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The role of vitamin D in the prevention of coronavirus disease 2019 infection and mortality.
Ilie, PC, Stefanescu, S, Smith, L
Aging clinical and experimental research. 2020;32(7):1195-1198
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The World Health Organisation declared COVID-19 caused by the virus SARS-CoV-2 a global pandemic. ACE-2 is the host cell receptor responsible for mediating infection by SARS-CoV-2. The main aim of this study was to assess the association between the mean levels of vitamin D in various countries and the mortality caused by COVID-19. A secondary aim was to identify any association/s between the mean vitamin D levels in various countries and the number of cases of COVID-19. This study is a cross-sectional analysis of based on studies carried out on European countries. Results indicate a potential crude association between the mean vitamin D levels in various European countries with COVID-19 cases and COVID-19 mortality. Authors conclude that further studies about vitamin D levels in COVID-19 patients with different degrees of disease severity should be performed.
Abstract
WHO declared SARS-CoV-2 a global pandemic. The present aim was to propose an hypothesis that there is a potential association between mean levels of vitamin D in various countries with cases and mortality caused by COVID-19. The mean levels of vitamin D for 20 European countries and morbidity and mortality caused by COVID-19 were acquired. Negative correlations between mean levels of vitamin D (average 56 mmol/L, STDEV 10.61) in each country and the number of COVID-19 cases/1 M (mean 295.95, STDEV 298.7, and mortality/1 M (mean 5.96, STDEV 15.13) were observed. Vitamin D levels are severely low in the aging population especially in Spain, Italy and Switzerland. This is also the most vulnerable group of the population in relation to COVID-19. It should be advisable to perform dedicated studies about vitamin D levels in COVID-19 patients with different degrees of disease severity.
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International Society of Sports Nutrition Position Stand: nutritional considerations for single-stage ultra-marathon training and racing.
Tiller, NB, Roberts, JD, Beasley, L, Chapman, S, Pinto, JM, Smith, L, Wiffin, M, Russell, M, Sparks, SA, Duckworth, L, et al
Journal of the International Society of Sports Nutrition. 2019;16(1):50
Abstract
Background In this Position Statement, the International Society of Sports Nutrition (ISSN) provides an objective and critical review of the literature pertinent to nutritional considerations for training and racing in single-stage ultra-marathon. Recommendations for Training. i) Ultra-marathon runners should aim to meet the caloric demands of training by following an individualized and periodized strategy, comprising a varied, food-first approach; ii) Athletes should plan and implement their nutrition strategy with sufficient time to permit adaptations that enhance fat oxidative capacity; iii) The evidence overwhelmingly supports the inclusion of a moderate-to-high carbohydrate diet (i.e., ~ 60% of energy intake, 5-8 g·kg- 1·d- 1) to mitigate the negative effects of chronic, training-induced glycogen depletion; iv) Limiting carbohydrate intake before selected low-intensity sessions, and/or moderating daily carbohydrate intake, may enhance mitochondrial function and fat oxidative capacity. Nevertheless, this approach may compromise performance during high-intensity efforts; v) Protein intakes of ~ 1.6 g·kg- 1·d- 1 are necessary to maintain lean mass and support recovery from training, but amounts up to 2.5 g.kg- 1·d- 1 may be warranted during demanding training when calorie requirements are greater; Recommendations for Racing. vi) To attenuate caloric deficits, runners should aim to consume 150-400 Kcal·h- 1 (carbohydrate, 30-50 g·h- 1; protein, 5-10 g·h- 1) from a variety of calorie-dense foods. Consideration must be given to food palatability, individual tolerance, and the increased preference for savory foods in longer races; vii) Fluid volumes of 450-750 mL·h- 1 (~ 150-250 mL every 20 min) are recommended during racing. To minimize the likelihood of hyponatraemia, electrolytes (mainly sodium) may be needed in concentrations greater than that provided by most commercial products (i.e., > 575 mg·L- 1 sodium). Fluid and electrolyte requirements will be elevated when running in hot and/or humid conditions; viii) Evidence supports progressive gut-training and/or low-FODMAP diets (fermentable oligosaccharide, disaccharide, monosaccharide and polyol) to alleviate symptoms of gastrointestinal distress during racing; ix) The evidence in support of ketogenic diets and/or ketone esters to improve ultra-marathon performance is lacking, with further research warranted; x) Evidence supports the strategic use of caffeine to sustain performance in the latter stages of racing, particularly when sleep deprivation may compromise athlete safety.
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Effect of a short-term low fermentable oligiosaccharide, disaccharide, monosaccharide and polyol (FODMAP) diet on exercise-related gastrointestinal symptoms.
Wiffin, M, Smith, L, Antonio, J, Johnstone, J, Beasley, L, Roberts, J
Journal of the International Society of Sports Nutrition. 2019;16(1):1
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A diet high in fermentable oligosaccharides, disaccharides, monosaccharaides and polyols (FODMAPs) may result in altered gut motility. Research has shown that 30-50% of endurance athletes list gastrointestinal (GI) issues as a cause of underperformance, however there is little evidence on the impact of FODMAPs during endurance training. The aim of this randomised, crossover trial was to determine the effects of a short-term, low FODMAP diet on GI symptoms and perceived ability to exercise in 16 healthy volunteers. Participants were randomly assigned to either a low FODMAP diet or high FODMAP diet for seven days with a seven-day washout period. GI symptoms, perceived ability to exercise and markers of acute GI inflammation were recorded at the beginning and end of each intervention period. This study found a short-term, low FODMAP diet reduced exercise-related GI symptoms and improved perceived ability to exercise compared with a high FODMAP diet. Based on these results, the authors recommend the therapeutic benefits of a sustained low FODMAP diet in athletes be further explored.
Abstract
BACKGROUND Research has demonstrated that low fermentable oligiosaccharide, disaccharide, monosaccharide and polyol (FODMAP) diets improve gastrointestinal (GI) symptoms in irritable bowel syndrome sufferers. Exercise-related GI issues are a common cause of underperformance, with current evidence focusing on the use of FODMAP approaches with recreationally competitive or highly trained athletes. However, there is a paucity of research exploring the potential benefit of FODMAP strategies to support healthy, recreational athletes who experience GI issues during training. This study therefore aimed to assess whether a short-term LOWFODMAP diet improved exercise-related GI symptoms and the perceived ability to exercise in recreational runners. METHODS Sixteen healthy volunteers were randomly assigned in a crossover design manner to either a LOWFODMAP (16.06 ± 1.79 g·d- 1) or HIGHFODMAP (38.65 ± 6.66 g·d- 1) diet for 7 days, with a one week washout period followed by a further 7 days on the alternate diet. Participants rated their gastrointestinal symptoms on an adapted version of the Irritable Bowel Syndrome-Severity Scoring System (IBS-SSS) questionnaire before and at the end of each dietary period. Perceived ability to exercise (frequency, intensity and duration) in relation to each dietary period was also rated using a visual analogue scale. Resting blood samples were collected prior to and on completion of each diet to determine plasma intestinal fatty acid binding protein (I-FABP) as a marker of acute GI injury. RESULTS Overall IBS-SSS score significantly reduced in the LOWFODMAP condition from 81.1 ± 16.4 to 31.3 ± 9.2 (arbitrary units; P = 0.004). Perceived exercise frequency (z = 2.309, P = 0.02) and intensity (z = 2.687, P = 0.007) was significantly improved following a short-term LOWFODMAP approach compared to HIGHFODMAP. No significant differences were reported between dietary conditions for plasma I-FABP (P > 0.05). CONCLUSIONS A short-term LOWFODMAP diet under free-living conditions reduced exercise-related GI symptoms and improved the perceived ability to exercise in otherwise healthy, recreational runners. These findings may be explained by a reduction in indigestible carbohydrates available for fermentation in the gut. The therapeutic benefits of LOWFODMAP diets in recreational and trained athletes during sustained training periods warrants further investigation.