and
3) All of the non-paleo sources I've heard advocating Vitamin D3 actually go one step further and say that endogenous D3 (from the sun) is bad, and supplementation is the only way you can get good Vitamin D3 (this is in direct contrast to Dr. Michael Eades, who noted that endogenous Vitamin D is much healthier and has a larger half-life).

Then, on this week's Robb Wolf podcast, a question referred to a Mercola article which straight-up said that Vitamin D3 supplementation is bad. I know that Mercola is prone to hyperbole, but overall I do trust him.

Robb Wolf didn't have much of a reply, but he did note that, like many molecules, there are actually two versions of D3: mirrored "left/right" versions. I know that in amino acids, the left- or right orientation of the molecule is literally a deciding factor whether your body can use it for proteins or if it's waste. So could it be that the synthetic D3 we're consuming is the wrong mirrored version and, therefore, it's just waste (or even worse)?

I believe this is of great importance because of how fervently Vitamin D3 is being advocated. I'm not quick to jump on the bandwagon, and yet even I was so convinced about it that I told everybody in my family to begin supplementing.

So it would be fantastic to learn of a molecular analysis of the synthetic Vitamin D3 many of us buy and see whether it is indeed the proper shape for human consumption. Does anybody know of such an analysis? If one does not exist, it would be great to have a team of chemists do their thing.

Here's the podcast. The discussion begins at roughly the 11:30 mark:

Carbohydrate Requirement for Type 1 Diabetic Children - Episode 153