The effects of vitamin D3 supplementation on serum total 25[OH]D concentration and physical performance: a randomised dose–response study
Br J Sports Med doi:10.1136/bjsports-2012-091735
Graeme L Close1, Jill Leckey1, Marcelle Patterson1, Warren Bradley1, Daniel J Owens1, William D Fraser2, James P Morton1
1 Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
2 Faculty of Medicine and Health Sciences, Norwich Medical School, University of East Anglia, Norwich, UK
Correspondence to Dr Graeme L Close, Research Institute for Sport and Exercise Sciences, Tom Reilly Building, Byrom St Campus, Liverpool John Moores University, Liverpool L3 3AF, UK; g.l.close@ljmu.ac.uk
Received 4 September 2012; Revised 10 January 2013’ Accepted 17 January 2013; Published Online First 14 February 2013
Background Vitamin D deficiency is common in the general public and athletic populations and may impair skeletal muscle function. We therefore assessed the effects of vitamin D3 supplementation on serum 25[OH]D concentrations and physical performance.
Methods 30 club-level athletes were block randomised (using baseline 25[OH]D concentrations) into one of three groups receiving either a placebo (PLB), 20 000 or 40 000 IU/week oral vitamin D3 for 12 weeks. Serum 25[OH]D and muscle function (1-RM bench press and leg press and vertical jump height) were measured presupplementation, 6 and 12 weeks postsupplementation. Vitamin D deficiency was defined in accordance with the US Institute of Medicine guideline (<50 nmol/l).
Results 57% of the subject population were vitamin D deficient at baseline (mean±SD value 51±24 nmol/l). Following 6 and 12 weeks supplementation with 20 000 IU (79±14 and 85±10 nmol/l, respectively) or 40 000 IU vitamin D3 (98±14 and 91±24 nmol/l, respectively), serum vitamin D concentrations increased in all participants, with every individual achieving concentrations greater than 50 nmol/l. In contrast, vitamin D concentration in the PLB group decreased at 6 and 12 weeks (37±18 and 41±22 nmol/l, respectively). Increasing serum 25[OH]D had no significant effect on any physical performance parameter (p>0.05).
Conclusions Both 20 000 and 40 000 IU vitamin D3 supplementation over a 6-week period elevates serum 25OHD concentrations above 50 nmol/l, but neither dose given for 12 weeks improved our chosen measures of physical performance.
Summary and comment by VitaminDWiki
| Initial | 12 weeks | |
| Placebo | 20 ng | 16 ng |
| 2900 IU | 20 ng | 34 ng |
| 5700 IU | 20 ng | 36 ng |
The athletes needed one of more of the following
- more vitamin D - to get to > 40 ng
- to test for measures other than strength
endurance, muscle reaction time, reduced injuries, faster injury recovery time, etc. have all been found to be improved by vitamin D
See also VitaminDWiki
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- Muscle strength not increased by raising vitamin D to only 30 ng – RCT Aug 2012
- 8500 IU average daily helped sports performance – Oct 2010
- Professional sports team takes 5000 IU vitamin D and wins championship Hockey
- Overview Sports and vitamin D