Vitamin D deficiency in individuals with a spinal cord injury: a literature review.

STUDY DESIGN: Literature review of studies investigating vitamin D status in individuals with a spinal cord injury (SCI). OBJECTIVES: Prevalence of vitamin D deficiency seems to be high in the general population. Little is known regarding such a deficiency in individuals with a SCI. This review aimed to examine the literature that investigated vitamin D status in this population. SETTING: Switzerland. METHODS: A literature review was performed to investigate the prevalence of vitamin D deficiency in individuals with a SCI and to determine the factors leading to deficiency. RESULTS: Sixteen studies which met all the inclusion criteria were identified. All of these studies assessed total serum 25-hydroxy vitamin D status in individuals with an acute or chronic SCI. Overall, the prevalence of vitamin D deficiency or insufficiency seems to be high (range: 32-93%) in this population compared with that in able-bodied persons. The main factors are immobility, low physical activity and bedrest, and therefore not enough exposure to sunlight. In addition, age, skin pigmentation, lesion level, occurrence of pressure ulcers, body mass index, season and latitude appeared to be further determinants for vitamin D deficiency. In athletes, playing their sport indoors or outdoors may have an additional role in developing vitamin D deficiency. CONCLUSION: The available studies suggest that individuals with a SCI are at increased risk for vitamin D insufficiency/deficiency. Nutritional strategies and supplementation recommendations need to be developed to prevent these conditions in SCI. SPONSORSHIP: Not applicable.

Vitamin D deficiency in Swiss elite wheelchair athletes.

STUDY DESIGN: This is a retrospective analysis of total serum 25-hydroxyvitamin D (25[OH]D) in Swiss elite wheelchair athletes. OBJECTIVES: The aim was to investigate the occurrence of vitamin D deficiency in Swiss elite wheelchair athletes over the whole year and to detect differences between winter and summer months, and between indoor and outdoor athletes. SETTING: This study was conducted in Switzerland. METHODS: A total of 164 blood samples from 72 Swiss elite wheelchair athletes (mean±s.d.: age 32±13 years) were analyzed for total serum 25[OH]D. All participants were members of the national team in their discipline. The following disciplines have been included: rugby, athletics, cycling, tennis, ski alpine, curling and basketball. According to general guidelines, insufficient vitamin D status was defined between 50 and 75 nmol l-1, deficiency below 50 nmol l-1 and severe deficiency below 27.5 nmol l-1. RESULTS: In all, 73.2% of all samples showed an insufficiency/deficiency in vitamin D status. Total serum 25[OH]D was significantly higher during summer compared with winter months (69.5±21.4 nmol l-1 vs 51.5±21.9 nmol l-1; P<0.001). Indoor sports showed a higher amount of vitamin D insufficiency/deficiency (80.9%) than outdoor sports (70.1%), with a significantly higher 25[OH]D concentration in outdoor sports (P=0.042). CONCLUSION: A high percentage of vitamin D deficiency was found among Swiss elite wheelchair athletes. Conclusively, we recommend supplementation with vitamin D-especially during winter-to prevent a deficiency and an impairment of performance.

Reliability of a 3-min all-out Arm Crank Ergometer Exercise Test.

The 3-min all-out test is a well-established exercise test developed for cycling ergometry. However, no such test exists in arm cranking. Thus the aim of this study was to investigate the test-retest reliability of a 3-min all-out exercise test on an arm crank ergometer. 21 healthy participants (9 male and 12 female, age 34±11 years, body mass 69.6±11.1 kg and height 175.5±6.9 cm) twice performed a 3-min all-out exercise test on an arm crank ergometer separated by 7 days. Peak power (PP), mean power (MP), fatigue index (FI), time to peak (TTP) and total work (TW) were assessed to detect test-retest reliability. PP, MP, FI and TW showed an excellent intra-class correlation coefficient (ICC) ranging from 0.940 to 0.984. Only TTP showed very low reliability with an ICC of 0.379. The results from this test-retest analysis showed that all parameters except the TTP were highly reliable in a 3-min all-out exercise test on an arm crank ergometer in able-bodied participants.