Vitamin D & calcium supplements: Less is more?

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Celebrity Vitamin D advocate Gwyneth Paltrow may (or may not) have a legitimate deficiency of the nutrient, but the notion of a pervasive problem of vitamin D and calcium deficiency in U.S. adults, along with the broad spectrum of health benefits associated with supplementation, is largely media hype, according to a recent report by a committee of the Institute of Medicine (IOM).

The IOM assessed the latest data on calcium and vitamin D supplements, and concluded that North Americans tend to acquire enough of these nutrients from their diet, although sunlight is helpful in augmenting the body’s own production of vitamin D. The supplements' only benefit, according to the report, lies in improved bone health. In fact, the committee warns against toxicity associated with excessive intake, such as kidney and liver damage from too much vitamin D. Specifically, survey results show that post-menopausal women may ingest excessive amounts of calcium from supplements, ultimately increasing their risk of kidney stones. With the exception of girls ages 9-18, most people take in enough calcium through their diets, while North Americans tend to get enough vitamin D from daily sun exposure and fortified foods. Dismissing recent data calling for a minimum vitamin D level of 40-50 nanograms per milliliter blood (ng/mL) as “inconsistent and/or conflicting,” the IOM committee recommends a 20-30 ng/mL standard for good bone health — which nearly 80 percent of the population achieves, says committee member Dr. Clifford J. Rosen.

ACSH's Dr. Gilbert Ross adds, “We’ve been reading so much recently about the myriad benefits of vitamin D that I was starting to think we’d have to add it to the water, along with statins. Seriously, it’s good to gain a little perspective on the evidence-basis for all the hype. We should pause before rushing to put everyone on mega-dose vitamin D — wait until the data is collected.”