You know vitamin D can help you fend off osteoporosis and falls.

But if recent headlines have you thinking you might want to pop some more of it to avoid a severe case of COVID-19, know that researchers are still sorting out how, exactly, a deficiency in the vitamin may make you more vulnerable to the disease’s more serious symptoms.

For now, experts such as those publishing in a recent BMJ Nutrition, Prevention & Health report don’t recommend you boost your intake to avoid COVID-19 complications, accordingto a story on AARP.org.

As they wrote, “There is no strong scientific evidence to show that very high intakes (i.e., mega supplements) of vitamin D will be beneficial in preventing or treating COVID-19.”

What’s more, there are risks involved with downing excessive doses of the vitamin — particularly for those with health conditions such as kidney disease.

While researchers continue to research a possible link between COVID-19 and vitamin D levels, here’s what we do know about this bone-building (and muscle-strengthening!) nutrient — and how to know if you need a supplement to get the recommended daily allowance.

By now, most of us know that vitamin D plays an important role in promoting the absorption of bone-fortifying calcium.

But in this case, more is not necessarily more: “If your vitamin D level is sufficient, it doesn’t seem like you get a lot of benefit from supplementation,” says Karl Nadolsky, , a clinical endocrinologist and clinical assistant professor of medicine at Michigan State University.

Those of us who are deficient in the vitamin — an oft-cited study puts the number at over 40 percent of the U.S. population — may reap benefits from raising their levels.

“We know that having very low levels of vitamin D is bad for a lot of things, especially bones,” Nadolsky says.

“It’s certainly associated with a lot of things, like type 2 diabetes, cardiovascular health, even early death.” Vitamin D deficiencies have also been linked to breast cancer. Problem is, it’s hard to tell if a deficiency of this type is a consequence of ill health, or its cause.

There is some encouraging research that suggests that boosting your level of D and bringing it back to safe levels may improve health outlooks.

A recent study published in Seminars in Cancer Biology, for instance, suggests “a good vitamin D status” may be beneficial both in cancer prevention and in the prognosis of several cancers.

And organizations such as the National Osteoporosis Foundation consider both vitamin D and calcium to be essential to maintaining dense, strong bones as you age.

And although a clear connection with COVID-19 has not been found, a 2017 study involving more than 11,000 participants found evidence that vitamin D may help protect against upper respiratory tract infections.