Vitamin D3 supplementation using an oral spray solution resolves deficiency but has no effect on VO2 max in Gaelic footballers: results from a randomised, double-blind, placebo-controlled trial.
Eur J Nutr
; 56(4): 1577-1587, 2017 Jun.
Article
in En
| MEDLINE
| ID: mdl-27015912
ABSTRACT
PURPOSE:
Vitamin D inadequacy is a global health concern in athletes as well as the general population. Whilst the role of vitamin D in skeletal health is well defined, there remains uncertainty over whether vitamin D supplementation has an added benefit beyond bone health.METHODS:
This randomised placebo-controlled trial in healthy male and female Gaelic footballers (n = 42) investigated the effect of vitamin D3 supplementation [3000 IU (75 µg) daily for 12 weeks, via an oral spray solution] on VO2 max which was the primary outcome measure. Secondary outcomes included skeletal muscle and lung function.RESULTS:
Supplementation significantly increased total 25-hydroxyvitamin D concentrations compared to the placebo group (mean ± SD change from baseline, 36.31 ± 32.34 vs. 6.11 ± 23.93 nmol/L, respectively; P = 0.006). At baseline, 50 and 22 % of footballers presented with vitamin D insufficiency (31-49 nmol/L) and deficiency (<30 nmol/L), respectively. Total 25-hydroxyvitamin D concentration did not significantly correlate with any measure of physical performance. Analysis of covariance (ANCOVA) models demonstrated that vitamin D supplementation over 12 weeks had no significant effect on VO2 max (P = 0.375), vertical jump height (P = 0.797), left and right handgrip strength (P = 0.146 and P = 0.266, respectively), forced vital capacity (P = 0.573) or forced expiratory volume at 1 s (P = 0.665), after adjusting for confounders. The high prevalence of vitamin D inadequacy observed in this cohort of collegiate Gaelic footballers supports the need for vitamin D supplementation during wintertime to avoid being at risk of poor bone health.CONCLUSIONS:
Twelve-week daily supplementation with 3000 IU (75 µg) vitamin D3 successfully resolved deficiency but did not have any significant effect on VO2 max, skeletal muscle or lung function.Key words
Full text:
1
Database:
MEDLINE
Main subject:
Oxygen Consumption
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Vitamin D Deficiency
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Cholecalciferol
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Dietary Supplements
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Sports Nutritional Physiological Phenomena
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Football
Type of study:
Clinical_trials
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Prognostic_studies
/
Risk_factors_studies
Limits:
Adolescent
/
Adult
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Female
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Humans
/
Male
Language:
En
Year:
2017
Type:
Article