Vitamin D has been the subject of great debate in recent years, with most experts agreeing we’re dangerously deficient but little consensus regarding just how much we need—or how we should be getting it. According to the most recent National Health and Nutrition Examination Survey, nearly half of all U.S. adults are vitamin D deficient, and even more have levels that are lower than is ideal.
We need vitamin D. Studies have shown that vitamin D—which is, in fact, not a vitamin but rather a hormone—may help prevent a number of serious illnesses, including multiple sclerosis, certain types of cancer, and cardiovascular disease. What’s more, it’s been believed to be an important factor in ensuring healthy bones, since vitamin D aids in the body’s absorption of calcium.
Our bodies produce all the vitamin D we need through the sun’s UVB rays most—though not all—of which a decent sunscreen filters out. And though certain foods are sources of vitamin D—including fatty fish, eggs and fortified dairy—most experts agree that it’s difficult to get adequate vitamin D from food alone. And so until recently, the smartest move, experts have said, was to get a little vitamin D from the sun and the rest from supplements. (The most recent recommendation by the Institute of Medicine put the amount of vitamin D we need per day at 600 IU. for those ages 1 to 70, and 800 IU. for those over 70, up from the previous recommendation of 200 to 600 IU.)
Last week, however, the U.S. Preventative Series Task Force—an independent panel of experts in prevention and primary care appointed by the Department of Health and Human Services—issued a statement advising healthy post-menopausal women not to take vitamin D supplements as a preventative measure for bone health. That’s because most supplement doses are too low to prevent fractures, aren’t actually proven to prevent cancer, and may cause painful kidney stones. The group also stated that there’s no reason pre-menopausal women should take supplements, either. They based their recommendations on 137 studies, including randomized controlled trials.“Vitamin D and calcium are part of a healthy diet,” task force member Dr. Kirsten Bibbins-Domingo, an associate professor of medicine at the University of California in San Francisco, told the New York Times. “Most people can achieve sufficient doses with a healthy diet.”
Kripalu Healthy Living nutrition experts, however, warn against cutting out vitamin D supplements altogether. “We feel that it’s good if women get the message to scale back on supplements—calcium in particular—but we do think that very many people have low serum vitamin D, and may benefit from a supplement,” says Annie Kay, MS, RD, RYT, a faculty member in Kripalu’s Healthy Living programs and the former director of the osteoporosis awareness program at the Massachusetts Department of Public Health. “Anyone at risk for a low serum vitamin D—which includes people with darker skin tones, babies and the elderly, and those who live in northern climates including most of the United States, as well as people with autoimmune or other chronic conditions —should be tested, because low levels of vitamin D can have broad and variant ramifications for health.” Symptoms of low levels of vitamin D include depression, anxiety, memory loss, and fatigue; if you think you may be deficient, ask your physician to test your levels; according to the National Institutes of Health, the most accurate way to measure how much vitamin D is in your body is with the 25-hydroxy vitamin D blood test. Despite the recent rulings, vitamin D is still critical to good health. Says Annie, “We’ve seen repletion of low vitamin D make big differences in people’s lives.”