Seven years after concluding that there was insufficient evidence to recommend screening for vitamin D deficiency in the general population, the United States Preventive Services Task Force (USPSTF) reviewed the issue – and came to the same conclusion.
In general, “current evidence is inadequate to determine whether screening and treatment of low asymptomatic levels of 25 (OH) D improve clinical outcomes in adults living in the community,” the Task Force concludes in its statement, recommending an “I” for failure.
The statement was published online on April 13 in JAMA.
In the absence of screening recommendations, physicians may be advised to focus instead on diet and supplements for those considered at risk, said Anne R. Cappola, MD, of the Perelman School of Medicine at the University of Pennsylvania, Philadelphia.
“Instead of focusing on screening the general population for vitamin D deficiency, let’s focus on ensuring that everyone consumes the recommended daily dose based on age of vitamin D instead,” said Cappola, a co-author of the accompanying editorial. . Medscape medical news.
No study has directly evaluated the benefits of screening
The most recent USPSTF recommendation is based on a systematic review of the benefits and harms of screening and early treatment for vitamin D deficiency in asymptomatic, unloaded adults 18 years of age or older in the primary setting with no signs or symptoms of deficiency. .
The review did not find studies that directly evaluate the benefits of vitamin D deficiency screening.
However, 26 randomized clinical trials and one nested case-control study evaluated the effectiveness of treating vitamin D deficiency with supplementation.
And while observational studies have linked lower levels of vitamin D to a multitude of conditions and risks, evidence of any benefit has been inconsistent, with none identified for most major outcomes in asymptomatic adults – the focus of the task force’s recommendation.
“Among asymptomatic populations living in the community with low vitamin D levels, evidence suggests that vitamin D treatment has no effect on mortality or the incidence of fractures, falls, depression, diabetes, cardiovascular disease, cancer or adverse events.” reviewing authors’ stress.
“The evidence is inconclusive about the effect of treatment on physical functioning and infection.”
1 in 4 are Vitamin D deficiency
Regarding the additional question about the potential harms of vitamin D screening in asymptomatic individuals, a key concern is the potential for misclassification and over- or under-diagnosis due to inconsistent cuts and variability of different screening tests, concludes the analysis.
However, with the rare exception of vitamin D toxicity from supplementation well above sufficient levels, treatment with vitamin D supplementation seems relatively safe.
With a lack of consensus even on the baseline for vitamin D deficiency, the National Academy of Medicine established in 2011 that hydroxyvitamin D (25[OH]D) levels below 20 ng / ml are deficient for bone health, without evidence of different thresholds for any other state of health.
Based on this limit, the National Health and Nutrition Examination Study (NHANES) reported in 2014 that 25% of the US population over 1 year of age was deficient in vitamin D, with 18% of the population having 25 (OH) D levels. 12 to 19 ng / ml and 5% with very low levels (<12 ng / ml).
More work is needed to determine the groups at risk
While the Task Force report did not analyze test or treatment recommendations for symptomatic adults, key established risk factors that can help clinicians identify those with vitamin D deficiency include obesity, who receive little or no exposure to UVB light, and older age.
In general, obesity is associated with a 1.3 to 2-fold risk of vitamin D deficiency based on the criteria used, while non-Hispanic blacks are 2 to 10 times more likely to be deficient compared to with non-Hispanic white patients, Notes to the Working Group.
However, the implications of vitamin D deficiency in some populations may vary. For example, non-Hispanic people of color, despite having a higher prevalence of lower vitamin D levels compared to white people, actually reported lower fracture rates.
In order to address the various issues and gain a better understanding of the complexities of vitamin D deficiency, the Task Force calls for further research into key areas.
“More research is needed to determine whether total levels of 25 serum (OH) D are the best measure of vitamin D deficiency and whether the best measure of vitamin D deficiency varies by race-defined subgroup. , ethnicity or sex “, they indicate.
In addition, “more research is needed to determine the limit that defines vitamin D deficiency and whether this limit varies depending on the specific clinical outcome or subgroups defined by race, ethnicity or sex.”
There is no support for population-based screening in the Guides
Due to the lack of conclusive evidence, no organization currently recommends population-based screening for vitamin D deficiency in asymptomatic patients, and the American Society of Clinical Pathology supports this position.
Meanwhile, the Endocrine Society and the American Association of Clinical Endocrinologists (AACE) recommend screening for vitamin D deficiency in patients considered at risk.
The data show that there was an 80-fold increase in Medicare reimbursement volumes for vitamin D testing among clinicians from 2000 to 2010; however, this rate would have leveled off after the National Academy of Medicine reported the established levels of deficiency, said Sherri-Ann M. Burnett-Bowie, MD, MPH, co-author of Cappola.
Burnett-Bowie said she regularly tests patients’ vitamin D levels, but most of her patients have osteoporosis or fractures.
“I find them for vitamin D deficiency because optimizing vitamin D will improve calcium absorption, which is important for treating their osteoporosis,” said Burnett-Bowie of the Endocrine Division, Department of Medicine, Massachusetts General Hospital in Boston. Medscape medical news.
Regarding the wider testing of asymptomatic patients in the general population, however, any change in screening will likely be conditioned by the evolution of the effects of treatment, she said.
“Given the challenge of finding the benefits of vitamin D supplementation in those with deficiencies, it will probably be more difficult to find benefits from wider screening,” she concluded.
USPSTF and editorialists did not report relevant financial reports.
JAMA. Published on April 13, 2021. Statement, Review, Editorial
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