|Vitamins and minerals play a key role in numerous important body functions and are thus essential to maintaining a good health. A varied diet rich in fruits and vegetables, whole cereals, fish, meat and dairy products, contains in principle more than sufficient vitamins and minerals (chromium, copper, zinc) to prevent possible deficiencies. Consequently, a varied and balanced diet excludes the need for vitamin supplements, even in the event of intensive sports practice. There is no scientific evidence that the intake of additional vitamins or chromium, copper and zinc, has any positive impact on sports performances of various kinds. As a result, individuals who are physically active within the context of improving fitness and health should first of all aspire to consistently adopt a well-balanced and healthy diet.|
However, numerous sportsmen and elite athletes often follow a low-calorie diet, whether temporarily or not, with a view to reducing their body fat percentage. In most sports, body weight is indeed a very important determinant of performances. On the other hand, a typical characteristic of endurance athletes is that, after having followed a low-calorie diet, they switch over to a (too) limited carbohydrate-rich diet during periods of intensive training and competition. The possible result is an unbalanced diet as a consequence of reduced intake of 'non-carbohydrate-rich' food products (fruits, vegetables, whole cereals, dairy products, meat and fish), which are nevertheless essential to ensure sufficient intake of the various vitamins and minerals. A low-calorie and carbohydrate rich diet may thus indeed involve a risk of vitamin deficiency. Consequently, preventive supplementation of additional vitamins is recommended in order to prevent a decrease in physical performance capacity as a result of vitamin deficiencies.