Nutritional and plasmatic antioxidant vitamins status of ultra endurance athletes

The "Marathon des Sables" (MDS) is a competition known to induce oxidative stress. Antioxidant vitamins prevent exercise-induced oxidative damages. The purpose of this study was to evaluate daily intake and plasma level of the main antioxidant vitamins (alpha-tocopherol, vitamin C, beta-carotene and retinol) in 19 male athletes who participated in this competition.

Data collected before the beginning of the competition included daily dietary intake using a 7-day food record and plasma biochemical measurements (alpha-tocopherol, vitamin C, beta-carotene and retinol).

First, total energy intake was obviously lower than the energetic intake usually observed in well-trained endurance athletes. Second, antioxidant vitamins intake was also insufficient. Indeed, the intake was lower than the French Dietary Reference Intakes (DRI) for this population in 18 subjects for vitamin E and 6 subjects for vitamin C, beta-carotene and Retinol Equivalent. As a significant relationship was found between total energy intake and the intake of vitamin E (r = 0.73; p < 0.001) and vitamin C (r = 0.78; p < 0.001), the low total energy intake contributed partially to the insufficient antioxidant vitamins intake. The dietary questionnaire analysis also revealed a low intake of vegetable oils, fruits and vegetables. However, plasma concentrations of these antioxidant vitamins were similar to the literature data observed in athletes.

This study evidenced obvious insufficient energy intake in ultra endurance athletes associated with a low antioxidant vitamin intake.