Vitamin D is important for bone health and immune function. Research before the pandemic showed that taking vitamin D can reduce the risk of respiratory infections. Vitamin D may also help regulate the inflammatory response to infection. Naturally, doctors are wondering if taking extra vitamin D might reduce the severity of COVID-19.
One study found that deaths from COVID-19 were more common in countries where people had lower levels of vitamin D. But it’s hard to show that vitamin D is the cause of this. Other factors, like age, obesity, and time spent outdoors might explain why some people both have low vitamin D and are more likely to get very sick with COVID-19. To show that it’s really vitamin D levels that make the difference, doctors will need to do a randomized trial. In this kind of study, doctors would give some people vitamin D (and some people a placebo) and then watch to see if the people taking vitamin D are less likely to get a serious case of COVID-19 later on.
So far, we don’t know for sure whether taking extra vitamin D has any benefits for preventing or treating COVID-19. But even before the pandemic, it was a good idea to make sure you were getting enough vitamin D. Most Americans get vitamin D from spending time outside in the sun, taking a multivitamin, and by eating fortified foods like milk, breakfast cereals, and orange juice. Your doctor can advise you about testing your vitamin D status and whether you might benefit from supplements.
Last update: June 11, 2020 1:45 pm ET
Science review: AGB, ERS, JAB