Journal Title (Medline/Pubmed accepted abbreviation): Int. J. Sport Nutr. Exerc. Metab.
Page numbers: 507-514
doi (if applicable):
Summary of Background and Research Design
Background: Ultraendurance athletes, as those training for an Ironman or an Olympic-distance triathlon, can undertake 14.5-21 hrs of training per week, or more. Matching energy intake as well as vitamin and mineral intake is important for best performance and for optimum health. The benefits of vitamin and mineral supplementation are controversial, with some evidence that there can be negative side effects of excess vitamin supplementation.
Hypothesis/Research Question:What is the current frequency of vitamin and mineral supplementation in ultraendurance triathletes? What are their motivations?
Subjects:24 male and 13 female ultraendurance athletes, recruited from an Australian Ironman internet forum
Experimental design:Participants completed 7-day food diaries including vitamin and mineral supplementation
Summary of research findings:
All athletes consumed less vitamin D than the recommended daily intake (RDI) but participants consumed adequate amounts of all other nutrients. Vitamin D can be synthesized in the body if the athletes are exposed to enough sunlight. Their actual vitamin D status was not investigated however, but could be within a healthy range depending on sun exposure. Men and women both consumed more for than the RDI for folate, iron, thiamin, and vitamin B6, though women consumed more fiber and men consumed more folate, thiamin, and vitamin B6. Dietary supplements were consumed by 23 out of the 37 subjects (62% total; 69% of females and 58% of males). Vitamin C and vitamin E supplements were most popular and the most common reason was to reduce the frequency and severity of colds, increase the immune system, or follow advice from their coach. This was interesting, considering that approximately 90% of the subjects met the RDI for both vitamins C and E via diet alone and that, on a mean basis, intakes of these vitamins were >100% RDI.
Interpretation of findings/Key practice applications:
Consuming additional vitamin and/or mineral supplements is probably not necessary for ultraendurance athletes who are meeting their energy requirements with a balanced diet.