Vegetarian diets have many advantages, including higher fiber, more antioxidants such as vitamin A, vitamin C and vitamin E, and lower saturated fats, animal proteins and cholesterol. However, there are a number of nutritional concerns. A good vegetarian diet should have a balanced combination of proteins, iron, calcium, vitamin B-12 and omega-3 fatty acids, which tend to be inadequate in vegetarian diets.
Proteins
Vegetarians may have higher protein requirements than non-vegetarians so you should carefully plan your daily protein intake. Plant proteins are less digestible and often lack one or more essential amino acids, which are the basic units that you body needs from diet to make proteins. Vegans -- who exclude all animal foods, including eggs, fish and dairy products -- may have protein needs that are 15 to 20 percent higher than non-vegetarians. Grain proteins like those in cereals are often low in the essential amino acid lysine. You can complement this with the lysine from soy foods and legumes such as beans, peas and lentils.
Iron
You should incorporate more iron-rich foods such as beans, lentils, soybeans and oatmeal into your diet. Vegetarian diets contain a less absorbable form of iron called non-heme iron while presenting more challenges for iron absorption. Plant foods contain more phytate, which inhibits the absorption of non-heme iron. Vegetarians need almost twice as much iron as non-vegetarians, according to the American Dietetic Association. Eating plenty of fresh fruits and vegetables helps with iron intake because vitamin C and organic acids in these foods increase iron absorption. Additionally, avoid drinking tea, cocoa and coffee or taking calcium supplements with meals because these foods inhibit iron absorption.
Calcium
Many plant foods have highly absorbable calcium. For example, more than 50 percent of the calcium in cruciferous vegetables like broccoli, bok choy, Chinese cabbage and kale can be absorbed, compared to the 30 percent absorption rate of calcium in milk. However, the phytate and oxalate in plant foods tend to inhibit calcium absorption. Plan at least eight servings per day of calcium-rich foods such as cruciferous vegetables, tofu, figs, almonds, sesame seeds, soy beans, soy nuts, white and red beans, and calcium-fortified juices or soy milk to meet your calcium requirements.
Vitamin B-12
Pay close attention to vitamin B12 in your diet because no plant food provides a reliable source of vitamin B-12. If your vitamin B-12 status is not optimal, supplements or fortified foods may help. If you are a lacto-ovo vegetarian, dairy products and eggs provide additional source of vitamin B-12. Frequent consumption of small amounts of vitamin B-12 increases its absorption. For example, you can eat small amount of vitamin B12-fortified foods several times a day to maximize the intake.
Omega-3 Fatty Acids
Vegetarian foods have higher omega-6 fatty acids but tend to be low in omega-3 fatty acids, especially eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA. Flaxseeds, flaxseed oil, walnuts, walnut oil and canola oil provide omega-3 fatty acid precursors that can be converted to EPA and DHA in your body. But the conversion is inefficient. Sea vegetables like algae make DHA that is directly usable to humans. You can add algae supplements to your diet as a vegetarian source of DHA. The World Health Organization recommends 2.2 to 4.4 g of omega-3 fatty acids a day for a standard 2,000-calorie diet.
Member Comments