Wikipedia.com - Poorly planned vegetarian diets may be low in vitamin B12, calcium, omega-3 fatty acids, vitamin D, iron, zinc, riboflavin (vitamin B2), and iodine, and poorly planned vegan diets may have particularly low intakes of vitamin B12 and calcium. Nonetheless, well-balanced vegetarian and vegan diets can meet all these nutrient requirements and are appropriate for all stages of the life cycle, including during pregnancy, lactation, infancy, childhood, and adolescence.Many tools are available to help vegetarians maintain an adequate nutrient balance including several Vegetarian Diet Pyramids.
Protein
The typical vegetarian gets adequate protein as long as caloric intake is adequate and a variety of foods is eaten.Vegetarian diets tend to be lower in protein than non-vegetarian diets but typically meet or exceed daily protein intake recommendations,which is believed to be beneficial.Plant sources of protein include soy beans (and soy products such as tofu, veggie burgers, soy milk, etc.), other legumes, nuts and seeds, and grains.
Protein
The typical vegetarian gets adequate protein as long as caloric intake is adequate and a variety of foods is eaten.Vegetarian diets tend to be lower in protein than non-vegetarian diets but typically meet or exceed daily protein intake recommendations,which is believed to be beneficial.Plant sources of protein include soy beans (and soy products such as tofu, veggie burgers, soy milk, etc.), other legumes, nuts and seeds, and grains.
Combining proteins
Despite a widespread belief that vegetarians must eat grains and beans within a few hours of each other in order to make a 'complete' protein which contains all 9 "essential amino acids", this has never been substantiated by research. The protein-combining theory was brought to popular attention in Frances Moore Lappé's 1971 bestseller Diet for a Small Planet.In later editions of the book, as early as 1981, Lappé withdrew her contention that protein 'combining' is necessary.
Iron
In several studies, vegans and other vegetarians were not found to suffer from iron-deficiency more than non-vegetarians. However, while one study agreed that iron-deficiency anemia
is not more common among vegetarians, they found "vegetarian children
had ... reduced levels of haemoglobin and iron compared to omnivores"
due "to the absence of animal iron sources with high utilizability".
Another study, in India, found that "strict vegetarian mothers as well
as their newborns have a greater incidence and risk of anemia and iron
deficiency."
Tofu can be a valuable source of protein, iron, zinc and calcium
The recommended iron intake for vegetarians is 1.8 times that of nonvegetarians, due to the fact that plants, dairy, and eggs contain only non-heme iron, and this is absorbed less efficiently than heme iron. Although a lower percentage of non-heme iron is absorbed, greater amounts
of non-heme iron are concentrated in many non-meat sources of iron
(than the amount of iron per serving in meats), and therefore, cereals,
eggs, nuts, seeds, and legumes (including soy foods, peas, beans,
chickpeas, and lentils) are significant sources of iron,
and a well-planned vegetarian diet should not lead to iron deficiency,
but fruitarianism and raw foods diets should not be pursued for infants
or children. Meat, fish, and poultry (not dairy or eggs) are the only sources of heme iron; intake of heme iron may be associated with colon cancer.Non-heme iron is more sensitive to both inhibitors and enhancers of iron absorption. Vitamin C is an iron absorption enhancer. The main inhibitors for most people are phytates (e.g. legumes and grains), but other inhibitors include tannins (tea, wine), calcium and polyphenols.
Iron is an integral part of many proteins and enzymes which maintain good health. In humans, iron is an essential component of proteins involved in red blood cells' oxygen transport. Iron also helps regulate cell growth and differentiation.
Major plant sources of zinc include cooked dried beans, sea vegetables, fortified cereals, soyfoods, nuts, peas, and seeds.
Eggs are an excellent source of vitamin B12 for vegetarians.
Vitamin B12 deficiency is potentially extremely serious, leading to megaloblastic anemia, nerve degeneration and irreversible neurological damage.
Lacto-ovo vegetarians may get vitamin B12 from eggs and dairy products (milk, cheese, etc) for some this is adequate but some may still remain B12-deficient. The world's largest group of professional dietitians says the form of vitamin B12 sourced from animal-products is protein-bound and not as easily digested, especially as people age, and therefore recommends B12 supplementation for everyone over the age of 50. Pregnant and lactating vegetarians (and breastfed infants if the mother's diet is not supplemented) should also use supplements, whether pills, injections, or B12-fortified foods, if they don't get adequate B12 from animal-products like eggs or dairy.
Generally, humans need only 2.4-3 micrograms of B12 each day. Although some argue that developing a disease from B12 deficiency by following a sensible diet is extremely rareless than one chance in a million, there are cases to suggest that vegetarians and vegans who are not taking vitamin B12 supplements or food fortified with B12, do not consume sufficient servings of B12 and have abnormally low blood concentrations of vitamin B12. This is because, unless fortified, plant foods do not contain reliable amounts of active vitamin B12.
It is essential, therefore, that vegetarians consume adequate amounts of dietary supplements or foods that have been fortified with B12 (such as nutritional yeast or other yeast extracts, vegetable stock, veggie burger mixes, textured vegetable protein, soy milks, vegetable and sunflower margarines, and breakfast cereals). B12 that is to be used in these supplements is typically grown from vegan sources (such as bacteria). Another bacterial source happens to be that plants and edible fungi (like mushrooms) on farms or in the wild may absorb vitamin B12 from bacteria in soil, but since modern pesticides kill most B12 in the soil (including on organic farms to some degree, as the pesticides spread, via hydrology, from non-organic farms to organic ones), the B12 in these plants is not considered a reliable dietary source, whereas B12 supplements from bacteria grown under controlled conditions are considered reliable amounts of B12. There is a patent for a cultivating vitamin B12 from plants.
Flax seed is a rich source of ALA, but contains negligible amounts of DHA and EPA, the omega-3 fatty acids the FDA considers to be healthful.
Vegetarian diets can be low in omega-3 fatty acids (O3FA). Major vegetarian sources of O3FA include algae, hempseeds and hempseed oil, walnuts, flaxseeds and flaxseed oil, olive oil, canola (rapeseed) oil, avocado and chia seeds.
However, diets lacking fish, eggs, or generous amounts of sea
vegetables (seaweed) generally lack a direct source of long-chain O3FA
such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Vegetarian diets may also have a high ratio of O6FA to O3FA, which inhibits the conversion of short-chain fatty acids such as alpha-Linolenic acid (ALA), found in most vegetarian O3FA sources, to EPA and DHA.
Short-term supplemental ALA has been shown to increase EPA levels but
not DHA levels, suggesting poor conversion of the intermediary EPA to
DHA. DHA supplements derived from DHA-rich microalgae are available, and the human body can also convert DHA to EPA.
Walnuts are a source of omega-3 fatty acids
While there is no scientific consensus on the role of omega-3 fatty acids, they may reduce the risk of coronary heart disease, lower triglycerides, stabilize mood and help prevent depression, help reduce symptoms of ADD, reduce joint pain and other rheumatoid problems, and reduce the risk of dementia in older age.[citation needed]
While there is little evidence of adverse health or cognitive effects
due to DHA deficiency in adult vegetarians or vegans, fetal and breast
milk levels remain a concern.
EPA and DHA supplementation has been shown to reduce platelet
aggregation in vegetarians, but a direct link to cardiovascular
morbidity and mortality, which is already lower for vegetarians, has yet
to be determined.
Iron is an integral part of many proteins and enzymes which maintain good health. In humans, iron is an essential component of proteins involved in red blood cells' oxygen transport. Iron also helps regulate cell growth and differentiation.
Zinc
Further information: Zinc deficiency
Western vegetarians and vegans have not been found to suffer from overt zinc deficiencies any more than meat-eaters. However, phytates
in many whole-grains and fiber in many foods may interfere with zinc
absorption and marginal zinc intake has poorly understood effects.
Vegetarians may need more than the US RDA (15 mg) of zinc daily if their
diet is high in phytates.Major plant sources of zinc include cooked dried beans, sea vegetables, fortified cereals, soyfoods, nuts, peas, and seeds.
Vitamin B12
Further information: Vitamin B12 deficiency
Lacto-ovo vegetarians may get vitamin B12 from eggs and dairy products (milk, cheese, etc) for some this is adequate but some may still remain B12-deficient. The world's largest group of professional dietitians says the form of vitamin B12 sourced from animal-products is protein-bound and not as easily digested, especially as people age, and therefore recommends B12 supplementation for everyone over the age of 50. Pregnant and lactating vegetarians (and breastfed infants if the mother's diet is not supplemented) should also use supplements, whether pills, injections, or B12-fortified foods, if they don't get adequate B12 from animal-products like eggs or dairy.
Generally, humans need only 2.4-3 micrograms of B12 each day. Although some argue that developing a disease from B12 deficiency by following a sensible diet is extremely rareless than one chance in a million, there are cases to suggest that vegetarians and vegans who are not taking vitamin B12 supplements or food fortified with B12, do not consume sufficient servings of B12 and have abnormally low blood concentrations of vitamin B12. This is because, unless fortified, plant foods do not contain reliable amounts of active vitamin B12.
It is essential, therefore, that vegetarians consume adequate amounts of dietary supplements or foods that have been fortified with B12 (such as nutritional yeast or other yeast extracts, vegetable stock, veggie burger mixes, textured vegetable protein, soy milks, vegetable and sunflower margarines, and breakfast cereals). B12 that is to be used in these supplements is typically grown from vegan sources (such as bacteria). Another bacterial source happens to be that plants and edible fungi (like mushrooms) on farms or in the wild may absorb vitamin B12 from bacteria in soil, but since modern pesticides kill most B12 in the soil (including on organic farms to some degree, as the pesticides spread, via hydrology, from non-organic farms to organic ones), the B12 in these plants is not considered a reliable dietary source, whereas B12 supplements from bacteria grown under controlled conditions are considered reliable amounts of B12. There is a patent for a cultivating vitamin B12 from plants.
Omega-3 fatty acids
