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Markus Herrmann, Rima Obeid, Juergen Scharhag, Wilfried Kindermann and Wolfgang Herrmann

This study aimed to compare the vitamin B12 and folate status of recreational endurance athletes and inactive controls by modern biomarkers. In 72 athletes (38 ± 7 y) and 46 inactive controls (38 ± 9 y) serum levels of vitamin B12, methylmalonic acid (MMA), holotranscobalamin II (holoTC), folate, and homocysteine (Hcy) were measured. Vitamin B12 and folate levels of both groups were comparable, but athletes had higher median (25.−75. percentile) MMA [242 (196 to 324) versus 175 (141 to 266) nmol/L] and holoTC concentrations [67 (52 to 93) versus 55 (45 to 70) pmol/L] than controls. Hcy was slightly lower in athletes [9.2 (7.2 to 12.6) versus 10.8 (8.9 to 12.9) nmol/L]. In controls, we found the following correlations: vitamin B12 and MMA (r = −0.38), vitamin B12 and holoTC (r = 0.51), MMA and holoTC (r = −0.36). In athletes, MMA did not correlate with vitamin B12 and holoTC. Our data suggests an altered vitamin B12 metabolism in recreational athletes that needs further investigation.

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Kathleen Woolf and Melinda M. Manore

The B-vitamins (thiamin, ribofavin, vitamin B-6) are necessary in the energy-producing pathways of the body, while folate and vitamin B-12 are required for the synthesis of new cells, such as the red blood cells, and for the repair of damaged cells. Active individuals with poor or marginal nutritional status for a B-vitamin may have decreased ability to perform exercise at high intensities. This review focuses on the B-vitamins and their role in energy metabolism and cell regeneration. For each vitamin, function related to physical activity, requirement, and status measures are given. Research examining dietary intakes and nutritional status in active individuals is also presented. Current research suggests that exercise may increase the requirements for ribofavin and vitamin B-6, while data for folate and vitamin B-12 are limited. Athletes who have poor diets, especially those restricting energy intakes or eliminating food groups from the diet, should consider supplementing with a multivitamin/mineral supplement.

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Sheila A. Kopp-Woodroffe, Melinda M. Manore, Christine A. Dueck, James S. Skinner and Kathleen S. Matt

Chronic energy deficit is one of the strongest factors contributing to exercise-induced menstrual dysfunction. In such cases, macro- and micronutrient intakes may also be low. This study presents the results of a diet and exercise training intervention program, designed to reverse athletic amenorrhea, on improving energy balance and nutritional status in 4 amenorrheic athletes. The 20-week program provided a daily sport nutrition supplement and 1 day of rest/week. The intervention improved self-reported energy intake (El) and balance in all participants. The program increased protein intakes for the 3 athletes with a protein deficit to within the recommended levels for active individuals. Micronutrient intakes increased, as did serum concentrations of vitamin B12, folate, zinc, iron, and ferritin. These results indicate that some amenorrheic athletes have poor nutritional status due to restricted Els and poor food selections. A sport nutrition supplement may improve energy balance and nutritional status in active amenorrheic women.

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Jennifer L. Krempien and Susan I. Barr

Energy intakes of adults with spinal cord injury (SCI) have been reported to be relatively low, with many micronutrients below recommended amounts, but little is known about the diets of athletes with SCI. The purpose of this cross-sectional, observational study was to assess energy intakes and estimate the prevalence of dietary inadequacy in a sample of elite Canadian athletes with SCI (n = 32). Three-day self-reported food diaries completed at home and training camp were analyzed for energy (kcal), macronutrients, vitamins, and minerals and compared with the dietary reference intakes (DRIs). The prevalence of nutrient inadequacy was estimated by the proportion of athletes with mean intakes below the estimated average requirement (EAR). Energy intakes were 2,156 ± 431 kcal for men and 1,991 ± 510 kcal for women. Macronutrient intakes were within the acceptable macronutrient distribution ranges. While at training camp, >25% of men had intakes below the EAR for calcium, magnesium, zinc, riboflavin, folate, vitamin B12, and vitamin D. Thiamin, riboflavin, calcium, and vitamin D intakes were higher at home than training camp. Over 25% of women had intakes below the EAR for calcium, magnesium, folate, and vitamin D, with no significant differences in mean intakes between home and training camp. Vitamin/mineral supplement use significantly increased men’s intakes of most nutrients but did not affect prevalence of inadequacy. Women’s intakes did not change significantly with vitamin/mineral supplementation. These results demonstrate that athletes with SCI are at risk for several nutrient inadequacies relative to the DRIs.

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Chad J. Krumbach, Dave R. Ellis and Judy A. Driskell

The influences of gender, ethnicity, and sport of varsity athletes on their vitamin/mineral supplementation habits were examined. Subjects included 145 females and 266 males from 22 varsity teams; 80% were Caucasian; 12% African American; and 8% Combined-Other. Over half of the subjects took supplements. Males were more likely than females to give "too expensive" as a reason for not taking supplements, and "improve athletic performance" and "build muscle" as reasons for taking supplements. The most common supplement was multivitamins plus minerals. Females were more likely to take calcium and iron, and males vitamins B 12 and A. African Americans were the most likely to take vitamin A. Males were more likely to get supplement information from nutritionists/dietitians and self, and females from family members or friends and physicians or pharmacists. Football players were more likely to get supplement information from nutritionists/dietitians, and males in other sports from coaches/trainers. There were some differences in vitamin/mineral supplement habits of the athletes by gender, ethnicity, and sport.

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John L. Ivy, Lynne Kammer, Zhenping Ding, Bei Wang, Jeffrey R. Bernard, Yi-Hung Liao and Jungyun Hwang

Context:

Not all athletic competitions lend themselves to supplementation during the actual event, underscoring the importance of preexercise supplementation to extend endurance and improve exercise performance. Energy drinks are composed of ingredients that have been found to increase endurance and improve physical performance.

Purpose:

The purpose of the study was to investigate the effects of a commercially available energy drink, ingested before exercise, on endurance performance.

Methods:

The study was a double-blind, randomized, crossover design. After a 12-hr fast, 6 male and 6 female trained cyclists (mean age 27.3 ± 1.7 yr, mass 68.9 ± 3.2 kg, and VO2 54.9 ± 2.3 ml · kg–1 · min–1) consumed 500 ml of either flavored placebo or Red Bull Energy Drink (ED; 2.0 g taurine, 1.2 g glucuronolactone, 160 mg caffeine, 54 g carbohydrate, 40 mg niacin, 10 mg pantothenic acid, 10 mg vitamin B6, and 10 μg vitamin B12) 40 min before a simulated cycling time trial. Performance was measured as time to complete a standardized amount of work equal to 1 hr of cycling at 70% Wmax.

Results:

Performance improved with ED compared with placebo (3,690 ± 64 s vs. 3,874 ± 93 s, p < .01), but there was no difference in rating of perceived exertion between treatments. β-Endorphin levels increased during exercise, with the increase for ED approaching significance over placebo (p = .10). Substrate utilization, as measured by open-circuit spirometry, did not differ between treatments.

Conclusion:

These results demonstrate that consuming a commercially available ED before exercise can improve endurance performance and that this improvement might be in part the result of increased effort without a concomitant increase in perceived exertion.

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Dana M. Lis, Daniel Kings and D. Enette Larson-Meyer

vitamin B12 ( Agnoli et al., 2017 ) are sufficiently consumed. Hence, appropriate nutrition education is encouraged for track-and-field athletes. Potential Benefits of Vegetarian Diets Plant-based diets may offer health advantages over the typical Western diet. Vegetarian and vegan diets are associated

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D. Enette Larson-Meyer, Kathleen Woolf and Louise Burke

coenzyme ( erythrocyte transketolase [thiamine], erythrocyte glutathione reductase [riboflavin]) or the concentration of a metabolic product that arises from reduced activity of a nutrient-dependent enzyme (methylmalonic acid [vitamin B12]) ( Food and Nutrition Board of the Institute of Medicine, 1998

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Rachel Lohman, Amelia Carr and Dominique Condo

milligrams; P  = .009), magnesium (in milligrams; P  = .025), phosphorous (in milligrams; P  = .014), potassium (in milligrams; P  = .006), sodium (in milligrams; P  = .006), vitamin C (in milligrams; P  = .003), niacin (in milligrams; P  = .009), and vitamin B 12 (in micrograms; P  = .028

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Fernando Naclerio, Eneko Larumbe-Zabala, Mar Larrosa, Aitor Centeno, Jonathan Esteve-Lanao and Diego Moreno-Pérez

to that found in skeletal muscle ( Cruzat et al., 2014 ). Although whey contains higher concentrations of leucine, which seems to be an important essential amino acid for starting muscle protein synthesis ( Naclerio & Larumbe-Zabala, 2016 ), beef is a source of heme iron, zinc, vitamin B12, and