By: Marc Sorenson, EdD. Sunlight Institute–
Research published in the journal of Science and Medicine in Sport, found that professional ballet dancers were much more likely to injure themselves during winter.[i] The objective of the study was to ascertain whether lack of sunlight exposure among the dancers during winter might correlate to lowered vitamin D levels and thereby increase injury.
Elite, classical ballet dancers, 19 in all, were chosen for the investigation and were monitored during a six-month period for vitamin D levels, serum markers for bone turnover, and frequency of injuries.
It was found that vitamin D levels averaged 14.9 ng/ml in winter and 23.9 ng/ml in summer. Soft tissue injuries were nearly twice as frequent in winter (24) as in summer (13).
It is significant that soft-tissue injuries correlated so closely to low vitamin D, since vitamin D is generally thought of as a bone-strengthening hormone. Also interesting is the fact that in both summer and winter, vitamin D levels were too low. In winter, the athletes were approaching critically low levels. Vitamin D, of course, is produced by the skin in response to sunlight exposure and would be expected to be higher in summer. Still, it was not nearly high enough, and though it is conjecture, I expect that levels around 60 ng/ml would have correlated to an even lower risk of athletic injuries among the dancers.
Perhaps it is time for dancers to leave the darkness and practice routines outdoors during summer. This would help optimize vitamin D and muscle strength. Then, in the winter, sunlamps could be used for vitamin D production, or at least regular vitamin D supplementation would provide some protection against winter injuries.
[i] Wolman R, Wyon MA, Koutedakis Y, Nevill AM, Eastell R, Allen N. Vitamin D status in professional ballet dancers: Winter vs. summer. J Sci Med Sport 2013;16(5):388-391.