Researchers at Johns Hopkins University in the US have found that high doses of vitamin D aren’t only unhelpful, they may also be harmful.
Healthy adults have been "bombarded" by stories in the media on how low vitamin D levels can increase risks of everything from hypertension to hardening of the arteries, the researchers said.
"Healthy people have been popping these pills, but they should not continue taking vitamin D supplements unchecked," advised study leader Dr. Muhammad Amer, an assistant professor in the Division of General Internal Medicine at the Johns Hopkins University School of Medicine. "At a certain point, more vitamin D no longer confers any survival benefit, so taking these expensive supplements is at best a waste of money."
To reach their findings, Amer and his team analyzed data from more than 10,000 participants in the National Health and Nutrition Examination Survey from 2001 to 2004. The findings, announced May 1, appear online in the American Journal of Medicine.
Amer does stress however that some groups of people, such as the elderly and postmenopausal women, do benefit from high levels of vitamin D under a physician’s supervision.
People should consult with their doctors, Amer said, before starting vitamin D supplements and have their blood levels checked. "Most healthy people are unlikely to find that supplementation prevents cardiovascular diseases or extends their lives," he added, and there is no consensus among doctors on what is the right level of vitamin D in the blood for healthy people.
Access the study: http://www.amjmed.com/article/S0002-9343%2813%2900084-3/abstract
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