Vegan Nutrition

Vegan food pyramid

Micronutrient charts

Vitamins and Minerals in a Vegan Diet

A varied vegan diet generally provides adequate nutrition, although deficiencies in vitamins B12 and D are possible. The USDA has recently revised their opinion on vegetarian and vegan nutrition, and has acknowledged that there are plant foods that are high quality sources of protein, calcium, iron and folic acid. Following are some of the nutrients that are of particular interest to those following a vegan diet.

Protein

A common myth about the vegan diet is that you can't get enough protein. In fact, beans, seeds, nuts, grains and even vegetables such as broccoli all contain protein. Eating a variety of beans and whole grains will provide all the essential amino acids. Some plant foods provide complete protein all by themselves. Among them are soybeans, hemps seeds and quinoa.

Protein deficiency is rare. Many more health problems are caused by too much protein. Protein that is not needed for building cannot be stored by the body. It can be used as energy, but it is inferior to both carbohydrates and fats as an energy source. Breaking down and disposing of protein creates metabolic wastes, and excessive amounts can lead to toxic buildup.

Calcium

Calcium, along with vitamin D, is necessary for strong teeth and bones. It also plays a major role in proper muscle and nerve functioning.

The best vegan calcium sources are broccoli and green leafy vegetables such as kale, collard greens and bok choy. Other sources are sesame seeds, almonds, parsley, seaweed and some beans such as black beans and chickpeas. Even maple syrup contains calcium. Many other plant foods contain small amounts. To ensure an adequate supply, however, broccoli and/or green leafy vegetables should be eaten daily. Calcium can only be absorbed in the presence of magnesium, so a magnesium deficiency can lead to a calcium deficiency. Fortunately, it's easy to get enough magnesium in a vegan diet.

If you choose to take a calcium supplement, a good vegan source is dolomite, but be sure it has been certified to be free of lead, a common contaminant. Too much calcium, especially if accompanied by low levels of phosphorous and/or magnesium and vitamin D, can lead to problems such as kidney stones, calcification of the soft tissues, and possibly atherosclerosis (hardening of the arteries due to calcium plaque formation).

Magnesium

Magnesium works with calcium to keep your muscles functioning properly, including your heart muscle. Calcium aids in muscle contraction. Magnesium aids in muscle relaxation. Magnesium also helps maintain normal blood pressure and helps your body convert glucose to energy efficiently.

The best vegan source of magnesium is pumpkin seeds. Other good sources are flax seeds, almonds, peanuts, quinoa and spinach. Most seeds and nuts and many beans and whole grains contain some magnesium. Seaweed, and many vegetables and fruits have small amounts as well.

Iron

Iron is needed by the body to produce hemoglobin, and it plays a crucial role in oxygen transport in the body and in the formation of enzymes. It is possible to get too much iron, which can lead to excess production of free radicals and depressed immunity. This is less of a concern for vegans, since plant sources of iron usually contain less iron, and in a less easily absorbed form, than sources from animal products.

Natural iron can be found in lentils, beans, quinoa, spinach and other greens. Many processed foods such as breakfast cereals are fortified with iron. Cooking with cast iron cookware also provides a source of absorbable iron. Eating foods rich in vitamin C (such as cabbage or cauliflower) together with iron rich foods increases its absorption. Calcium and tannins (chemicals in coffee and tea) interfere with iron absorption when taken at the same time.

Zinc

Zinc is needed for normal growth and devleopment, and plays a role in wound healing and immunity. It has antioxidant properties and helps protect the liver. Many people in the Western world are deficient in it, which is why so many people have positive results taking zinc when they have a cold.

Zinc is found in seeds, nuts such as cashews and almonds, whole grains, and chickpeas. The body cannot store zinc so a steady dietary supply is necessary.

Folic Acid

Folic acid is a B vitamin that aids in new cell development, and for this reason adequate supplies are especially important for pregnant women. It also plays a role in the manufacture of red blood cells and a deficiency can lead to anemia.

Green leafy vegetables, rutabagas, citrus fruits and beans all provide folic acid. Many breakfast cereals, breads and other foods are fortified with it as well.

Vitamin D

Vitamin D plays a critical role in bone health, and helps regulate calcium and phosphorus absorption. Lack of vitamin D can cause bone deformation (rickets) in children, and softening of the bones in adults. There are concerns that lack of vitamin D may increase the risk of cancer and autoimmune disease.

There are no good natural vegan dietary sources of vitamin D, although many foods are fortified with vegan vitamin D. The main source for both vegans and omnivores comes from the synthesis of vitamin D triggered by skin exposure to ultraviolet light. In northern climates or if sun exposure is avoided, vegans can take supplements derived from yeast or fungi.

Not all forms of vitamin D used to fortify foods are from vegan sources. D2 is vegan. D3 is not.

Vitamin B12

Vitamin B12 is necessary for proper nerve function and maintaining healthy red blood cells. It also plays a role in cell division. A deficiency can lead to severe nervous system damage which can be irreversible. There is some evidence that low levels of B12 may play a role in allergies as well.

B12 is the most controversial nutrient with regards to the vegan diet. Many possible plant food sources have been identified, including seaweed, spirulina, miso and tempeh that has been treated in a particular way. It is unclear, however, whether these sources are in a form that is actually absorbed. Nori seaweed seems to be the plant food most likely to be a reliable source, but this has not been proven.

Vegans and vegetarians have not been found to have a higher incidence of B12 deficiency than the general population. It is thought that it can be stored in the body for up to 20 years, so it may take a long time for a deficiency to show up in former meat eaters.

Many foods are fortified with vitamin B12. A common source for vegans is a brand of nutritional yeast that is fortified with a vegan source of B12. Supplements in pill form are not easily absorbed. The preferred method of supplementation is sublingual supplements, which are drops or sprays that are placed under the tongue and absorbed directly into the blood. Transdermal B12 patches are available as well, and in extreme cases vitamin B12 shots may be needed.

Calcium aids in the assimilation of B12.

Bone Health

Bone health is determined by much more than how much calcium we consume. Magnesium, phosphorous and vitamin D all play a role in maintaining bone health. The reason there is such an emphasis on calcium is because it's the mineral that gets leached from our bones when there is too much acidity in the body.

The blood must remain within a pretty narrow pH range, yet the food we eat can cause acidic conditions very quickly. If there is not enough circulating calcium to counterbalance the acidity, the body pulls calcium, an alkaline mineral, from the bones. If this happens too much too often the bones can become brittle and weak. One of the main ways we can protect our bones is by eating a more alkalizing diet to reduce the leaching out of minerals. High protein foods and junk foods are especially acidifying. Green vegetables have an alkalizing effect. Grains are slightly acidic, except for millet which has a neutral effect.

Studies have shown that lack of regular weight-bearing exercise is strongly correlated with bone loss. Weight bearing exercise helps encourage the laying down of new bones, as long as there is an adequate supply of supporting minerals and vitamin D.

There are other factors as well. It matters how easy it is to assimilate the calcium we consume. Different forms of calcium are absorbed differently. The level of hydrochloric acid affects absorption. Oxalic acid, present in high amounts in foods like spinach and chocolate, can block calcium absorption. Phytic acid, present in unsoaked grains and seeds, can interfere with absorption as well. Stress can also interfere with the body's ability to assimilate nutrients.

The China Study Findings

In the book The China Study (2005), nutritional biochemist T. Colin Campbell explains the relationship his research has found between animal-based diets and disease, particularly heart disease and certain cancers.

His research provides evidence that plant based diets can:

• Provide the same or similar nutrients as animal-based products


• Help remove toxins from environmental pollutants


• Reduce the risk of many diseases


• Help reverse, slow or halt some existing diseases

Campbell came from a conventional background and began his research career with quite different hypotheses, expecting to find a correlation between meat-based diets and greater health, intelligence and longevity. Instead his work uncovered evidence that people who eat entirely or mostly plant-based diets are healthier and live longer. He also points out that unlike most medicines, nutrition that is designed to assist with a particular disease can help boost the overall health of an individual.

Eight hours of questions and answers with T. Colin Campbell

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