Nearly 60 percent of college football players have low levels of vitamin D, a new study suggests.

That means they face a significantly higher risk for muscle strain and injury, the researchers said.

"We were interested in vitamin D in this population because it's been shown to play an important role in muscle function and strength, which is critical to the high-performance athlete," said study author Dr. Brian Rebolledo. He's an orthopedic surgeon at the Scripps Clinic in La Jolla, Calif.

"Most of the past research into the harmful effects of low vitamin D has focused on the elderly, but relatively few studies have examined this association in the elite athlete," Rebolledo said in a Scripps news release. "This study suggests that monitoring and treating low vitamin D may potentially be a simple way to help prevent certain muscle injuries."

Rebolledo noted, though, that "additional research needs to be done to see if boosting vitamin D levels leads to improved muscle function and fewer injuries."

The findings stem from an analysis that reviewed data on 214 college football players who'd taken part in the National Football League's so-called "scouting combine" in 2015.

Data included the players' vitamin D levels, injury history and number of games missed because of a lower extremity muscle strain or core muscle injury.

The researchers determined that 59 percent of the players had below-normal vitamin D levels. More than half of those who did—56 percent—had sustained a relevant strain or injury during play.

That figure went up to 73 percent among those with "severely deficient" vitamin D levels.

By comparison, similar strains and injuries affected just 40 percent of players with normal vitamin D levels.

And among the 14 players who had missed at least one game as a result of such targeted strains or injuries, 86 percent had low vitamin D levels.

That said, vitamin D deficiency was not spread equally among all players. For instance, 70 percent of black players had low vitamin D, compared with 13 percent of white players.

No marked differences were found based on the positions the young men played on the field.

The research team noted that vitamin D deficiency is not uncommon, affecting nearly 42 percent of American adults. It results mostly from poor diet and not enough sun exposure.

The study was published online recently in Arthroscopy: The Journal of Arthroscopic and Related Surgery.

More information: Information on vitamin D is available from the U.S. Office of Dietary Supplements.

Fitbit Coach, the company’s connected personal training app, has come to Microsoft’s Xbox One videogame console and other Windows 10 PCs, Fitbit announced in a recent blog post. The service — which costs $39.99 annually — allows customers to follow guided audio and video workouts in their home with additional features provided by their Fitbit wearables.

Fitbit Coach is a rebranded version of the FitStar service, which Fitbit acquired in 2015 for roughly $25 million. First launched in October, the premium version of the app gives home users a regularly updated selection of video workouts with various fitness goals.

The service also comes with a customizable selection of music courtesy of feed.fm, while its mobile version includes dozens of running and walking audio workouts for use during an outdoor or treadmill session. The free version of the app is limited to a single personalized program alongside a selection of audio and video workout programs.

By connecting a Fitbit tracker or smartwatch that includes continuous heart rate monitoring, the home workout app will also display your heart rate on the screen throughout a user’s workout session, according to the company. Further, the app offers regular device wearers specific workout session recommendations personalized to their recorded daily activities.

Continued support for Fitbit’s software offerings shouldn’t be too a big surprise for those following the wearable producer. When the product first launched last year, Jon Oakes, VP of product at Fitbit, said that the company had “plans to open the platform to second and third party partners in the future.”

Additionally, during a November earnings call, CEO James Park highlighted a 75 percent year-over-year increase in in the app’s premium customers during Q3, and the fitness platform’s ability “to deepen user engagement by leveraging data” while offering workout guidance.

“Not only does this data allow us to deliver personalized health and fitness coaching and guidance, it also has the potential to help us detect more serious health conditions, which affect hundreds of millions of people worldwide and are the source of huge healthcare costs,” he said during the call. “We believe our data gives our advanced research team, comprised of scientists, doctors and health care experts, a clear advantage to develop algorithms and advanced sensors to detect these health conditions on a scale not previously available.”