Evidence lacking for recommendation on routine vitamin D screening, panel says

An independent panel of experts in prevention and evidence-based medicine issued a draft recommendation that vitamin D deficiency is too loosely defined to warrant routine, population-level screening.

by John Tyburski

Copyright © Daily Digest News, KPR Media, LLC. All rights reserved.

First published at Daily Digest News on June 23, 2014

The U.S. Preventive Services Task Force (USPSTF), an independent panel of non-government primary care providers with expertise in evidence-based medicine and prevention, issued a draft recommendation statement on Monday regarding vitamin D deficiency screening. The draft recommendation is based on a draft evidence report issued at the same time and describes the finding that vitamin D deficiency screening in individuals with no symptoms of vitamin D deficiency is not justified.

The USPSTF cited four key reasons for the draft recommendation. First, there is no consensus definition of vitamin D deficiency, nor do experts agree on how much measurable vitamin D should be present in the blood. This complicates the interpretation of research of conditions associated with vitamin D deficiency.

Secondly, although there are numerous testing methods for measuring blood vitamin D levels, the accuracy of these tests is not verified. The USPSTF discovered variation among the testing methods and within testing facilities.

No screening studies have been done to determine the benefits of screening for vitamin D deficiency in adults. Furthermore, no scientific evidence was found supporting treatment for vitamin D deficiency in asymptomatic adults having any risk-reducing effects on cancer, type II diabetes, and other outcomes.

Finally, neither did the USPSTF find studies examining direct harm from screening for vitamin D deficiency. Therefore, while there is no harm in screening, the costs of screening are not offset by any evidence supporting benefits of screening.

Not all health care professionals are supportive of the draft recommendation. “There’s a lot of controversy here,” says task force co-chair Albert Siu, Professor of Geriatrics at the Icahn School of Medicine at Mount Sinai, New York.

Because there is disagreement with how low the levels of vitamin D need to be to diagnose deficiency, the estimates for what proportion of the U.S. population is deficient ranges from 19 to 77 percent.