Experts Unable to Recommend Screening Most Adults for Vitamin D Deficiency

The benefits of screening for vitamin D deficiency in asymptomatic adults are still unclear according to a recent recommendation statement issued by the U.S. Preventive Services Task Force (USPSTF). USPSTF's recommendation remains unchanged since the last update in 2014.

The statement, which highlights a systematic review on screening for vitamin D deficiency, concludes that there is still insufficient evidence to prove that routine vitamin D screening benefits community-dwelling, non-pregnant, asymptomatic adults and therefore does not recommend it.  

“This is a call for further research to determine a screening recommendation,” John B. Wong, MD, USPSTF member and chief scientific officer of the department of medicine at Tufts Medical Center, tells Verywell. “We could not find studies that looked at vitamin D screenings that included a follow-up to see if any important patient health outcomes had improved.”

Currently, there is no standard guideline for general vitamin D screening of patients not at risk for a deficiency. The statement reported that the American Academy of Family Physicians agrees there is insufficient evidence to recommend screening the general population, while the American Association of Clinical Endocrinologists recommends only screening people at high risk of vitamin D deficiency. 

Vitamin D Research Gaps

Data on laboratory test trends show that testing for vitamin D levels substantially increased over the years despite the lack of research and evidence surrounding its positive health outcomes.

USPSTF reports that vitamin D research gaps leave questions to be answered like:

• Is the total serum 25-hydroxyvitamin D blood test the best measure of vitamin D?
• Does the best measure of vitamin D vary by race, ethnicity, or sex?
• What is the cutoff serum level that defines a vitamin D deficiency? Is this different for different groups?

USPSTF suggests that when it's clearer what vitamin D deficiency is, it will be helpful to have studies to evaluate the benefits and harms of screening the general public.

Because sufficient vitamin D levels can vary from person to person, routine screening can potentially overdiagnose people who don’t need treatment, or underdiagnose and miss the opportunity to correct a vitamin D deficiency in someone who could benefit from treatment. 

Who Is At Risk for Deficiency?

While the Endocrine Society does not recommend screening asymptomatic low-risk individuals, they do recommend routinely testing people who are at high risk for vitamin D deficiency. 

People at high risk for vitamin D deficiency include:

• Breastfed infants
• Older adults
• People with dark skin
• People with limited sun exposure
• People with conditions that limit fat absorption 
• People with obesity or who have undergone gastric bypass surgery
• People who take certain medications

On average, 97.5% of the population will be vitamin D sufficient at the recommended 20 ng/ml, however, reaching that threshold can be a challenge since very few foods contain vitamin D and sun exposure is dependent on weather, location, and time of day. 

“Many people can’t get adequate vitamin D levels naturally,” Michael Holick, MD, director of the Vitamin D Skin and Bone Research Laboratory at the Boston University School of Medicine, tells Verywell. “Because of this, I would recommend people use supplements to help meet their vitamin D needs.”

How to Boost Your Vitamin D Levels

You can boost your vitamin D levels naturally through sun exposure as well as in foods. Some foods that are good sources of vitamin D include:

• Salmon
• Milk fortified with vitamin D
• Soy, almond, and oat milk
• Eggs
• Cod liver oil
• Orange juice fortified with vitamin D
• Dairy products made from milk
• Beef, pork, chicken

Talk with your doctor if you are at high risk for vitamin D deficiency, or have a medical condition that interferes with your absorption of vitamin D. They can help you find the correct supplement dosage that will keep you at optimal health.