The Enduring Enigma of Vitamin D Supplementation

By Jonathan Springston, Editor, Relias Media

Should primary care physicians regularly screen all patients for vitamin D deficiency? Like a frustrating answer from a Magic 8-Ball, the U.S. Preventive Services Task Force (USPSTF) this week issued a similarly noncommittal “I statement.” Translation: “Ask again later.”

“We know that vitamin D is an important nutrient for keeping bones healthy and may also have a role in other aspects of good health. However, we need more research on what level of vitamin D people need to stay healthy before we can make a recommendation for or against screening,” USPSTF member Michael Silverstein, MD, MPH, said in a statement.

Is vitamin D a miracle cure, or are some patients so vitamin-deficient that, once administered the vitamins they have been missing, they appear to “magically” improve? Is there such thing as too much vitamin D? What data might be missing that would help inform a more definitive screening recommendation?

“Before we can know if screening for vitamin D deficiency helps prevent negative health outcomes, such as falls, cancer, or heart problems, we need to understand the level of vitamin D that is too low,” USPSTF member John Wong, MD, said in a statement. “Once the ideal level of vitamin D is identified, then research on whether screening for vitamin D deficiency can improve health outcomes will be helpful.”

The COVID-19 pandemic sent everyone scrambling for preventive tools — anything to mitigate risk, including vitamin D. One group of researchers explored possible connections between vitamin D deficiency and risk for testing positive for the coronavirus. Similarly, the creators of the ongoing COVIT-TRIAL theorize vitamin D supplementation might improve the prognosis of COVID-19.

For now, as the USPSTF and others suggest, patients concerned about their vitamin D levels should discuss the matter with their primary care providers.