Effect of 12-Week Vitamin D Supplementation on 25[OH]D Status and Performance in Athletes with a Spinal Cord Injury.
(1) BACKGROUND: studies with able-bodied athletes showed that performance might possibly be influenced by vitamin D status. Vitamin D seems to have a direct impact on neuromuscular function by docking on vitamin D receptors in the muscle tissue. Additionally, a high prevalence of vitamin D deficiency was shown not only in infants and in the elderly but also in healthy adults and spinal cord injured individuals. Therefore, the aim of our study was to investigate whether a vitamin D dose of 6000 IU daily over 12 weeks would be sufficient to increase vitamin D status in indoor wheelchair athletes to a normal or optimal vitamin D level and whether vitamin D deficiency is associated with an impairment in muscle performance in these individuals; (2) METHODS: vitamin D status was assessed in indoor elite wheelchair athletes in order to have a baseline measurement. If vitamin D status was below 75 nmol/L, athletes were supplemented with 6000 IU of vitamin D daily over 12 weeks. A vitamin D status over 75 nmol/L was supplemented with a placebo supplement. Vitamin D status, as well as a Wingate test and an isokinetic dynamometer test, were performed at baseline and after six and 12 weeks; (3) RESULTS: 20 indoor elite wheelchair athletes participated in this double-blind study. All of these athletes showed an insufficient vitamin D status at baseline and were, therefore, supplemented with vitamin D. All athletes increased vitamin D status significantly over 12 weeks and reached an optimal level. Wingate performance was not significantly increased. Isokinetic dynamometer strength was significantly increased but only in the non-dominant arm in isometric and concentric elbow flexion; (4) CONCLUSION: a dose of 6000 IU of vitamin D daily over a duration of 12 weeks seems to be sufficient to increase vitamin D status to an optimal level in indoor wheelchair athletes. It remains unclear, whether upper body performance or muscle strength and vitamin D status are associated with each other.
Institute of Sports Medicine, Swiss Paraplegic Centre Nottwil, Nottwil 6207, Switzerland. joelle.flueck@paraplegie.ch.
Joelle Leonie
JL
Flueck
Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich 8092, Switzerland. maxwschlaepfer@gmail.com.
Max Walter
MW
Schlaepfer
Institute of Sports Medicine, Swiss Paraplegic Centre Nottwil, Nottwil 6207, Switzerland. claudio.perret@paraplegie.ch.
Claudio
C
Perret
D000293:Adolescent; D000328:Adult; D056352:Athletes; D002118:Calcium; D002547:Cerebral Palsy; D019587:Dietary Supplements; D006233:Persons with Disabilities; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D008875:Middle Aged; D013119:Spinal Cord Injuries / Q000097:blood*; D013177:Sports; D064133:Sports Nutritional Physiological Phenomena; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood; D055815:Young Adult
D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium
25[OH]D; anaerobic performance test; dynamometer test; spinal cord injuries
Int J Sport Nutr Exerc Metab. 2015 Aug;25(4):317-25
25203157
J Sci Med Sport. 2014 Jan;17(1):8-12
23619160
Endocr Rev. 2013 Feb;34(1):33-83
23169676
J Rehabil Res Dev. 2013;50(9):1177-86
24458959
J Clin Endocrinol Metab. 2014 Nov;99(11):4336-45
25033068
Open Cardiovasc Med J. 2015 Mar 30;9:40-9
25866591
Biomed Res Int. 2015;2015:953241
26000306
Clin Endocrinol (Oxf). 2010 Oct;73(4):445-51
20455886
J Gerontol A Biol Sci Med Sci. 2012 Nov;67(11):1205-11
22503994
Med Sci Sports Exerc. 1982;14(5):377-81
7154893
Calcif Tissue Int. 2013 Feb;92(2):151-62
22968766
Clin J Sport Med. 2010 Sep;20(5):368-71
20818195
Cerebrovasc Dis. 2005;20(3):187-92
16088114
J Am Geriatr Soc. 2011 Dec;59(12):2291-300
22188076
BMC Cancer. 2015 Mar 08;15:106
25884436
J Sci Med Sport. 2014 Jan;17(1):139-43
23623203
J Spinal Cord Med. 2005;28(2):109-13
15889698
J Clin Endocrinol Metab. 2011 Jul;96(7):1911-30
21646368
Unfallchirurg. 2003 Jan;106(1):13-9
12552388
Br J Sports Med. 2013 Jul;47(11):692-6
23410885
Clin Pediatr (Phila). 2014 Dec;53(14):1345-51
25006113
Curr Sports Med Rep. 2010 Jul-Aug;9(4):220-6
20622540
J Steroid Biochem Mol Biol. 2007 Mar;103(3-5):708-11
17368188
Acta Physiol Scand. 1997 Sep;161(1):31-9
9381947
J Spinal Cord Med. 2003 Summer;26(2):141-4
12828291
J Strength Cond Res. 2016 Sep;30(9):2648-55
26808860
Mol Cell Endocrinol. 2002 Nov 29;197(1-2):1-13
12431790
Arch Public Health. 2014 Sep 28;72(1):32
25279143
Nutrients. 2016 Jun 17;8(6):
27322316
J Clin Endocrinol Metab. 2009 Feb;94(2):559-63
19033372
Clin J Sport Med. 2016 Jul;26(4):279-84
26535872
Sports Med. 2015 Mar;45(3):365-78
25277808
J Spinal Cord Med. 2005;28(3):203-7
16048137
Osteoporos Int. 1998;8(3):222-30
9797906
J Spinal Cord Med. 2011;34(5):455-60
22118252
Nutr Res. 2013 Apr;33(4):251-8
23602241
Osteoporos Int. 2011 Mar;22(3):859-71
20924748
Spinal Cord. 2016 Nov;54(11):991-995
26976532
Int J Sport Nutr Exerc Metab. 2013 Oct;23(5):441-8
23535936
J Sci Med Sport. 2015 Sep;18(5):575-80
25156880
Am J Clin Nutr. 2003 Jan;77(1):204-10
12499343
PM R. 2010 Mar;2(3):202-8; quiz 228
20359685
Biochem Biophys Res Commun. 2015 Apr 24;460(1):53-71
25998734