USPSTF: Not Enough Evidence for Vitamin D Screening
Key clinical point: The USPSTF makes no recommendation for or against screening and treating asymptomatic adults for vitamin D deficiency, because the evidence regarding the benefits and harms is insufficient.
Major finding: Testing of vitamin D levels has increased markedly, with one national survey showing the annual rate of outpatient visits with a diagnosis code for vitamin D deficiency more than tripled between 2008 and 2010, and a 2009 survey of clinical laboratories reporting that the testing increased by at least half in the space of just 1 year.
Data source: A detailed review of the evidence and an expert consensus regarding screening asymptomatic adults for vitamin D deficiency to prevent fractures, cancer, CVD, and other adverse outcomes.
Disclosures: The USPSTF is an independent, voluntary group supported by the U.S. Agency for Healthcare Research and Quality to improve Americans’ health by making recommendations concerning preventive services such as screenings and medications. Dr. LeFevre and his associates reported having no relevant financial disclosures.
FROM ANNALS OF INTERNAL MEDICINE
Symptomatic vitamin D deficiency is known to affect health adversely, as is asymptomatic vitamin D deficiency in certain patient populations. But the evidence that deficiency contributes to adverse health outcomes in asymptomatic adults is inadequate. The evidence that screening for such deficiency and treating “low” vitamin D levels prevents adverse outcomes or simply improves general health also is inadequate, Dr. LeFevre and his associates said.
Similarly, no studies to date have directly examined possible harms of screening for and treating vitamin D deficiency. Although there are concerns that vitamin D supplements may lead to hypercalcemia, kidney stones, or gastrointestinal symptoms, there is no evidence of such effects in the asymptomatic patient population.
The USPSTF concluded that the harms of screening for and treating vitamin D deficiency are likely “small to none,” but it still is not possible to determine whether the benefits outweigh even that small amount of harm.
At present, no national primary care professional organization recommends screening of the general adult population for vitamin D deficiency. The American Academy of Family Physicians, the Endocrine Society, the American College of Obstetricians and Gynecologists, the American Geriatrics Society, and the National Osteoporosis Foundation all recommend screening for patients at risk for fractures or falls only. The Institute of Medicine has no formal guidelines regarding vitamin D screening, Dr. LeFevre and his associates noted.
The USPSTF summary report and the review of the evidence are available at www.uspreventiveservicestaskforce.org.
