Re-thinking dietary (=supplemental) vitamin D
Hitherto, the only Joes and Janes who have profoundly benefited from this one-(XL-)size-fits-it-all approach are the producers of respective supplements. Convincing scientific data from controlled studies which would show that the consumption of large amounts >1.000 IU of vitamin D capsule or pill form, exert any verifiable health benefit for someone with normal (or even low-normal) vitamin D levels is absent. The (remote?) possibility that there actually is no benefit, aside, there are yet a few other possible explanations why - epidemiological data aside - scientific evidence for the benefits of vitamin D3 supplementation in a non-vitamin-D-deficient cohort is still lacking:
- Lack of financial interest from the side of the pharma companies: Vitamin D is obviously non-patentable and if it could, as many people believe, prevent diabetes, stroke, heart disease and cancer, the use of respective supplements would obviously put the pharmaceutical industry out of business.
Note: The pharmaceutical industry has already been trying to come up with patentable vitamin D analogues, of which they claim that they would lack the largely non-existent negative side-effects of the real vitamin - I guess, you can you tell which way the wind is blowing?!
Financial revenue could thusly be a major factor, as it is obviously pretty costly to set up a tightly controlled, appropriately powered randomized, placebo-controlled study on healthy people. Even large scale epidemiological studies, on the other hand, can be done by a group of graduate students, by just plugging into respective databases and doing some more or less sophisticated statistical evaluations on existing data sets.
- Insufficient dosing or study periods that are simply too short to yield results: I have, in the past seen studies, even I, as a avowing skeptic, would not cite to underline my argument that we do not have enough scientific evidence that supplemental vitamin D is not the savior people may make you believe. I mean, if you assign a group of say 20 people to 400IU of vitamin D for 4 weeks and see no changes in a handful of pretty random markers of health and disease, this is unquestionably not an argument against the potential usefulness of vitamin D supplementation.
- Adding vitamin D3 supplements to a "healthy" low fat diet: Assuming that this point has immediately caught your eye, I want to encourage you to read the rest of this blogpost, as this, i.e. the necessity of adequate amounts of dietary fat, to absorb vitamin D3 is what the rest of this post will revolve around.
|Image 2: Who would buy all those toxic, but expensive drugs, if it turned out that by taking a non-patentable "vitamin" the diseases they were invented for could be prevented?|
|Figure 1: 25(OH)D levels of 30 healthy men and women after ingestion of 50.000IU vitamin D3 supplement in conjunction with a normal or low fat breakfast (data calculated based on Raimundo. 2011)|
No fat, no sun, no vitamin D - regardless of supplementation
|Image 3: Get your D from the sun, if you can!|
And while the scientists concede that the small scale of the study, the lack of detailed recordings of the subjects' dietary vitamin D intake in the course of the 14-day follow up period and the reliance on 25(OH)D level as single surrogate for serum vitamin D levels (remember that we are actually talking about a whole host of "vitamins D") are limitations of their study, Raimondo et al. are nevertheless right to conclude that their "findings can have important implications to define the adequate dietary intake of vitamin D"... implications, which may well go beyond the mere recomendation to take your vitamin D with fat. After all, increased absorption would mean decreased need for supplementation and who knows whether you could not easily satisfy your dietary vitamin D requirements without any supplements, if you just set the "low-to-no fat, no dangerous organ meats" dietary recommendations at naught?