A vegetarian diet that is not well-balanced can lead to nutritional
deficiencies:
Inadequate protein intake: This is one possible, though unlikely
health risk associated with a vegetarian diet. Proteins consist of
various groupings of amino acids, to form "complete" or "incomplete"
proteins. While animal products contain complete proteins, it is
relatively easy to obtain a sufficient daily protein intake from plant
sources alone. Most plant sources (aside from soy beans) contain
incomplete proteins, which can be combined with other foods to form
complete proteins.
For example:
Pulses/legumes (see examples below) + seeds or nuts = complete
protein
Pulses/legumes + grains = complete protein
Grains + dairy = complete protein
Pulses/legumes + dairy = complete protein
Many familiar dishes contain such combinations: for example, rice and
beans, pasta and cheese, and cereal with milk.
Inadequate Vitamin B12 intake: Vitamin B12, which is produced by
bacteria in animals, is necessary to ensure the healthy functioning of
red blood cells, brain and nerve tissue. A deficiency of Vitamin B12
can cause serious health problems, especially for vegans. Nutritionists
recommend Vitamin B12 injections for long-time vegans.
Inadequate iron intake: Iron is essential for red blood cells to
transport oxygen through the bloodstream. A low intake can lead to
iron-deficiency anemia. However, many plant products do contain iron:
e.g., dark green vegetables such as spinach, kale, arugula, dandelion
greens, collard greens and broccoli, kidney beans, dried fruit, pumpkin
seeds, and iron-fortified breads and cereals. Vitamin C aids in the
absorption of iron.
Inadequate calcium intake: Calcium is necessary for the proper
development and maintenance of healthy bones and teeth.
Lactovegetarians do not generally suffer from calcium deficiency, as
dairy products are rich in calcium. Vegans can ensure adequate intake
by eating dark, leafy greens, dried figs, sunflower seeds, and
fortified cereals and soy milk. Calcium supplements can also be taken.
Inadequate Vitamin D intake: Vitamin D is involved in calcium
absorption. A deficiency can lead to rickets and osteoporosis. The body
produces its own Vitamin D when exposed to sunlight, but there are very
few naturally-occurring sources of Vitamin D in food. Dairy milk and
soy milk are often fortified with Vitamin D. Nutritionists recommend
that those who do not receive exposure to sunlight or drink milk
consider taking supplements.
A vegan diet presents special challenges for children and pregnant
women.
Toddlers who have been weaned from breast milk are often fussy
eaters.
It can be difficult to ensure adequate caloric and nutritional intake.
Careful menu planning is essential for a healthy diet during these
years.
Pregnant women require higher intakes of most vitamins and minerals.
In the latter months of pregnancy, a greater caloric intake is also
necessary. There is no indication that vegan women or their babies
suffer from more health problems than non-vegans. But once again,
careful planning to ensure adequate nutrition is advisable.