It’s been six years since my colleagues and I wrote our paper on athletic performance and vitamin D.
And it’s been four years since I wrote a book on the subject.
So I was intrigued when Dr. Joseph Maroon and colleagues at the University of Pittsburg Medical Center measured the vitamin D levels of 55 NFL players from the Pittsburg Steelers during the off-season and correlated those levels to broken bones and being cut from the team.
The serum vitamin D levels of the players ranged from 8 to 59 ng/mL, with 68.8% of the team (n = 55) having vitamin D levels less than 32 ng/ml.The majority of the athletes (84%) were black. The black athletes had significantly lower vitamin D levels than did white athletes (25.6 vs. 37.4 ng/mL). Notably, all athletes with vitamin D levels categorized as deficient (<20 ng/ml) were black, as were 91% of the athletes with insufficient (20 – 32 ng/ml) vitamin D levels.
Athletes with levels above 32 ng/ml had played significantly more NFL seasons than athletes with deficient levels (P = .005). When correcting for number of NFL seasons played, vitamin D levels were significantly lower in the athletes who experienced a bone fracture (P = .001). The 21 players who were released during the 2012-2013 preseason had significantly lower vitamin D levels when compared with the players who made the team (P = .001).
The authors concluded,
“The vitamin D profile of professional NFL football players in our sample was more favorable than that of the general population; yet, vitamin D deficiency and insufficiency levels were found to be significant in the subset of black players evaluated. We found that vitamin D levels were inversely related to bone fracture prevalence. Furthermore, low vitamin D levels were associated with a higher risk of getting released during preseason, possibly indicating poorer performance. Based on these findings, routine monitoring and optimization of vitamin D levels should be considered as part of the routine care of NFL players, with special attention to black athletes.”
Increasingly, I am finding that sunlight offers benefits above and beyond that of vitamin D. It is easy to forget that vitamin D blood levels, as were measured in this study, are a marker for both vitamin D and sun exposure. This is why the Vitamin D Council recommends safe and sensible sun exposure, along with vitamin D supplements on the days you can’t get adequate sunshine.