Need Vitamin D Supplements? Depends Which Newspaper You Read
Yesterday’s Times carried on its front page an article by Gina Kolata headlined “Extra vitamin D and Calcium Aren’t Necessary, Report Says.” Relevant excerpts:
The very high levels of vitamin D that are often recommended by doctors and testing laboratories – and can be achieved only by taking supplements – are unnecessary and could be harmful, an expert committee says.
“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.
But the craze might not be quelled if enough people read the same day’s Wall Street Journal. The headline reads “Triple That vitamin D Intake, Panel Prescribes.” Relevant excerpts, from the article by Melinda Beck:
A long-awaited report from the Institute of Medicine to be released Tuesday triples the recommended amount of vitamin D most Americans should take every day to 600 international units from 200 IUs set in 1997.
That’s far lower than many doctors and major medical groups have been advocating-and it could dampen some of the enthusiasm that’s been building for the sunshine vitamin in recent years.
There is not as much contradiction in the two articles as the headlines might connote — but still: a lot of people read only the headlines of a story like this and then carry around that new conventional wisdom forever. (Also worth noting: neither article took into account the fact that different people in different climates have different vitamin D intake levels via the sun, which has a strong effect on how much supplemental D someone might need.)
Yesterday’s Marketplace report on the vitamin D story, meanwhile, sounds a proper note of caution. Granted, it comes from a spokesperson for a dietary-supplement trade group, Judy Blatman, but still:
We really would urge that consumers certainly read the media reports but don’t just read the headlines, read the entire thing.
Also worth remembering: a lot of readers blame journalists for misleading headlines. But almost always, at least with mainstream media, it isn’t the writer of an article but rather an editor who writes the headline.
P.S.: There’s also a Freakonomics Radio segment on yesterday’s Marketplace, about whether more expensive wines taste better than cheaper ones. You’ll hear from wine researchers Robin Goldstein and Orley Ashenfelter — and you’ll get wine-buying advice from Steve Levitt, of all people. We’re expanding the wine story into a podcast, so keep your ears open.