Friday, November 4, 2011

Vitamin D: Too Much of a Good Thing

Way back in the good ol' days, we learned about vitamin D intoxication as part of the differential diagnosis for hypercalcemia.  But in our present time, we hear more often about vitamin D deficiency, especially given our propensity to work indoors and slather ourselves w/sunscreen prior to stepping outside.  Don't get me wrong.  I'm all for sunscreen to minimize the risk of skin cancer (and those dreaded wrinkles).  But I suspect that one unintended consequence is vitamin D deficiency.

Given how much press vitamin D has received over the last several years, and given the push by nutraceutical supplement manufacturers to promote their wares as necessities to improve our lifespan, and given that no manufacturers have to prove safety, much less efficacy, in their products before bringing them to market (they're natural, after all!), it amazes me that we haven't heard more frequently about vitamin D (and other fat soluble vitamin) intoxication (although we've heard plenty about other contaminated supplements), typically manifest as hypercalcemia.  So perhaps, the manufacturers are finally doing their part?

Well, in an article published early online prior to print next month in JCEM, the authors report of two patients presenting w/severe hypercalcemia.  In both cases, each patient denied taking any medications.  It was only upon repeated questioning that they admitted to taking dietary supplements.  In fact, these were prescribed outside their local area, in one case, by someone out of this country, and in the other, via Internet.  More importantly, one of the patients didn't think to mention his hormones until much later when asked repeatedly about medications.

Depending upon the laboratory equipment used, the normal reference range for 25OH vitamin D can be 30-80ng/mL.  One patient presented with a level at 1,220ng/mL while the other had 645ng/mL.  No wonder they were symptomatic of hypercalcemia!  And through no fault of their own since one manufacturer labeled its product as containing 1,600IU when it actually contained 186,400IU per serving upon independent testing.  The other product was labeled as 1,000IU per serving but independent testing demonstrated 970,000IU.  Of course, neither product had passed United States Pharmacopeia testing or some other 3rd party oversight.

Lest you think otherwise, I'm all for supplementing appropriately, but under supervision using products manufactured under 3rd party oversight.  Check and be sure that your supplements have the appropriate stamp.  It's not an absolute guarantee against manufacturing issues, but it's the best we have at this time.  And depending upon your perspective, tell your family physician about all your nutritional supplements or ask your patients specifically about the same (and hormones, too).



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3 comments:

  1. Interesting take on things Dr Alvin, I have often said it's best to get vitamin D from natural sources and some supplements are often filled with cheap substances to bulk them out, however I do see some benefits to the supplement route for those on special diets

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  2. My goodness! Two whole patients with dangerous Vitamin D levels (and one of those was due to a PHARMACY error, not a manufacturing error). I have no intention to downplay the risk of major, extended overdoses of Vitamin D, but you do nothing in your article to promote healthy doses. You simply mention how to see if a product has been "properly" evaluated. How about giving some guidelines, including mention of the fact that the US government has even upped its recommendations for Vitamin D intake? It turns out that a healthy adult can easily take 5000 IU each and every day for extended periods of time, and likely not even exceed the upper limit of the "normal" level on a 25(OH)D test.

    You might want to familiarize yourself with the Vitamin D Council, and perhaps even contact John Cannell, MD, its founder. There you will find legitimate, scientifically-based information about Vitamin D levels, supplementation vs. sun, toxicity, etc. In the meantime, you gave grossly insufficient information from which a reader could make any decisions, and served more to scare people away from use of Vitamin D when the facts show far more cases of severe consequences of inadequate levels of Vitamin D, compared to the two cases you cite. Personally, I've taken 5000 IU daily for several years now, and my most recent test shows a quite-normal 64 ng/ml with a lab-supplied reference range of 32-100 (not 30-80 as stated in your article). Just MY 2¢....

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  3. (2nd try - first one disappeared)
    WOW! Two whole cases of dangerously high Vitamin D levels resulting in serious medical consequences (there were actually three - one was "Dr." Gary Null who OD'd on one of his own products, allegedly manufactured with grossly high levels of Vitamin D, despite the labeling). And one of your cited cases was due to a pharmacist's error, not taking more than what was appropriate based on the labeled amount in the product.

    Your article does not address the positives, such as the fact that the US government, every-so-slow to move normally, has actually increased the officially recommended minimum intake of Vitamin D. Nor does your article state that regular use of amounts as high as 4000-5000 IU per day of Vitamin D3, IS NOT DANGEROUS. Personally, I've taken 5000 units virtually ever day for years, and my most recent lab test came back at 64 ng/mL (reference range of 32-100, unlike your article's 30-80 range). Either way, I'm totally safe.

    You might want to familiarize yourself with John Cannell, MD, founder of the Vitamin D Council, and his work that is scientifically based. It's clear that you could learn a great deal from him, or else that you'd at least be more motivated to present a more balanced story. Two whole OD cases in the midst of untold medical (and unnecessary Child Protective Services) cases that could have been completely avoided with MORE Vitamin D. Your article unnecessarily scares people, and potentially results in even more medical problems due to UNDER-use of Vitamin D, rather than the exceptionally rare (two, maybe three if you count Gary Null) severe overdose.

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