Abstract

Well-planned vegetarian diets can meet nutritional requirements and provide health benefits. However, critical nutrients such as iron, calcium, zinc, omega-3 fatty acids, and vitamin B12 require special attention due to their lower bioavailability or absence of exclusively plant-based foods. This study aimed to review national and international consensus statements and guidelines directed at the adult vegetarian population, identifying recommendations regarding the intake and supplementation of these nutrients. An integrative literature review was conducted using the databases LILACS, COCHRANE, PUBMED, SCOPUS, Web of Science, CINHAL, and EMBASE, including guidelines and consensus documents for vegetarian adults. The Brazilian Vegetarian Society guide (2012) was considered for comparative purposes. Five international and one national document were selected. A consensus was observed regarding the need for iron intake 80% higher than the DRIs, with emphasis on dietary factors that modulate absorption. For zinc, no specific numeric values were established, but attention to bioavailability is recommended, particularly in diets rich in phytates. Calcium recommendations are similar to those for the general population, with emphasis on the intake of low-oxalate vegetables and fortified foods. For omega-3 fatty acids, regular intake of alpha-linolenic acid sources is recommended, with possible supplementation of microalgae-derived DHA in specific situations. Vitamin B12 supplementation is unanimously recommended across all guidelines, being mandatory for vegans and also indicated for lacto-ovo-vegetarians. In conclusion, the analysedguidelines converge on practical recommendations that may support professional practice with adult vegetarians. Individualized counselling, grounded in updated evidence, is essential for health promotion and the prevention of nutritional deficiencies, while the strengthening of national guidelines may contribute to more consistent clinical practices in the care of this population.