Pros and cons of vitamin D screening

- Kenny Lin, MD

The U.S. Preventive Services Task Force recently announced its intent to review the evidence and issue recommendations about screening for vitamin D deficiency, after finding insufficient evidence to recommend routine supplementation for the prevention of fractures in adults. According to a 2009 review published in American Family Physician, up to half of U.S. adults 65 years and older have inadequate vitamin D levels, which places them at increased risk of falls and fractures. Two editorials in the April 15th issue of AFP debate the pros and cons of screening for vitamin D deficiency in asymptomatic persons.

Dr. Leigh Eck makes the case for targeted screening for vitamin D deficiency in at-risk populations, which include, but are not limited to, persons with malabsorption syndromes, persons with chronic kidney disease, pregnant and lactating women, and older persons with a history of falls. "Most of these factors put patients at risk of osteoporosis," Dr. Eck argues. "Given the role of vitamin D in bone mineralization, patients who are at risk of or who have osteoporosis should be considered as candidates for vitamin D screening."

On the other hand, Dr. Colin Kopes-Kerr identifies several problems with measurement of serum vitamin D levels in asymptomatic persons, regardless of risk level: lack of test standardization; disagreement about what constitutes a "normal" vitamin D level; unclear treatment implications; and uncertain cost-effectiveness. Finally, he points out, "No study has demonstrated that measurement of serum 25-hydroxyvitamin D levels offers outcome benefits over clinical assessment alone."

The Endocrine Society recommends against population-based screening for vitamin D deficiency, and the American Society for Clinical Pathology included this screening test in its list of "Five Things Physicians and Patients Should Question" for the Choosing Wisely campaign.