title: Prevalence of Vitamin D Insufficiency in Professional Hockey Players.
abstract: BACKGROUND
  Vitamin D is a fat-soluble hormone that plays a role in bone health, muscle function, and athletic performance. Studies have shown that low levels of vitamin D can lead to slower muscle recovery and function, increased rates of stress fractures, and even poorer athletic performance. Insufficient vitamin D levels have been demonstrated in professional basketball and football players, however, there have been no studies to date reviewing vitamin D insufficiency in professional hockey players.
  
  
  OBJECTIVE
  The purpose of this study was to perform a cross-sectional review to determine the prevalence of vitamin D deficiency and insufficiency in professional hockey players. The hypothesis was that there would be a high percentage of players with vitamin D insufficiency.
  
  
  METHODS
  Cross-sectional study; Level of evidence, 3.
  
  
  METHODS
  The preseason serum 25-hydroxy (OH) vitamin D laboratory test results of 105 professional hockey players were retrospectively reviewed. All players on 3 National Hockey League (NHL) teams were included. Player parameters evaluated included age, height, weight, body mass index, and 25(OH) vitamin D level. Players were divided into 4 groups based on serum vitamin D levels: deficient (<20 ng/mL), insufficient (20-31.9 ng/mL), sufficient (≥32 ng/mL), and ideal (≥40 ng/mL). Descriptive statistics were performed, in addition to 2-group and 3-group comparisons.
  
  
  RESULTS
  The average 25(OH) vitamin D level of 105 players was 45.8 ± 13.7 ng/mL (range, 24-108 ng/mL). No players in the study were considered deficient. A total of 14 players (13.3%) were considered insufficient, while 91 players (86.7%) were considered sufficient. However, only 68 players (64.8%) were considered ideal. When comparing groups, athletes with sufficient vitamin D levels were older than athletes with insufficient vitamin D levels (25.9 vs 23.1 years;P= .018). All other player parameters demonstrated no significant difference between groups.
  
  
  CONCLUSIONS
  Despite playing a winter sport and spending a great deal of time training indoors, professional hockey players have low levels of vitamin D insufficiency.
authors.affiliation: Kerlan-Jobe Orthopaedic Clinic, Los Angeles, California, USA.
authors.forename: Nima
authors.initials: N
authors.lastname: Mehran
authors.affiliation: Kerlan-Jobe Orthopaedic Clinic, Los Angeles, California, USA.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Schulz
authors.affiliation: Sports Medicine Long Island, New Hyde Park, New York, USA.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Neri
authors.affiliation: UT Southwestern Medical Center, Dallas, Texas, USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Robertson
authors.affiliation: Kerlan-Jobe Orthopaedic Clinic, Los Angeles, California, USA.
authors.forename: Orr
authors.initials: O
authors.lastname: Limpisvasti
keywords: NHL; National Hockey League; insufficiency; professional; vitamin D