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Mikael Fogelholm

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.

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Melinda M. Manore

This paper presents an overview of vitamin B6 and exercise, including the role that vitamin B6 plays in gluconeogenesis and glycogenolysis and changes in vitamin B6 metabolism during exercise. The dietary vitamin B6 intakes of athletes are also reviewed. Most studies report that male athletes have adequate dietary intakes of vitamin B6, whereas some females, especially those with low energy intakes, appear to have low vitamin B6 intakes. Few studies have assessed the vitamin B6 status of nonsupplementing athletes using the recommended status criteria. The role that vitamin B6 may play in attenuating the rise in plasma growth hormone observed during exercise is also reviewed. Finally, recomrnendations are given for further research in the area of vitamin B6 and exercise.

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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

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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

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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

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Matthew A. Wyon, Roger Wolman, Nicolas Kolokythas, Karen Sheriff, Shaun Galloway and Adam Mattiussi

A worldwide vitamin D deficiency has been frequently reported in the scientific literature over the past 20 years. 1 The majority of studies have focused on the adult population but the few studies that have used adolescent populations have reported similar deficiency and insufficiency rates. 2

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Christopher Tack, Faye Shorthouse and Lindsy Kass

; Uzgare et al., 2009 ) and tensile breaking strength ( Shukla et al., 1999 ). More specifically, vitamins and vitamin-related compounds can increase growth factor release (retinoids; Wicke et al., 2000 ) as well as enhance tensile breaking strength (vitamin E-like antioxidant, Raxofelast; Galeano et

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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

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Emily M. Haymes

Vitamin and mineral supplements are frequently used by competitive and recreational athletes. Dietary deficiencies of most vitamins are not very common among athletes except in those who restrict their food intake in order to maintain body weight. Vitamins most likely to be deficient in the diet are folate, B6, B12, and E. Biochemical evidence of vitamin deficiencies in some athletes have been reported for thiamine, riboflavin, and B6. When the diet is deficient, vitamin supplements may improve performance but are not likely to be effective if the dietary intake is adequate. Some female athletes' diets are low in calcium, iron, and zinc. Low calcium intake may reduce peak bone mass in young women. Iron deficiency may impair performance and needs to be corrected with an iron supplement. Zinc supplements that exceed the RDA interfere with the absorption of copper and lower HDL-cholesterol.

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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.