A vegetarian diet focuses on plants for food. These include fruits, vegetables, dried beans and peas, grains, seeds and nuts. There is no single type of vegetarian diet. Instead, vegetarian eating patterns usually fall into the following groups:

• The vegan diet, which excludes all meat and animal products
• The lacto vegetarian diet, which includes plant foods plus dairy products
• The lacto-ovo vegetarian diet, which includes both dairy products and eggs

People who follow vegetarian diets can get all the nutrients they need. However, they must be careful to eat a wide variety of foods to meet their nutritional needs. Nutrients vegetarians may need to focus on include protein, iron, calcium, zinc and vitamin B12.

Vegetarians miss out on lots of foods. No grilled burgers or franks at picnics. No holiday turkey or fries cooked in animal fat. Strict vegetarians may even forego honey made by bees. But vegetarians also tend to miss out on major health problems that plague many Americans. They generally live longer than the rest of us, and they’re more likely to bypass heart-related and other ailments.

The fact is, eating a more plant-based diet can boost your health, whether you’re a vegetarian or not.

What is it about the vegetarian lifestyle that can protect your health? And are there risks to being vegetarian? NIH-funded researchers are looking for answers. They’re exploring the many ways that diet and other factors affect our health.

Vegetarian meals focus on fruits and vegetables, dried beans, whole grains, seeds and nuts. By some estimates, about 2% of the U.S. adult population follows this type of diet.

People have many reasons for becoming vegetarians. Some want to eat more healthy foods. Others have religious or economic reasons or are concerned about animal welfare. “Vegetarian diets are also more sustainable and environmentally sound than diets that rely heavily on meat, poultry and fish,” says NIH nutritionist Dr. Susan Krebs-Smith, who monitors trends in cancer risk factors.

Most people think of vegetarian diets as simply eating plant foods and not eating meat, poultry and fish. “But in fact, there are many different types of vegetarian diets,” Krebs-Smith explains. “Some are more restrictive than others.”

Strict vegetarians, or vegans, eat plant foods and reject all animal products—meat, poultry, fish, eggs, dairy and sometimes honey. Those who also eat dairy products are called lacto vegetarians. Vegetarians who eat both dairy and eggs are called lacto-ovo vegetarians.

Some vegetarians eat fish but not meat or poultry. They’re called pescatarians (pesce is Italian for fish).

“Then there are the so-called flexitarians, or semi-vegetarians. These are people who eat a mostly vegetarian diet, but they occasionally eat meat,” says Jody Engel, a nutritionist and registered dietitian at NIH. “They might say ‘I’m a vegetarian, but I need to eat my burgers every Sunday.’ People tend to follow their own rules, which is one reason why it’s hard for researchers to study vegetarians. There’s so much variance.”

Despite the different definitions, “there’s tremendous agreement among nutrition experts and health organizations that a more plant-based diet is beneficial, whether you’re a true vegetarian or not,” says Krebs-Smith. “Most Americans don’t eat enough fruit, vegetables, legumes or whole grains. There’s a huge consensus that eating more of these foods would be a good idea for everyone.”

Vegetarian diets tend to have fewer calories, lower levels of saturated fat and cholesterol, and more fiber, potassium and vitamin C than other eating patterns. Vegetarians tend to weigh less than meat-eaters, and to have lower cancer rates. “Evidence also suggests that a vegetarian diet is associated with a lower risk of death from certain heart diseases, and that those who follow a vegetarian diet tend to have lower LDL [“bad”] cholesterol levels,” says Engel.

In some cases, though, it’s unclear if certain health benefits come from plant-based eating or from the healthy lifestyle of most vegetarians. “Vegetarians are generally more physically active and have healthier habits than non-vegetarians. They also typically have a higher socioeconomic status, at least in the United States,” says Krebs-Smith.

To tease out the effects of diet, scientists have to conduct large, carefully controlled studies that account for other factors. One of the world’s largest studies of plant-based diets is now underway at Loma Linda University in California. Cardiologist Dr. Gary Fraser is leading an NIH-funded team of scientists to analyze data on 96,000 Seventh-day Adventists in all 50 states and in Canada. Members of this religious group have unique dietary habits and a generally healthy lifestyle.

Adventists are encouraged to follow a vegetarian diet, but about half the population sometimes eats meat. These variable eating patterns allow scientists to compare a wide range of dietary habits and look for links between diet and disease.

To date, the researchers have found that the closer people are to being vegetarian, the lower their risk of diabetes, high blood pressure and metabolic syndrome (a condition that raises your risk for heart disease and stroke). “The trend is almost like a stepladder, with the lowest risks for the strict vegetarians, then moving up for the lacto vegetarians and then the pescatarians and then the non-vegetarians,” Fraser explains. Earlier studies found that vegetarian Adventists also tend to live longer than both meat-eating Adventists and non-Adventists. The vegetarians also have less coronary heart disease and lower rates of some cancers.

Because vegetarians by definition don’t eat meat, some people jump to the conclusion that simply cutting meat from your diet will lead to health benefits. “But it’s actually more complicated than that,” says Fraser. “Differences in life expectancy and other health matters might be related to the extra fruits, vegetables, nuts and legumes—including soy—that vegetarians tend to eat. You can’t necessarily conclude it’s based on the absence of meat,” he says.

Experts generally agree that vegetarians who eat a wide variety of foods can readily meet all their body’s needs for nutrients. “At any stage of life, you should be able to eat a healthy diet by consuming vegetarian foods. But it does take a little planning,” says Rachel Fisher, a registered dietitian involved in nutrition research at NIH.

Vegetarians need to be sure they take in enough iron, calcium, zinc and vitamin B12. Studies show that most vegetarians do get enough, in part because so many cereals, breads and other foods are fortified with these nutrients. “Vegans in particular need to be certain to get enough vitamin B12 and omega-3 fatty acids,” says Fisher. Omega-3—found in fish, flax seed, walnuts and canola oil—is important for heart health and vision.

Some vegetarians take dietary supplements to make sure they’re getting everything they need. It’s a good idea to talk to a registered dietitian or other health professional if you’re a vegetarian or thinking of becoming one.

Whether you’re a vegetarian or not, Fisher says, you can benefit from the high fiber, low fat and rich nutrients of a vegetarian diet. “Vegetarian foods can be so delicious, and they’re so good for you,” she says.

Try using a variety of spices and herbs to make things interesting. And make sure not to overcook your vegetables, or they might lose some of their valuable nutrients.

Tips for a Vegetarian Diet

• Meet protein needs by eating a variety of plant foods, nuts, eggs or dairy foods.
• Snack on unsalted nuts and use them in salads or main dishes.
• Vitamin B12 is naturally found only in animal products. Choose fortified foods such as cereals or soy products, or take a vitamin B12 supplement if you don’t eat animal products.
• Get calcium from dairy products and calcium-fortified soy milk, breakfast cereals or orange juice.
• Beans and peas have many nutrients and are recommended for everyone, vegetarians and non-vegetarians alike.

A vegetarian is someone who does not eat meat. Some vegetarians, called vegans, do not eat any animal products, such as eggs or milk. If you are a vegetarian or vegan, you may need to take a dietary supplement, especially if you are pregnant or breastfeeding.

What is a healthy eating plan for women who are vegetarian?

A healthy eating pattern for women who are vegetarian is the same as for any woman. Because vegetarians eat mostly plant-based foods, they usually get more fiber-rich foods and low-cholesterol foods than non-vegetarians do. But women who are vegetarians still need to make sure they are eating healthy, which includes foods with calcium and protein.

Do women who are vegetarian need to take a dietary supplement?

Not always. You can get all the nutrients you need from a vegetarian eating plan by eating a variety of foods from all of the food groups. But you may need to take extra steps to get enough protein, iron, calcium, vitamin B-12, and zinc.

The extra steps you need to take depend on what type of vegetarian you are. For example, low-fat and fat-free milk and milk products are good sources of calcium, vitamin B-12, and complete protein. Eggs are a good source of vitamin B-12, choline, and complete protein. So if you don’t drink milk or eat eggs, you need to get these nutrients from other foods.

Do vegetarians need more nutrients during pregnancy?

Yes. Just like all women, your body needs more of some nutrients, such as folic acid, during pregnancy to help your baby grow and develop. In general, though, choosing a variety of healthy foods from each of the food groups will help you get the nutrients you need during pregnancy. Be sure to get enough protein, found in beans, nuts, nut butters, and eggs if you eat them. See the resources below for vegetarian sources of important nutrients for women.

If you follow a vegan diet or one that does not include any forms of animal protein, you or your baby might not get enough vitamin B₁₂.

In a baby, B₁₂ deficiency can cause symptoms such as:

• Loss of appetite
• Slow motor development
• Being very tired
• Weak muscles
• Vomiting
• Blood problems

You can protect your and your baby's health by taking vitamin B₁₂ supplements while breastfeeding. Talk to your doctor about your vitamin B₁₂ needs.

When you reach for that bottle of vitamin C or fish oil pills, you might wonder how well they’ll work and if they’re safe. The first thing to ask yourself is whether you need them in the first place.

More than half of all Americans take one or more dietary supplements daily or on occasion. Supplements are available without a prescription and usually come in pill, powder or liquid form. Common supplements include vitamins, minerals and herbal products, also known as botanicals.

People take these supplements to make sure they get enough essential nutrients and to maintain or improve their health. But not everyone needs to take supplements.

“It’s possible to get all of the nutrients you need by eating a variety of healthy foods, so you don’t have to take one,” says Carol Haggans, a registered dietitian and consultant to NIH. “But supplements can be useful for filling in gaps in your diet.”

Some supplements may have side effects, especially if taken before surgery or with other medicines. Supplements can also cause problems if you have certain health conditions. And the effects of many supplements haven’t been tested in children, pregnant women and other groups. So talk with your health care provider if you’re thinking about taking dietary supplements.

“You should discuss with your doctor what supplements you’re taking so your care can be integrated and managed,” advises Dr. Craig Hopp, an expert in botanicals research at NIH.

Dietary supplements are regulated by the U.S. Food and Drug Administration (FDA) as foods, not as drugs. The label may claim certain health benefits. But unlike medicines, supplements can’t claim to cure, treat or prevent a disease.

“There’s little evidence that any supplement can reverse the course of any chronic disease,” says Hopp. “Don’t take supplements with that expectation.”

Evidence does suggest that some supplements can enhance health in different ways. The most popular nutrient supplements are multivitamins, calcium and vitamins B, C and D. Calcium supports bone health, and vitamin D helps the body absorb calcium. Vitamins C and E are antioxidants—molecules that prevent cell damage and help to maintain health.

Women need iron during pregnancy, and breastfed infants need vitamin D. Folic acid—400 micrograms daily, whether from supplements or fortified food—is important for all women of childbearing age.

Vitamin B12 keeps nerve and blood cells healthy. “Vitamin B12 mostly comes from meat, fish and dairy foods, so vegans may consider taking a supplement to be sure to get enough of it,” Haggans says.

Research suggests that fish oil can promote heart health. Of the supplements not derived from vitamins and minerals, Hopp says, “fish oil probably has the most scientific evidence to support its use.”

The health effects of some other common supplements need more study. These include glucosamine (for joint pain) and herbal supplements such as echinacea (immune health) and flaxseed oil (digestion).

Many supplements have mild effects with few risks. But use caution. Vitamin K, for example, will reduce the ability of blood thinners to work. Ginkgo can increase blood thinning. The herb St. John’s wort is sometimes used to ease depression, anxiety or nerve pain, but it can also speed the breakdown of many drugs—such as antidepressants and birth control pills—and make them less effective.

Just because a supplement is promoted as “natural” doesn’t necessarily mean it’s safe. The herbs comfrey and kava, for example, can seriously damage the liver.

“It’s important to know the chemical makeup, how it’s prepared, and how it works in the body—especially for herbs, but also for nutrients,” says Haggans. “Talk to a health care provider for advice on whether you need a supplement in the first place, the dose and possible interactions with medicine you’re already taking.”

For vitamins and minerals, check the % Daily Value (DV) for each nutrient to make sure you’re not getting too much. “It’s important to consider the DV and upper limit,” says Haggans. Too much of certain supplements can be harmful.

Scientists still have much to learn even about common vitamins. One recent study found unexpected evidence about vitamin E. Earlier research suggested that men who took vitamin E supplements might have a lower risk of developing prostate cancer. “But much to our surprise, a large NIH-funded clinical trial of more than 29,000 men found that taking supplements of vitamin E actually raised—not reduced—their risk of this disease,” says Dr. Paul M. Coates, director of NIH’s Office of Dietary Supplements. That’s why it’s important to conduct clinical studies of supplements to confirm their effects.

Because supplements are regulated as foods, not as drugs, the FDA doesn’t evaluate the quality of supplements or assess their effects on the body. If a product is found to be unsafe after it reaches the market, the FDA can restrict or ban its use.

Manufacturers are also responsible for the product’s purity, and they must accurately list ingredients and their amounts. But there’s no regulatory agency that makes sure that labels match what’s in the bottles. You risk getting less, or sometimes more, of the listed ingredients. All of the ingredients may not even be listed.

A few independent organizations conduct quality tests of supplements and offer seals of approval. This doesn’t guarantee the product works or is safe; it just assures the product was properly made and contains the listed ingredients.

“Products sold nationally in the stores and online where you usually shop should be fine,” Coates says. “According to the FDA, supplement products most likely to be contaminated with pharmaceutical ingredients are herbal remedies promoted for weight loss and for sexual or athletic performance enhancement.”

To make it easy to find reliable information, NIH has fact sheets on dietary supplements at ods.od.nih.gov/factsheets/list-all/. NIH also recently launched an online Dietary Supplement Label Database at www.dsld.nlm.nih.gov. This free database lets you look up the ingredients of thousands of dietary supplements. It includes information from the label on dosage, health claims and cautions.

For more personalized, on-the-go information about dietary supplements, check out NIH’s free updated app for your smart phone or tablet: My Dietary Supplements (MyDS).

The MyDS app provides the latest supplement information and lets you keep track of the vitamins, minerals, herbs and other products you take. You can even keep track of supplements taken by your parents, spouse or children.

“Deciding whether to take dietary supplements and which ones to take is a serious matter,” says Coates. “Learn about their potential benefits and any risks they may pose first. Speak to your health care providers about products of interest and decide together what might be best for you to take, if anything, for your overall health.”

Safe Use of Supplements

• Tell all of your health care providers about any dietary supplements you use. Some supplements can interact with medications or affect medical conditions.
• Read the label instructions for use.
• “Natural” doesn’t always mean safe. For up-to-date news about the safety of particular supplements, check nccam.nih.gov/news/alerts.
• Too much might be harmful. Don’t take more than the recommended dose.

Healthy eating is important at every age. Eat a variety of fruits, vegetables, grains, protein foods, and dairy or fortified soy alternatives. When deciding what to eat or drink, choose options that are full of nutrients and limited in added sugars, saturated fat, and sodium. Start with these tips:

Make simple changes

Create main dishes such as pasta primavera with vegetables and chickpeas, pizza topped with vegetables, veggie lasagna, tofu-vegetable stir-fry, and spicy bean burritos.

Think about plant-based protein

Eat a variety of plant protein foods such as black or kidney beans, cooked split peas, and yellow or green lentils. Nuts and seeds are also great options to help you meet protein needs.

Build strong bones with calcium

If you skip dairy, get calcium from fortified products like soy beverages, tofu, and some breakfast cereals and orange juices. Dark-green leafy vegetables like collard greens, spinach, and kale are sources of calcium, too.

Add nuts to your day

Choose unsalted nuts as a snack, or use them in salads or main dishes to bump up your protein, dietary fiber, and healthy fats. Slivered almonds or crushed walnuts are great on a green salad.

Have beans for dinner or lunch

Try a bean-based chili, three bean salad, or split pea soup. Beans, peas, and lentils, which are excellent sources of protein, fiber, folate, and several minerals, are recommended for everyone – vegetarians and nonvegetarians alike – because of their high nutrient content.

Enjoy a vegetarian snack

Snack on raw veggies and hummus – a Middle Eastern dip made from blended chickpeas (garbanzo beans). Hummus is rich in protein, dietary fiber, and several important minerals.

The benefits of healthy eating add up over time, bite by bite.