We keep hearing that Vitamin D is great for our health. So what to make of the U.S. Preventive Services Task Force’s report Tuesday that most of us shouldn’t take Vitamin D supplements, at least not with an eye toward preventing cancer or bone fractures?

The task force issued a draft recommendation based on its review of the scientific literature.  Using the customary plain language of evidence-based science, the report (and its consumer-friendly summary) finds, in short: “For cancer, the Task Force found there isn’t enough information to say whether supplements can prevent cancer. For fractures, the science tells us there is no benefit in taking vitamin D and calcium supplements at low doses to prevent fractures in post-menopausal women. There isn’t enough information to say whether the supplements prevent fractures in men and in premenopausal women, or whether they prevent fractures in postmenopausal women if taken in higher doses.”

In light of those findings, even the relatively small risk of kidney stones that supplementation with 400 International Units (IU) of vitamin D and 1,000 milligrams (MG) of calcium a day poses is viewed as outweighing any potential benefits.

However, the draft recommendation notes that there’s evidence taking Vitamin D supplements can help people over 65 who are at increased risk of falling. Since many fractures result from falls, Vitamin D supplements may be considered to indirectly contribute to reduced fracture risk.

The Institute of Medicine issued a report in November 2010 saying adults should consume 600 IU of Vitamin D (800 IU for those over 70) and 1,000 mg to 1,300 mg of calcium daily.

The USPSTF's draft recommendations are open to public comment through July 10, after which time the draft will be amended, if necessary, and finalized.

Among those who plan to comment are the folks at the Council for Responsible Nutrition, a trade group representing the dietary supplement industry. Taylor Wallace, senior director for scientific and regulatory affairs, says, “As a scientist who recommends Vitamin D to his 91-year-old grandmother, I strongly disagree with this draft recommendation. I don’t think it adds any value for consumers.”

As the Council’s prepared statement notes, the group has serious quibbles with the science on which the draft recommendations are based. Until that’s all sorted out more satisfactorily, Wallace says, CRN’s position is that people taking supplements should continue to take supplements. “If they’re not getting enough from their diet, then supplementing with Vitamin D and calcium is appropriate.”

Wallace suggests that postmenopausal women in particular should “get their Vitamin D levels checked, understand their diet and discuss with a doctor before starting supplements.”