Follow the science they said but there was no science to follow

From Study Finds Another Condition That Vitamin D Pills Do Not Help by Gina Kolata.  

The idea made so much sense it was almost unquestioningly accepted: Vitamin D pills can protect bones from fractures. After all, the body needs the vitamin for the gut to absorb calcium, which bones need to grow and stay healthy.

But now, in the first large randomized controlled study in the United States, funded by the federal government, researchers report that vitamin D pills taken with or without calcium have no effect on bone fracture rates. The results, published Thursday in The New England Journal of Medicine, hold for people with osteoporosis and even those whose blood tests deemed them vitamin D deficient.

These results followed other conclusions from the same study that found no support for a long list of purported benefits of vitamin D supplements.

So, for the millions of Americans who take vitamin D supplements and the labs that do more than 10 million vitamin D tests each year, an editorial published along with the paper has some advice: Stop.

“Providers should stop screening for 25-hydroxyvitamin D levels or recommending vitamin D supplements and people should stop taking vitamin D supplements in order to prevent major diseases or extend life,” wrote Dr. Steven R. Cummings, a research scientist at the California Pacific Medical Center Research Institute, and Dr. Clifford Rosen, a senior scientist at the Maine Medical Research Institute. Dr. Rosen is an editor at The New England Journal of Medicine.

We are accustomed now to the medical community being wrong.  Dramatically wrong and sustainedly wrong.  Still, it is startling that even basic stuff is being revisited and found wrong.

It was an entirely plausible hypothesis that Vitamin D would have the proposed benefits.  But I had assumed that the recommendations were being based on real world research, not mere plausibility.  I was wrong.

Kolada is a little less than clear but it sounds like the existing guidelines were essentially guesses.

Dr. Rosen said those concerns led him and the other members of the National Academy of Medicine’s expert group to set what he called an “arbitrary value” of 20 nanograms per milliliter of blood as the goal for vitamin D levels and to advise people to get 600 to 800 international units of vitamin D supplements to achieve that goal.

Labs in the United States then arbitrarily set 30 nanograms per milliliter as the cutoff point for normal vitamin D levels, a reading so high that almost everyone in the population would be considered vitamin D deficient.

The presumed relationship between vitamin D and parathyroid levels has not held up in subsequent research, Dr. Rosen said. But uncertainty continued, so the National Institutes of Health funded the VITAL trial to get some solid answers about vitamin D’s relationship to health.

From this new research, they now believe that other than for a few people with special conditions, no one should be taking Vitamin D supplements.  

It is wonderful that the research is being conducted to validated long established protocols.  But it remains astonishing to me that the existing protocols were essentially guess work.