b'CARBOHYDRATE ZINCCarbohydrates provide fuel for immune cells.Some studies amongst the general population Timing of carbohydrate ingestion, rather thanindicate that zinc may have preventative and total carbohydrate intake, appears to exerttherapeutic effects on common cold. Current immunomodulatory effects, associated withconsensus statements highlight that acute prolonged, strenuous exercise. Consumptionsupplementation during intensive training periods during exercise to maintain blood glucose levelsmight be beneficial, particularly for athletes who and blunt the release of stress hormones andare prone to URTIs.cytokines, helps to attenuate exercise-induced immunodepression. MICROBE-ACCESSIBLE NUTRIENTSOMEGA-3 FATTY ACIDS Microbe-accessible nutrients like prebiotics, Long-chain omega-3 fatty acids eicosapentaenoicdietary fibre and polyphenols are metabolised by acid (EPA) and docosapentaenoic acid (DHA)the gut microbiota, fuel the growth of beneficial have been shown to have anti-inflammatory andmicroorganisms, and promote diversity, resilience, immunomodulatory activity. While the evidence isand stability of the microbiota. As such, these limited by the heterogeneity of studies, it appearsnutrients may indirectly influence the microbiota-that consuming 2g per day of combined EPA andimmune axis and support the hosts ability to DHA might have beneficial effects on inflammation,dampen an immune response and control infection muscle soreness and immune function amongstat a non-damaging level. More specifically, athletes. polyphenols and their gut-derived metabolites are widely researched for their anti-inflammatory, antioxidant and immune-regulatory properties. Research shows that high-dose supplementation of certain polyphenols may be linked to reduced URTI in athletes. However, more research is needed to VITAMIN C establish optimal dosing and the benefits of long-term consumption of polyphenols and gut-derived Vitamin C is highly researched for its antioxidantmetabolites on athlete health and immune function.function and in particular, its effects on the onset, severity, and duration of URTIs. A Cochrane review presents moderate to strong evidence that vitamin C supplementation may prevent URTI. Vitamin C supplementation (250-1000 mg/day) reduced the incidence of URTI in athletes by ~50% 18 . DIETARY MICROBESDietary microbes, such as those found in fermented foods and probiotics, have been highlighted in recent consensus statements as an important dietary component to support athlete VITAMIN D immune health. These microbes directly interact Cholecalciferol-D3 plays an important role in innatewith the commensal gut microbiota (modulation and adaptive immune function, and its deficiencyof gut bacteria, competition with pathogens for is linked with increased risk of URTI. Adequate sunbinding sites and nutrients), reinforce gut barrier, exposure, consumption of vitamin D rich foods andinteract with gut-associated lymphoid tissue and supplementation of up to 4000 IU/day whenevermediate immune signalling to a variety of organs necessary (during winter months and deficiencyand systems. Current research is mixed due to period) can help maintain vitamin D levels all yearwide variation in strain, dose and duration of round. Although higher dose supplements aresupplementation. However, there is moderate available, these are not advisable due to evidenceevidence to support daily supplementation of Lactobacillus or Bifidobacterium strains of of increased mortality in individuals with very highprobiotics containing at least 10 10live bacteria.vitamin D levels (over 140 nmol/l). 5'