Seven years after concluding that the evidence was insufficient to recommend screening for vitamin D deficiency in the general population, the United States Preventive Services Task Force (USPSTF) re-examined the matter – and came to the same conclusion.
Overall, “the current evidence is not sufficient to determine whether screening for and treatment of asymptomatic low 25 (OH) D levels improves clinical outcomes in adults living at home,” the Task Force concludes in its statement, in which it “I “recommends for insufficient.
The statement was published online April 13 in JAMA
In the absence of screening recommendations, doctors are best advised to focus on diet and supplementation instead for those considered at risk, said Anne R. Cappola, MD, of the Perelman School of Medicine at the University of Pennsylvania, Philadelphia.
“Rather than asking the question of screening the general population for vitamin D deficiency, let’s focus on making sure everyone is getting their age-based recommended daily intake of vitamin D instead,” said Cappola, a co-author. author of the accompanying editorial. Medscape Medical News
No studies have directly evaluated the benefits of screening
The latest USPSTF recommendation is based on a systematic review of the benefits and harms of screening and early treatment of vitamin D deficiency in asymptomatic, home-living non-pregnant adults aged 18 years or older in primary care, with no signs or symptoms of a shortage.
The review did not find any studies directly evaluating the benefits of vitamin D deficiency screening.
However, 26 randomized clinical trials and one nested case-control study evaluated the effectiveness of vitamin D deficiency treatment with supplementation.
And while observational studies have associated lower vitamin D levels with a wide range of conditions and risks, the evidence of some benefit has been inconsistent, with none identified for most of the key outcomes in asymptomatic adults – the focus of the recommendation. Task Force.
“Among asymptomatic, home-living populations with low vitamin D levels, the evidence suggests that vitamin D treatment has no effect on mortality or incidence of fractures, falls, depression, diabetes, cardiovascular disease, cancer or adverse events,” the review authors emphasize.
“The evidence is inconclusive about the effect of treatment on physical function and infection.”
1 in 4 ares Vitamin D deficiency
In terms of the further question of the potential drawbacks of vitamin D screening of asymptomatic individuals, a major concern is the potential for misclassification and over- or underdiagnosis due to inconsistent cut-offs and variability of different screening tests, the review concludes. .
With the rare exception of vitamin D toxicity from supplementation well above adequate levels, vitamin D supplementation treatment appears to be relatively safe.
With a lack of consensus, even on the baseline for vitamin D deficiency, the National Academy of Medicine determined in 2011 that hydroxyvitamin D (25[OH]D) Levels below 20 ng / ml are inadequate for bone health, with no indication of other thresholds for any other health condition.
Based on that boundary, the National Health and Nutrition Examination Survey (NHANES) reported in 2014 that 25% of the U.S. population over 1 year of age had vitamin D deficiency, while 18% of the population had 25 (OH) D levels of 12. up to 19 ng / ml and 5% with very low levels (<12 ng / ml).
More work is needed to determine risk groups
While the Task Force’s report did not address testing or treatment recommendations for symptomatic adults, the main risk factors identified that can help clinicians identify those who are vitamin D deficient, including obesity, are little or no exposure to UVB. light and older age.
Overall, obesity is associated with a 1.3 to 2 times greater 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 non-Hispanic white patients, Task Force Notes.
However, the consequences of vitamin D deficiency in certain populations can vary. For example, non-Hispanic black people, despite a higher prevalence of lower vitamin D levels compared to white people, actually have lower reported fractures.
To address the various issues and gain a better understanding of the complexity of vitamin D deficiency, the Task Force is calling 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 subgroup defined by race, ethnicity, or gender” , they indicate.
In addition, “more research is needed to determine the cut-off that defines vitamin D deficiency and whether that cut-off varies by specific clinical outcome or by subgroups determined by race, ethnicity, or gender.”
No support for population screening in guidelines
In the absence of conclusive evidence, no organizations are currently recommending a screening program for vitamin D deficiency in asymptomatic patients, and the American Society for Clinical Pathology endorses this view.
The Endocrine Society and the American Association of Clinical Endocrinologists (AACE), meanwhile, recommend screening for vitamin D deficiency in patients at risk.
Data show that between 2000 and 2010 there was an 80-fold increase in Medicare reimbursement volumes for vitamin D testing among clinicians; However, that percentage may have leveled off after the National Academy of Medicine reported on established deficit levels, said Sherri-Ann M. Burnett-Bowie, MD, MPH, Cappola’s editorial co-author.
Burnett-Bowie noted that she regularly tests her patients’ vitamin D levels, but most of her patients have osteoporosis or fractures.
“I screen them for vitamin D deficiency, as optimizing their vitamin D will improve calcium absorption, which is important for treating their osteoporosis,” Burnett-Bowie of the Endocrine Division, Department of Medicine, Massachusetts General Hospital told me. Boston. Medscape Medical News
In terms of wider testing of asymptomatic patients in the general population, any changes in screening will likely depend on developments in the effects of the treatment, she said.
“Given the challenge of finding the benefits of vitamin D supplementation in deficient people, it will likely be more challenging to find benefits from broader screening,” she concluded.
The USPSTF and editors have not reported any relevant financial relationships.
JAMA. Published April 13, 2021. Statement, Review, Editorial
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