Just as people have different reasons for not eating meat, there are different kinds of vegetarians. Some people choose this diet for reasons relating to animal rights, some are "picky" or health-conscious eaters, and some are vegetarians for religious reasons. Some of the different kinds of are lacto vegetarians, lacto-ovo vegetarians, pesca vegetarians, and vegans. None of these people eat meat or poultry; pesca vegetarians are the only type that eat fish.
Lacto vegetarians are those who eat dairy products; however, they do not eat eggs. Lacto-ovo vegetarians include dairy and eggs in their diet. Pesca vegetarians eat everything that lacto-ovo vegetarians do but they also consume fish.
Vegans differ from all the other types as they eat only plant based foods and consume no animal products of any kind. The vegan diet is the strictest vegetarian diet. Vegans must plan their diets carefully to ensure they get all of the nutrients they need each day. Vegans are typically prone to deficiencies in protein, calcium, iron, zinc, and vitamin B12.
Vegans can easily develop a protein deficiency because plant based proteins are incomplete proteins. Since the human body cannot manufacture all of the necessary amino acids to build proteins, we rely on food to supply our bodies with complete proteins. Animal protein sources are complete proteins as they contain all of the amino acids needed to build a protein strand. However, using a concept called complimentary proteins different plant foods can be combined to form complete proteins. Common complimentary protein combinations are grains plus beans or grains plus legumes. Rice and beans or a peanut butter sandwich are also complete proteins.
Dairy foods such as cheese, eggs, and yogurt are complete proteins, so for most of the other types of vegetarians obtaining protein is not too much of a problem. Vegans must consume nuts, legumes, and seeds in combination with whole grains or soy foods to form complete proteins.
Vegetarians can obtain calcium and vitamin D from milk, however, vegans can drink soy milk with calcium and vitamin D added. Tofu, broccoli, nuts, legumes, seeds, and some ready-to-eat cereals contain some calcium. Orange juice fortified with calcium is also available.
Although iron from animal sources is more easily absorbed by the body, vegetarians can obtain iron by combining a food high in vitamin C with an iron-rich food to help the body better absorb the iron. Tofu and broccoli, whole wheat bread or toast and an orange or orange juice, and spinach and tomatoes are some examples of good combinations.
Vitamin B12 is found only in animal proteins, so vegans need to eat cereals and other foods that have B12 added. Adequate amounts of zinc are found in dairy foods, so all of the different kinds of vegetarians except vegans can obtain enough zinc from these. Seeds, nuts, tofu, legumes, wheat germ and bran are common sources of zinc for vegans. However, some vegans take a multivitamin that includes zinc, as it is more difficult for the body to absorb non-animal sources of zinc. Care must be taken to never exceed 100% of the Recommended Dietary Allowance (RDA) for zinc, as too much zinc can be harmful to the body.