When many people think of Vitamin D, they often think of the sun, which is essential to the body's natural production of the vital nutrient.

A deficieny in the "sunshine vitamin," then, isn't something you might expect to find in an athlete who spends a large portion of their day training outside.

And yet, even top-notch athletes—say, the elite college football players at the 2015 NFL Combine—are susceptible to low levels of vitamin D, according to new study presented at the American Academy of Orthopaedic Surgeons Annual Meeting on Thursday.

In the study, researchers analyzed data from 214 players at the Combine. In particular, researchers paid close attention to each player's vitamin D levels and whether or not they had missed any games due to a muscle strain or injury. 

The results? Not only were over half of the athletes (59%) found to have below-normal levels of vitamin D, but 12 of the players with inadequate vitamin D levels also reported missing a game as a result of a muscle-related problem.

"Awareness of the potential for vitamin D inadequacy could lead to early recognition of the problem in certain athletes," says Scott Rodeo, M.D., senior investigator and co-chief emeritus of the Sports Medicine and Shoulder Service at HSS. "This could allow for supplementation to bring levels up to normal and potentially prevent future injury."

But Vitamin D deficiency isn't just linked to muscle strains and injuries—it's also been found to increase a man's risk of erectile dysfuction by 32%. And if that's not a reason to pick up some Vitamin D supplements or get a healthy dose of free sunshine, we don't know what is.