Do vegetarians meet all their nutritional needs?

From the American Dietetic Association -

"It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life-cycle including pregnancy, lactation, infancy, childhood and adolescence and for athletes."