Getting adequate nutrition
The key to a healthy vegetarian diet — like any diet — is to enjoy a variety of foods. No single food can provide all the nutrients your body needs. The more restrictive your diet is, the more challenging it can be to get all the nutrients you need. A vegan diet, for example, eliminates natural food sources of vitamin B-12, as well as milk products, which are good sources of calcium.
With a little planning, however, you can be sure that your diet includes everything your body needs. Pay special attention to the following nutrients:
- Calcium helps build and maintain strong teeth and bones. Milk and dairy foods are highest in calcium. However, dark green vegetables, such as turnip and collard greens, kale and broccoli, are good plant sources when eaten in sufficient quantities. Calcium-enriched and fortified products, including juices, cereals, soy milk, soy yogurt and tofu, are other options.
- Iodine is a component in thyroid hormones, which help regulate metabolism, growth and function of key organs. Vegans may not get enough iodine and be at risk of deficiency and possibly even a goiter. In addition, foods such as soybeans, cruciferous vegetables and sweet potatoes may promote a goiter. However, just 1/4 teaspoon of iodized salt provides a significant amount of iodine.
- Iron is a crucial component of red blood cells. Dried beans and peas, lentils, enriched cereals, whole-grain products, dark leafy green vegetables and dried fruit are good sources of iron. Because iron isn't as easily absorbed from plant sources, the recommended intake of iron for vegetarians is almost double that recommended for nonvegetarians. To help your body absorb iron, eat foods rich in vitamin C, such as strawberries, citrus fruits, tomatoes, cabbage and broccoli, at the same time as you're eating iron-containing foods.
- Omega-3 fatty acids are important for heart health. Diets that do not include fish and eggs are generally low in active forms of omega-3 fatty acids. Canola oil, soy oil, walnuts, ground flaxseed and soybeans are good sources of essential fatty acids. However, because conversion of plant-based omega-3 to the types used by humans is inefficient, you may want to consider fortified products or supplements, or both.
- Protein helps maintain healthy skin, bones, muscles and organs. Eggs and dairy products are good sources, and you don't need to eat large amounts to meet your protein needs. You can also get sufficient protein from plant-based foods if you eat a variety of them throughout the day. Plant sources include soy products and meat substitutes, legumes, lentils, nuts, seeds and whole grains.
- Vitamin B-12 is necessary to produce red blood cells and prevent anemia. This vitamin is found almost exclusively in animal products, so it can be difficult to get enough B-12 on a vegan diet. Vitamin B-12 deficiency may go undetected in people who eat a vegan diet. This is because the vegan diet is rich in a vitamin called folate, which may mask deficiency in vitamin B-12 until severe problems occur. For this reason, it's important for vegans to consider vitamin supplements, vitamin-enriched cereals and fortified soy products.
- Vitamin D plays an important role in bone health. Vitamin D is added to cow's milk, some brands of soy and rice milk, and some cereals and margarines. Be sure to check food labels. If you don't eat enough fortified foods and have limited sun exposure, you may need a vitamin D supplement (one derived from plants).
- Zinc is an essential component of many enzymes and plays a role in cell division and in formation of proteins. Like iron, zinc is not as easily absorbed from plant sources as it is from animal products. Cheese is a good option if you eat dairy products. Plant sources of zinc include whole grains, soy products, legumes, nuts and wheat germ.
If you need help creating a vegetarian diet that's right for you, talk with your doctor and a registered dietitian.
If you're not following a vegetarian diet but you're thinking of trying it, here are some ideas to help you get started:
July 11, 2012
- Ramp up. Each week increase the number of meatless meals you already enjoy, such as spaghetti with tomato sauce or vegetable stir-fry.
- Learn to substitute. Take favorite recipes and try them without meat. For example, make vegetarian chili by leaving out the ground beef and adding an extra can of black beans. Or make fajitas using extra-firm tofu rather than chicken. You may be surprised to find that many dishes require only simple substitutions.
- Branch out. Scan the Internet for vegetarian menus. Buy or borrow vegetarian cookbooks. Check out ethnic restaurants to sample new vegetarian cuisines. The more variety you bring to your vegetarian diet, the more likely you'll be to meet all your nutritional needs.
See more In-depth
- Messina V, et al. A new food guide for North American vegetarians. Journal of the American Dietetic Association. 2003;103:748.
- Vegetarian diets. American Heart Association. http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/Vegetarian-Diets_UCM_306032_Article.jsp. Accessed June 5, 2012.
- Duyff RL. American Dietetic Association Complete Food and Nutrition Guide. 4th ed. Hoboken, N.J.: John Wiley & Sons; 2012:254.
- Position of the American Dietetic Association: Vegetarian diets. Journal of the American Dietetic Association. 2009;109:1266.
- Marsh K, et al. Meeting nutritional needs on a vegetarian diet. Australian Family Physician. 2009;38:600.
- Dietary Guidelines for Americans, 2010. U.S. Department of Health and Human Services. http://www.cnpp.usda.gov/DGAs2010-PolicyDocument.htm. Accessed June 5, 2012.
- Craig WJ. Nutrition concerns and health effects of vegetarian diets. Nutrition in Clinical Practice. 2010;25:613.
- Craig WJ. Health effects of vegan diets. American Journal of Clinical Nutrition. 2009;89:1627S.