The Task Force had previously found vitamin D supplements effective in preventing falls in adults 65 years or older, who are at an increased risk for falls. It stands by that recommendation with “high certainty” of a “moderate to substantial” outcome.

“We know that vitamin D is an essential part of a healthy diet – and other groups have been clear that vitamin D at 800 IU is a dose that is essential, and most people can achieve with diet,” says Dr. Bibbins-Domingo. “What we are talking about is supplements, and what we can say is, at 400 IU, it is not helpful. And at higher doses all we can say is there is insufficient evidence.”

“This is like [the soap opera] As The World Turns,” says Mitchell Freedman, DO, physical medicine specialist at the Rothman Institute in Philadelphia, referring to the back-and-forth claims about calcium and vitamin D. “Part of the issue is, nobody knows.”

For example, other recent studies have linked calcium supplementation to a bigger risk – heart attacks.

There’s no question calcium and vitamin D are necessary for healthy bones and good health, but the draft recommendations could just fuel the position that it’s best to get them through a healthy diet.

“I recommend that it is ideal for postmenopausal women to consume 1,200 mg of calcium from calcium-rich food sources. This is the Recommended Dietary Allowance for calcium included in the Institute of Medicine 2011 report,” says Meryl LeBoff, MD, director of the Bone Density Unit at Brigham and Women’s Hospital in Boston and a professor of medicine at Harvard Medical School.

“If a woman’s diet does not include this amount of calcium, I would add a calcium supplement – after calculating her calcium intake from food sources – because it’s important not to take too much calcium from diet and supplements.”

As for vitamin D, Dr. LeBoff says it’s often necessary to supplement – and points to results from the National Health and Nutrition Examination Survey, or NHANES – a large, ongoing, government-sponsored study looking at the health of Americans. “The NHANES data show that about one-third of the population has vitamin D deficiency, and there are many individuals in the population at high risk for vitamin D deficiency,” she says.

In the meantime, if you are unclear about whether you should be taking supplemental vitamin D and/or calcium, ask your doctor. “The Task Force is pretty conservative, because they are recommending things from the population perspective. But it doesn’t preclude anyone from talking with their physician about their personal risks,” says Miller. He notes, for example, that anyone who is taking medications for osteoporosis needs to take make sure they are getting adequate vitamin D and calcium in order to build bones.