This review examines the hypothesis that vitamin and mineral status in athletes is inadequate for optimal sports performance. The review is based on indicators determined from blood and on studies published since 1980. Most of the studies did not find micronutrient status in athletes to be different from untrained controls. The serum ferritin concentration in females was lower than in males (27 vs. 78 μg · L−1), and the prevalence of low serum ferritin concentration was higher in female athletes than in untrained female controls (37 vs. 23%). Supplementation of water-soluble vitamins and iron was associated with an improvement in the corresponding indicators. Excluding a few studies with mildly anemic subjects, improvements in indicators of micronutrient status were not associated with enhanced athletic performance. Consequently, the levels of indicators of micronutrient status seen in athletes' blood were apparently compatible with optimal physical performance.
Melinda M. Manore
This paper presents an overview of vitamin
Hyun Chul Jung, Myong Won Seo, Sukho Lee, Sung Woo Jung, and Jong Kook Song
The prevalence of vitamin D deficiency has become an important worldwide public health issue ( Holick & Chen, 2008 ). It is well recognized that vitamin D plays a key role in bone health ( Välimäki et al., 2004 ), muscle function ( Ceglia, 2008 ), and athletic performance ( Koundourakis et
Michelle S. Rockwell, Madlyn I. Frisard, Janet W. Rankin, Jennifer S. Zabinsky, Ryan P. Mcmillan, Wen You, Kevin P. Davy, and Matthew W. Hulver
Although initially classified as a vitamin, calciferol (vitamin D) is recognized as a hormone with widespread functionality in physiology and metabolism. There are a number of direct and indirect mechanisms by which vitamin D may influence skeletal muscle function and remodeling, including enhanced
Holden S-H. MacRae and Kari M. Mefferd
We investigated whether 6 wk of antioxidant supplementation (AS) would enhance 30 km time trial (TT) cycling performance. Eleven elite male cyclists completed a randomized, double-blind, cross-over study to test the effects of twice daily AS containing essential vitamins plus quercetin (FRS), and AS minus quercetin (FRS-Q) versus a baseline TT (B). MANOVA analysis showed that time to complete the 30 km TT was improved by 3.1% on FRS compared to B (P ≤ 0.01), and by 2% over the last 5 km (P ≤ 0.05). Absolute and relative (%HRmax) heart rates and percent VO2max were not different between trials, but average and relative power (% peak power) was higher on FRS (P ≤ 0.01). Rates of carbohydrate and fat oxidation were not different between trials. Thus, FRS supplementation significantly improved high-intensity cycling TT performance through enhancement of power output. Further study is needed to determine the potential mechanism(s) of the antioxidant efficacy.
Susan J. Massad, Nathan W. Shier, David M. Koceja, and Nancy T. Ellis
Factors influencing nutritional supplement use by high school students were assessed. Comparisons were made between various groups of sports participants and non-sports participants. The Nutritional Supplement Use and Knowledge Scale was administered to 509 students. Mean supplement use score was 10.87 (SEM = 0.50, range 0-57). Mean knowledge score was 13.56 (SEM = 0.16, range 1-21). Significant relationships (p < .01) were obtained for supplement knowledge with use, and supplement use with gender. ANOVA found significant differences between supplement use by gender (p < .01), supplement use by sports category (p < .05), and knowledge scores by sports category (p < .01). Discriminant function analysis indicated knowledge, supplement use, and subscores for protein, vitamins/minerals, and carbohydrates were best discriminators of sport group membership. Greater knowledge about supplements was associated with less use; hence, education about supplements can be a deterrent to use. This study may help coaches, athletic trainers, athletic directors, teachers, physicians, and parents identify nutritional misconceptions held by adolescents.
Hanan A. Alfawaz, Soundararajan Krishnaswamy, Latifah Al-Faifi, Halima Ali Bin Atta, Mohammad Al-Shayaa, Saad A. Alghanim, and Nasser M. Al-Daghri
for protection from cardiovascular diseases ( Nunez-Cordoba & Martinez-Gonzalez, 2011 ), calcium and vitamin D supplementation for increasing bone mineral density ( Silk et al., 2015 ), and vitamin C in preventing and treating the common cold ( Hemila & Chalker, 2013 ). Despite the absence of
Kelly Pritchett, Robert C. Pritchett, Lauren Stark, Elizabeth Broad, and Melissa LaCroix
The National Health and Nutrition Examination Survey III determined that vitamin D insufficiency (<75 nmol/L) affects over 77% of the population. According to the World Health Organization and the Endocrine Society serum 25(OH) vitamin D (25(OH)D) standards, vitamin D deficiency is defined as <50
Dana M. Lis and Keith Baar
measured in a healthy athletic human body. Therefore, the current study aimed to determine the effect of different preparations of collagen supplements on collagen synthesis rates. Subjects were provided with 15 g of vitamin C–enriched collagen either as a drink containing gelatin or HC or as a gummy
Kirsty A. Fairbairn, Ingrid J.M. Ceelen, C. Murray Skeaff, Claire M. Cameron, and Tracy L. Perry
Vitamin D is a secosteroid hormone that may directly act on skeletal muscle ( Ceglia, 2008 ; Hamilton, 2010 ). Muscle function is impaired in severe vitamin D deficiency like rickets and osteomalacia ( Wharton & Bishop, 2003 ), and supplementation of between 420 and 8,570 IU/day for 3–6 months in