Recent studies say taking extra amounts of the nutrient may not be a boon for every body
By Laura Beil
In the supplement world, vitamin D is a bit like a Kardashian. Its fame seemed to come out of nowhere about a decade ago, garnering so much press so fast that it’s hard to remember a time when people weren’t talking about it.
Vitamin D had long been known for protecting bones, but its star began to rise in the early 2000s after researchers made connections hinting that vitamin D was good for a lot more than our skeletons. It appeared to help protect against a lengthy list of ailments, including multiple sclerosis, asthma, depression, heart disease and cancer. The vitamin also was said to improve athletic performance.
Organizations like the Vitamin D Council — the 2003 brainchild of a psychiatrist who became a vitamin D enthusiast — began to actively promote the benefits to the public and to physicians, while selling test kits for vitamin D blood levels. Doctors checked for it; patients demanded testing. Researchers latched on.
But with more research comes more scrutiny, and most recently, a series of seemingly tarnishing findings. On November 10, the New England Journal of Medicine published the largest study so far to test vitamin D supplements’ protection against cancer and heart disease. The results were generally interpreted as inconclusive at best and disappointing at worst. One 2017 review of the evidence for cardiovascular benefits concluded that studies of people taking vitamin D “have failed to show clear improvements in blood pressure, insulin sensitivity or lipid parameters.” . .