New study shows muscle injuries in athletes may be caused by low vitamin D levels

LA JOLLA (KUSI) — Low levels of vitamin D could be a factor in muscle injuries suffered by athletes, according to a study authored by an orthopedic surgeon at Scripps Clinic in La Jolla that was released Thursday.

In the study published online by Arthroscopy: The Journal of Arthroscopic and Related Surgery, Dr. Brian Rebolledo said 56 percent of football players that were examined who had low vitamin D experienced a lower extremity muscle strain or core muscle injury while playing in college, which jumped to 73 percent if severely deficient.

Among players with normal vitamin D levels, 40 percent had experienced such injuries, which he called a statistically significant difference between the groups.

Rebolledo’s team analyzed data that was collected from 214 players at the 2015 NFL Combine, where scouts evaluate top prospects coming out of college. The researchers recorded their vitamin D levels, age, position, race, injury history and whether they had missed any college games due to a lower extremity muscle strain or core muscle injury.

“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,” Rebolledo said. “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.”

He also found that of the 14 study participants who missed at least one collegiate football game due to a muscle injury to a lower extremity or core region, 86 percent were found to have significantly low levels of vitamin D.

Also, 70 percent of black athletes had low levels of vitamin D, compared to 13 percent of whites. There were no meaningful differences in vitamin D levels between skill position players like quarterbacks, running backs, receivers, defensive backs and kickers or linemen, linebackers and tight ends.

The average age of study participants was 22.

“This study suggests that monitoring and treating low vitamin D may potentially be a simple way to help prevent certain muscle injuries,” Rebolledo said. “Additional research needs to be done to see if boosting vitamin D levels leads to improved muscle function and fewer injuries.”

He recommended that all adults have their doctor check their vitamin D levels, whether they participate in athletics or just walk their dog around the block.

Low vitamin D may result from poor dietary intake, lack of adequate sunlight exposure or poor absorption due to issues like inflammatory bowel disease and celiac disease.

The two main ways to get vitamin D are by skin exposure to sunlight, which can carry potential risks, and by taking vitamin D supplements. Some foods also provide vitamin D, including egg yolks, salmon and fortified milk, orange juice and cereal.