In general, coronary heart disease, high blood pressure, type 2 diabetes, obesity and some forms of cancer tend to develop less often in vegetarians than in nonvegetarians. A well-planned vegetarian diet may help prevent and treat kidney disease. Although some health advantages may reflect other healthful lifestyle practices, such as regular exercise and refraining from smoking, diet is clearly a contributing factor. Like nonvegetarian diets, vegetarian diets can be healthful if they are properly planned. The key is to be sure they provide enough calories to meet energy needs and include a wide variety of foods.
Protein is found in most plant foods as well as in animal foods.
Many plant foods contain calcium. Vegans may have lower calcium needs than nonvegetarians, since diets that are lower in protein help the body retain more calcium. Diets that are low in sodium also help the body retain calcium. Until more is known about calcium requirements for vegans, vegans should strive to meet the calcium requirements for the general public by regularly including plant sources of calcium. Vegans don't need a calcium supplement unless they do not meet their calcium requirements from food on most days.