March 17 (UPI) -- Researchers at the Hospital for Special Surgery, or HSS, in New York found in a new study that more than half of college football athletes participating in the NFL Combine lacked adequate levels of vitamin D.
Vitamin D is produced by the skin from sun exposure, but is also found in milk, orange juice and fortified foods. Increased use of sunscreen and sun avoidance to protect against skin cancer may account for roughly 40 percent of the U.S. population having vitamin D deficiency, the researchers note.
"Vitamin D has been shown to play a role in muscle function and strength," Dr. Scott Rodeo, co-chief of the Sports Medicine and Shoulder Service at HSS, said in a press release. "While most prior studies have focused on the aging population as the group most likely to experience the harmful effects of inadequate vitamin D, few reports have looked at the impact on muscle injury and function in the high performance athlete."
The study included 214 college athletes who participated in the 2015 NFL Scouting Combine, a week-long annual event where college football players perform physical tests in front of coaches, general managers and scouts to potentially be drafted into the NFL.
Researchers gathered baseline data on age, body mass index, injury history and if athletes missed any games due to muscle injury.
Roughly 59 percent of college football players in the study showed abnormal serum vitamin D levels, including 10 percent of athletes with severe vitamin D deficiency.
Researchers saw a significantly higher incidence of lower extremity muscle strain and core muscle injury in participants who had low vitamin D levels. There were 14 study participants who reported missing at least one game due to muscle strain and 86 percent of those participants had low levels of vitamin D.
"Our primary finding is that NFL Combine athletes at greatest risk for lower extremity muscle strain or core muscle injury had lower levels of vitamin D," Rodeo said. "This could be related to physiologic changes that occur to muscle composition in deficient states. Awareness of the potential for vitamin D inadequacy could lead to early recognition of the problem in certain athletes. This could allow for supplementation to bring levels up to normal and potentially prevent future injury."
The study was presented at the American Academy of Orthopaedic Surgeons Annual Meeting on March 16.