Vitamin D Supplements Don't Help Your Health: Review

[frazzled]

15. Not entirely

More than three years ago a select committee convened by the Institute of Medicine at the request of the US and Canadian governments did an extensive study, which was reported on the front page of the New York Times. (I remember reading it, because my doctor had prescribed Vitamin D for me.) It stated some of the findings mentioned above (the unnecessariness, the unhelpfulness, the potential harm), but it also discussed the fact that, because doctors were routinely ordering tests of Vitamin D levels, it was being prescribed like wildfire. Yet, the levels used to determine who was deficient were often way off. So don't necessarily believe it if your doctor says you are deficient.

And these days more and more people know their vitamin D levels because they are being tested for it as part of routine physical exams.

“The number of vitamin D tests has exploded,” said Dennis Black, a reviewer of the report who is a professor of epidemiology and biostatistics at the University of California, San Francisco.

At the same time, vitamin D sales have soared, growing faster than those of any supplement, according to The Nutrition Business Journal. Sales rose 82 percent from 2008 to 2009, reaching $430 million. “Everyone was hoping vitamin D would be kind of a panacea,” Dr. Black said. The report, he added, might quell the craze.

...

Some labs have started reporting levels of less than 30 nanograms of vitamin D per milliliter of blood as a deficiency. With that as a standard, 80 percent of the population would be deemed deficient of vitamin D, Dr. Rosen said. Most people need to take supplements to reach levels above 30 nanograms per milliliter, he added.

But, the committee concluded, a level of 20 to 30 nanograms is all that is needed for bone health, and nearly everyone is in that range.

http://www.nytimes.com/2010/11/30/health/30vitamin.html