The Institute of Medicine has set new dietary intake levels for vitamin D and calcium for their role in bone health -- but says more research is needed to confirm other possible health benefits associated with these nutrients.
Over the last 10 years, there has been increasing interest in the health benefits of vitamin D. It’s been called the miracle vitamin, as numerous studies suggest the importance of vitamin D goes beyond bone health and may reduce the risk for cancer, heart disease, stroke, diabetes, autoimmune diseases, and more.
Real men get osteoporosis, too.
As many as 2 million American men already have osteoporosis, the bone thinning that makes bones brittle and porous and at likely to fracture. Twelve million men are at risk, and may have early signs of bone loss and low bone density, called osteopenia. But given that four times as many women have osteoporosis, men are less likely to end up with thin bones than women.
Why this lower risk?
"Women live longer, so they're more likely to get osteoporosis," says Paul...
“Everyone wants vitamin D to be the new magic bullet to prevent all kinds of chronic disease, but the evidence is inconsistent and inconclusive at this time to warrant levels beyond our recommendations,” says Harvard’s JoAnn Manson, PhD, MD, and member of the IOM vitamin D and calcium committee.
The committee based its recommendations on a rigorous and thorough review of nearly 1,000 published studies. They were charged to evaluate current data and consider chronic disease implications and outcomes for disease prevention.
New Recommendations for Vitamin D, Calcium
The IOM set the following recommendations for vitamin D:
Ages 1-70: 600 international units (IUs) per day. Older than 71:800 IUs. The IOM previously said 200 IUs was adequate for people aged 50 and younger, 400 IU for people aged 51-70, and 600 IUs for people older than 70.
The tolerable upper limit (UL) is 4000 IUs for ages 9 and above (up from 2000 IU in the IOM's previous guidance).
The IOM's calcium recommendations, based on age, range from 700 to 1300 milligrams (mg) daily with a tolerable upper limit range of 1000-3000 mg.
Experts Respond to Vitamin D Safe Upper Limit
University of Cincinnati bone health expert Nelson Watts, MD applauds the establishing of 4000 IUs as the safe upper limit.
Robert Heaney, MD, a vitamin D researcher and Creighton University professor, agrees but would like to see it even higher.
“I am delighted the upper limit for vitamin D has been doubled to 4000 IUs per day, although this is a conservative level, considering the body of scientific evidence indicating it should be 10,000 IUs," Heaney says. "However, few people need more than 4000 IUs, which will meet the needs of most healthy people, give physicians confidence to recommend supplementation, and allow research at higher vitamin D levels."
In his book, The Vitamin D Solution, Michael Holick, PhD, MD, author and vitamin D researcher, recommends an upper limit of 10,000 IUs for adults and 5,000 IUs for children.
Keep in mind that the upper limit is not the goal for taking supplements or evaluating food labels but is set to establish the safe upper limit.