Adequacy of vitamin supply under maximal sustained workloads: the Tour de France.

In the Tour de France competing cyclists must pedal about 4000 km over a period of three weeks with only one day allowed for rest. The course includes 30 mountains, the highest of which reaches an altitude of approximately 2700 m. The energy expenditure values of these cyclists range from a mean of 25.4 MJ/day to peak values of 32.7 MJ/day. These are the highest values that have ever been reported for a period longer than seven days. On the basis of the food records of 5 cyclists, it turned out that 62 En.% is derived from CHO, 15 En.% from protein, and 23 En.% from fat. Since the food choice is primarily focused on digestibility and energy content, this results in a frequent consumption of sweet cakes and CHO-rich fluids. Some 49% of the energy is consumed in between meals. Such a nutritional pattern leads to a lowering of the nutrient density especially with respect to the B-vitamins. Intake of vitamins B1, B2, B6, and C, including contribution from enriched sport drinks, was 1.97 mg, 4.96 mg, 2.40 mg, and 158 mg, respectively. Besides this, intramuscular injections of megadosis vitamins of B1, B2, B6, nicotinamide, pantothenic acid, and especially B12 did increase the intake drastically. This was reflected in high blood concentrations of vitamins. Except for folic acid, vitamins (B1, B2, B6, and B12) exceeded the upper limits of the values from a reference group, particularly B12, which exceeded the reference values by up to 400%. During the Tour, vitamin concentrations remained essentially unchanged.