Vitamin D: Don’t Overdo a Good Thing

Came across a sensible article on vitamin D supplementation today. Thanks, Jeff!

Vitamin D: Don’t Overdo a Good Thing by Tod Cooperman, M.D.


“It seems that initial reports led some experts to ignore the recommendation of the National Academies’ Institute of Medicine, which says that only people with vitamin D levels under 20 ng/mL are deficient. Instead, these experts argued that people need to maintain levels which are at least 50 percent higher–30 ng/mL….Further feeding this frenzy have been clinical laboratories — which profit from more vitamin D tests. When you get a vitamin D test back, the “normal” range shown next to your result often extends up to 100 ng/mL (which is actually far beyond the normal range), leading people with levels in the 20s, for example, to believe they needed more vitamin D.”

2 Responses to “Vitamin D: Don’t Overdo a Good Thing”

  1. Brandon Becker Says:

    My yearly laboratory blood work lists the reference for vitamin D of <20 to be "deficient" with <30 to be "insufficient" based on the recommendations of the Endocrine Society.

    Seeing this caused me to drastically increase my vitamin D supplementation to increase my blood levels from the teens to mid 20s after one year and nearly 50 after two years. I noticed my mood becoming more irritable with higher blood levels, so I drastically cut back supplementation and also switched back from D3 to D2. My levels thankfully dropped to around 40 last year and around 30 this year.

    I should be in the IOM normal range of 20s now and am relying on limited sun exposure and your recommended levels of supplementation with D2 to maintain my levels. I feel safer in this normal range and my mood is back to normal, too.

  2. Brandon Becker Says:

    I just found this article that IOM committee members wrote to disagree with the Endocrine Society’s vitamin D recommendations:

    I wish I would have seen this back in 2012 so I could have been satisfied with my vitamin D levels in the 20s.

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