By Nancy Shute, NPR
It’s not easy being a wonder vitamin these days. Just when it looks like you’re the solution to every health problem, some doctors come along and burst your bubble. Now it’s happening to vitamin D.
The supplement has been widely promoted to prevent osteoporosis and fight a host of other ills. But recent studies haven’t found much benefit, for bones or for general health.
This latest review looks at 23 randomized controlled trials involving more than 4,000 people to study vitamin D’s effect on bones. Vitamin D, which is converted into a hormone by the body, makes it easier for us absorb calcium in the intestines. So it’s easy to presume that more “D” would lead to stronger bones.
But this review found that for middle-aged people, taking vitamin D supplements for two years didn’t affect bone mineral density in the spine, hip, arm bone and skeleton overall. They did find increased bone density in the neck of the femur bone, where it often breaks in the elderly. The review also found no relation between bone density and taking calcium supplements, people’s overall vitamin D levels, length of treatment or age. Continue reading