Vegetarian diets typically lack protein, iron, calcium, zinc, vitamin B12, and possibly vitamin D, but are high in fibre, complex carbohydrates, and nutrient rich. If the vegetarian diet is composed mainly of whole grains, legumes, beans, vegetables, fruits, nuts and seeds then it will provide all the nutrients a vegetarian needs.
Vegetarians who include eggs and milk products in their diet can meet most nutrient requirements, especially protein. The protein of whole grains, legumes, seeds, nuts and vegetables can provide adequate amounts of all the amino acids, but should be combined appropriately in order to obtain a complete protein. Please see protein combining for more information. 50 g of protein should be consumed daily. Milk, cheese, butter and eggs are complete proteins so can be consumed alone.
Those who do not eat meat should pay close attention to their iron intake, especially women who are in their menstruating years. The iron in legumes, cereals, fortified cereals and whole grains is not readily absorbed. Iron absorption is enhanced by vitamin C. Requirements are 15 – 20 mg per day. Other sources are: dried beans, dried fruit, spinach, chard, beet greens, blackstrap molasses, prunes and legumes. Cooking in iron cookware increases iron intake. For further reading click on the following links iron deficiency or sources of iron.
Vegetarians who do not consume eggs and milk products are at risk of deficiency. Calcium is especially important for children and post-menopausal women. Calcium is found in nuts, broccoli, tofu, soybeans, molasses, all dairy products, seeds especially sesame seeds, tahini is a high source of calcium. Calcium fortified soy milk can help to increase levels. Sources of calcium contains more information on calcium absorbtion and foods.
Meat is one of the riches sources of zinc, and unfermented soy products can interfere with zinc absorption, hence vegetarians are often low in zinc. Requirements per day are 20 – 25 mg. It becomes necessary for vegetarians to consume a variety of nutrient dense foods rich in zinc such as legumes, e.g. black eyed peas, pinto beans and kidney beans. Zinc can also be found in pumpkin and sunflower seeds, mushrooms, fermented soy products, and eggs also see sources of zinc .
Vitamin B12 is mainly found in animal products, so is present in dairy products and eggs. Some plant foods contain traces of B12 but usually as a B12 analogue that cannot be absorbed by the body, so supplementation may be necessary. Tempeh, miso and brewers yeast contain small amounts of B12, and some seaweeds such as kombu, wakame, kelp, alaria, dulse and nori, and spirulina, chlorella and wild blue green algae (these also have a high amino acid profile, that is – a high protein content).
This is not such a problem in South Africa because we have adequate sunshine, exposure to sunlight helps the synthesis of vitamin D in our bodies. Vitamin D may be lacking in climates where there is less sunshine. If you are vegetarian and do not like the sun then you may well be deficient as the most common food sources are contained in animal products, click on the following link sources of vitamin D for some options.