NFL team less likely to cut players with high levels of vitamin D – Feb 2015

---

Vitamin D Profile in National Football League Players - 2015

Am J Sports Med. 2015 Feb 3. https://doi.org/10.1177/0363546514567297
Maroon JC1, Mathyssek CM1, Bost JW2, Amos A1, Winkelman R1, Yates AP3, Duca MA3, Norwig JA4.

BACKGROUND:
By maintaining phosphate and calcium homeostasis, vitamin D is critical for bone health and possibly physical performance. Hence, vitamin D is important to athletes. Few studies have investigated vitamin D levels in relation to fractures and performance in athletes, and no published study has included a multiracial sample of professional American football players.

PURPOSE:
To assess vitamin D levels, including the prevalence of vitamin D deficiency/insufficiency, in professional American football players and to evaluate the association of vitamin D levels with race, fracture history, and the ability to obtain a contract position, which may be a marker for athletic performance.

STUDY DESIGN: Cohort study; Level of evidence, 3.

METHODS:
Serum vitamin D levels of 80 professional football players from a single team in the National Football League were obtained during the 2011 off-season (mean age, 26.5 ± 3.7 years; black, n = 67 [84%]). These levels were used to compare injury reports from the 2011-2012 and 2012-2013 seasons. Statistical analyses were performed to test if vitamin D levels were related to race, fracture history, and the ability to obtain a contract position.

RESULTS:
Mean vitamin D level was 27.4 ± 11.7 ng/mL, with significantly lower levels for

• black players (25.6 ± 11.3 ng/mL) versus
• white players (37.4 ± 8.6 ng/mL; F 1,78 = 13.00, P = .001).

All athletes who were vitamin D deficient were black. When controlling for number of professional years played, vitamin D levels were significantly lower in players with at least 1 bone fracture when compared with no fractures. Players who were released during the preseason because of either injury or poor performance had significantly lower vitamin D levels than did players who played in the regular season.

CONCLUSION:
Black professional football players have a higher rate of vitamin D deficiency than do white players. Furthermore, professional football players with higher vitamin D levels were more likely to obtain a contract position in the National Football League. Professional football players deficient in vitamin D levels may be at greater risk of bone fractures.

 Download the PDF from sci-hub via Vitamin D Life

---

The Association of Vitamin D Status in Lower Extremity Muscle Strains and Core Muscle Injuries at the National Football League Combine - 2017

Arthoscopy Dec 2017
Brian J. Rebolledo, M.D M.D. Brian J. Rebolledo M.D. Brian J. Rebolledo, Johnathan A. Bernard, M.D., Brian C. Werner, M.D., Andrea K. Finlay, Ph.D., Benedict U. Nwachukwu, M.D., M.B.A., David M. Dare, M.D., Russell F. Warren, M.D., Scott A. Rodeo, M.D.
DOI: http://dx.doi.org/10.1016/j.arthro.2017.10.005

Purpose
To evaluate the association between serum vitamin D level and the prevalence of lower extremity muscle strains and core muscle injuries in elite level athletes at the National Football League (NFL) combine.

Methods
During the 2015 NFL combine, all athletes with available serum vitamin D levels were included for study. Baseline data were collected, including age, race, body mass index, position, injury history specific to lower extremity muscle strain or core muscle injury, and Functional Movement Screen scores. Serum 25-hydroxyvitamin D was collected and defined as normal (≥32 ng/mL), insufficient (20-31 ng/mL), and deficient (<20 ng/mL). Univariate regression analysis was used to examine the association of vitamin D level and injury history. Subsequent multivariate regression analysis was used to examine this relation with adjustment for collected baseline data variables.

Results
The study population included 214 athletes, including 78% African American athletes and 51% skilled position players.

• Inadequate vitamin D was present in 59%, including 10% with deficient levels.
• Lower extremity muscle strain or core muscle injury was present in 50% of athletes, which was associated with lower vitamin D levels (P = .03).
• Athletes with a positive injury history also showed significantly lower vitamin D levels as compared with uninjured athletes (P = .03).
• African American/black race (P < .001) and injury history (P < .001) was associated with lower vitamin D.
• Vitamin D groups showed no differences in age (P = .9), body mass index (P = .9), or Functional Movement Screen testing (P = .2).
• Univariate analysis of inadequate vitamin D levels showed a
  • 1.86 higher odds of lower extremity strain or core muscle injury (P = .03), and
  • 3.61 higher odds of hamstring injury (P < .001).

Multivariate analysis did not reach an independent association of low vitamin D with injury history (P = .07).

Conclusions
Inadequate vitamin D levels are a widespread finding in athletes at the NFL combine. Players with a history of lower extremity muscle strain and core muscle injury had a higher prevalence of inadequate vitamin D.

Level of Evidence: Level IV, retrospective study-case series.

---

See also Vitamin D Life

• NCAA trainers are getting on board the Vitamin D train (40-50 ng)– Nov 2019
• Athletes (national-level) with less than 10 ng of vitamin D had smaller hearts – Jan 2014
• 5,000 IU vitamin D helped UK professional athletes in the winter – Oct 2012
• Many athletes now advised to take daily vitamin D supplements – Aug 2014
• NHL discovers Vitamin D – their ideal is 40-120 ng – 2016
• Overview Fractures and vitamin D

Sports benefits from up to 50 ng(click on chart for details)

Overview Sports and vitamin D has the following summary
Athletes are helped by vitamin D by:

1. Faster reaction time
2. Far fewer colds/flus during the winter
3. Less sore/tired after a workout
4. Fewer micro-cracks and broken bones
5. Bones which do break heal much more quickly
6. Increased VO2 and exercise endurance Feb 2011
7. Indoor athletes especially need vitamin D
8. Professional indoor athletes are starting to take vitamin D and/or use UV beds
9. Olympic athletes have used UV/vitamin D since the 1930's
10. The biggest gain from the use of vitamin D is by those who exercise less than 2 hours per day.
11. Reduced muscle fatigue with 10,000 IU vitamin D daily
12. Muscle strength improved when vitamin D added: 3 Meta-analysis
13. Reduced Concussions
    See also: Sports and Vitamin D category 231 items