¿Son las dietas vegetarianas nutricionalmente adecuadas? Una revisión de la evidencia científica

Vegetarian diets are booming and, although these diets have been linked to some health benefits, the low bioavailability of some micronutrients in plant foods may result in risk of nutritional deficiencies, which makes necessary adequate planning of these diets. In this regard, vitamin B12 deficiency in vegetarians has been evidenced and there is a consensus on the need of supplementation of this vitamin. Vitamin D deficiency may be more frequent than in omnivores, particularly during the winter, when skin synthesis is minimal. The low bioavailability of iron, zinc and selenium in vegetables can also affect nutritional status of vegetarians. Furthermore, vegetarian diets are usually deficient in polyunsaturated fatty acids of the omega-3 family, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. On the other hand, these diets appear to provide adequate quantities of other vitamins, such as ascorbic acid, folic acid and the fat-soluble vitamins A and E. In this review, the characteristics of the intake of macro- and micronutrients of vegetarian diets and the diet and health relationships are presented. In addition, data on nutritional status of this population are also shown and suggestions on nutritional recommendations to prevent deficiencies are given. Finally, the possible clinical application of controlled interventions with vegetarian diets is presented.