More work needed to determine groups at risk
While the task force report did not delve into testing or treatment recommendations for symptomatic adults, key established risk factors that may help clinicians identify those who are vitamin D deficient include obesity, receiving little or no UVB light exposure, and older age.
In general, obesity is associated with a 1.3- to 2-fold risk of being vitamin D deficient based on the criteria used, while non-Hispanic Blacks are 2-10 times more likely to be deficient compared with non-Hispanic White patients, the task force noted.
However, the implications of vitamin D deficiency in certain populations can vary. For instance, non-Hispanic Black people, despite having a higher prevalence of lower vitamin D levels compared with White people, in fact, have lower reported rates of fractures.
To address the various issues and gain a better understanding of the complexities of vitamin D deficiency, the task force calls for further research in key areas.
“More research is needed to determine whether total serum 25(OH)D levels are the best measure of vitamin D deficiency and whether the best measure of vitamin D deficiency varies by subgroups defined by race, ethnicity, or sex,” the authors indicated.
Furthermore, “more research is needed to determine the cutoff that defines vitamin D deficiency and whether that cutoff varies by specific clinical outcome or by subgroups defined by race, ethnicity, or sex.”
No support for population-based screening in guidelines
With the lack of conclusive evidence, no organizations currently recommend population-based screening for vitamin D deficiency in asymptomatic patients, and the American Society for Clinical Pathology endorses this stance.
The Endocrine Society and the American Association of Clinical Endocrinologists meanwhile do recommend screening for vitamin D deficiency in patients considered at risk.
Data show there was as much as an 80-fold increase in Medicare reimbursement volumes for vitamin D testing among clinicians from 2000 to 2010; however, that rate may have leveled off after the National Academy of Medicine reported on set deficiency levels, said Sherri-Ann M. Burnett-Bowie, MD, MPH, Dr. Cappola’s editorial coauthor.
Dr. Burnett-Bowie noted that she regularly tests her patients’ vitamin D levels, however most of her patients have osteoporosis or fractures.
“I do screen them for vitamin D deficiency since optimizing their vitamin D will improve calcium absorption, which is important for treating their osteoporosis,” Dr. Burnett-Bowie, of the endocrine division, department of medicine, Massachusetts General Hospital, Boston, said in an interview.
In terms of broader testing of asymptomatic patients in the general population, however, any changes in screening will likely be contingent on developments in the effects of treatment, she said.
“Given the challenge in finding benefits of vitamin D supplementation in those who are deficient, it will likely be more challenging to find benefits from wider screening,” she concluded.
The USPSTF and editorialists reported having no relevant financial relationships.
A version of this article first appeared on Medscape.com.