A healthy vegetarian diet falls within the guidelines offered by the USDA. However, meat, fish and poultry are major sources of iron, zinc and B vitamins, so pay special attention to these nutrients. Vegans (those who eat only plant-based food) may want to consider vitamin and mineral supplements; make sure you consume sufficient quantities of protein, vitamin B12, vitamin D and calcium. You can obtain what you need from non-animal sources. For instance:
As with all dietary supplements, in the United States inappropriate label health claims such as preventing or treating disease are opposed by the FDA and deceptive advertisements by the Federal Trade Commission. Probiotic foods and dietary supplements are allowed to make claims using Structure:Function vocabulary as long as human trial evidence is adequate. In 2005, the FDA issued a Warning Letter to UAS Laboratories for disease treatment claims (colds, flu, ulcers, elevated blood cholesterol, colon cancer...). The company revised label and website content and continued to sell the product. In 2011 the company was found to have resumed the label and website claims, and the FDA seized product and stopped production. In 2010 a FTC action was brought against a probiotic food company for exaggerated health claims, resulting in a multimillion-dollar fine and revisions to future advertising. In the European Union a more restrictive approach has been taken by the EFSA. All proposed health claims were rejected on the grounds that the science was not sufficient, and no health claims are permitted. Foods with live microorganisms (yogurt, kefir) can be sold, but without claims.
The need for efficient detoxification and excretion is greatly increased by environmental pollution from the chemical industry, herbicides and pesticides used by industrial agriculture, antibiotic treatment of animals, transport, and plastic packaging.  In our polluted world, the increased toxic load may be compensated for by an increase in nutrients to promote detoxification. One can respond by taking large doses of supplements of essential nutrients, for example, antioxidants vitamin C and E, and an adequate dose of selenium, which help the body detoxify harmful chemicals. Also helpful is regularly taking sauna baths, fasting periodically, and eating an excellent diet that includes generous portions of dark green leafy vegetables and colorful vegetables and fruits. 
Trans fat: Some trans fat is naturally in fatty meat and dairy products. Artificial trans fats have been widely used in packaged baked goods and microwave popcorn. They're bad for heart health, so avoid them as much as possible. Look on the nutrition facts label to see how much trans fat is in an item. Know that something that says "0 g trans fat" may actually have up to half a gram of trans fat in it. So also check the ingredients list: If it mentions "partially hydrogenated" oils, those are trans fats.
Junk foods, however, are designed to avoid this sensory specific response. They provide enough taste to be interesting (your brain doesn’t get tired of eating them), but it’s not so stimulating that your sensory response is dulled. This is why you can swallow an entire bag of potato chips and still be ready to eat another. To your brain, the crunch and sensation of eating Doritos is novel and interesting every time.
Maintaining a healthy weight is important piece of the puzzle to achieve good health. A healthy weight can be determined using the body mass index charts (see web source below). If you find you are overweight or obese, weight loss may be beneficial for you. Before you begin any weight loss efforts, consult with your medical provider and/or consult a registered dietitian to create a weight loss plan. If you are underweight, consult a medical provider to assess your weight status.
Vitamin C protects the brain and nervous system from damage caused by stress because the synthesis and maintenance of chemical neurotransmitters such as adrenaline and noradrenaline requires adequate levels of vitamin C.  Vitamin C is also needed to repair collagen which is essential for skin, blood vessels, bones and joints, and muscles. When these are damaged by physical stress, extra vitamin C is necessary. A controlled trial of 91 adults who experienced increased anxiety and stress 2-3 months after an earthquake in New Zealand in 2011 was divided into three groups, two were given a broad spectrum supplement of micronutrients in low or higher doses.  The supplements were found to alleviate the experience of stress, with the biggest dose having the biggest effect.
Folate is most important for women of childbearing age. If you plan to have children some day, think of folate now. Folate is a B vitamin needed both before and during pregnancy and can help reduce risk of certain serious common neural tube birth defects (which affect the brain and spinal chord). Women ages 15-45 should include folate in their diet to reduce the risk for birth defects if one becomes pregnant, even if one is not planning a pregnancy.
In the same year, the European Food Safety Authority also approved a dietary supplement health claim for calcium and vitamin D and the reduction of the risk of osteoporotic fractures by reducing bone loss. The U.S. FDA also approved Qualified Health Claims (QHCs) for various health conditions for calcium, selenium and chromium picolinate. QHCs are supported by scientific evidence, but do not meet the more rigorous “significant scientific agreement” standard required for an authorized health claim. If dietary supplement companies choose to make such a claim then the FDA stipulates the exact wording of the QHC to be used on labels and in marketing materials. The wording can be onerous: "One study suggests that selenium intake may reduce the risk of bladder cancer in women. However, one smaller study showed no reduction in risk. Based on these studies, FDA concludes that it is highly uncertain that selenium supplements reduce the risk of bladder cancer in women."
For instance, foods rich in vitamin E and beta-carotene are healthy and can help reduce cancer risk. However, the U.S. Preventive Services Task Force (USPSTF) and the American Academy of Family Physicians (AAFP) recommend against taking vitamin E or beta-carotene for the prevention of cardiovascular disease. People who smoke or are at risk for lung cancer also should avoid beta-carotene. It can increase their risk of lung cancer.
This article is only for your information. It is not advice about your health care. You should read the product labels carefully. It is important for you to speak to your doctor or pharmacist before taking any supplement. If you are taking medications, including over-the-counter medications, you should speak to your doctor or pharmacist. If you are taking other supplements, you should speak to your doctor or pharmacist. If you have a medical condition or health problem, or if you are pregnant or nursing, you should speak to your doctor. Consult a healthcare provider immediately if you experience any reactions or side effects.
"Often the enthusiasm for these vitamins and supplements outpaces the evidence. And when the rigorous evidence is available from randomized controlled trials, often the results are at odds with the findings of the observational studies," explains Dr. JoAnn Manson, chief of preventive medicine at Brigham and Women's Hospital, professor of medicine at Harvard Medical School, and principal investigator of a large randomized trial known as VITAL (Vitamin D and Omega-3 Trial).
The Food and Drug Administration (FDA) defines a supplement as “a product taken by mouth that contains a 'dietary ingredient' intended to supplement the diet. The 'dietary ingredients' in these products may include: vitamins, minerals, herbs or other botanicals, amino acids, and substances such as enzymes, organ tissues, glandulars, and metabolites.” Supplements are intended to supplement nutrients missing in your diet, not replace them.
A 2013 study on herbal supplements found that many products were of low quality, one third did not contain the active ingredient(s) claimed, and one third contained unlisted substances. In a genetic analysis of herbal supplements, 78% of samples contained animal DNA that was not identified as an ingredient on the product labels. In some botanical products, undeclared ingredients were used to increase the bulk of the product and reduce its cost of manufacturing, while potentially violating certain religious and/or cultural limitations on consuming animal ingredients, such as cow, buffalo or deer. In 2015, the New York Attorney General identified four major retailers with dietary supplement products that contained fraudulent and potentially dangerous ingredients, requiring the companies to remove the products from retail stores.
Make the right changes. When cutting back on unhealthy foods in your diet, it’s important to replace them with healthy alternatives. Replacing dangerous trans fats with healthy fats (such as switching fried chicken for grilled salmon) will make a positive difference to your health. Switching animal fats for refined carbohydrates, though (such as switching your breakfast bacon for a donut), won’t lower your risk for heart disease or improve your mood.
It’s perfectly OK to indulge in breakfast sausage and cheeseburgers on occasion. But on an everyday basis, there are plenty of great lean proteins to choose from. Some good meat-free options include beans, peas, quinoa, lentils, tofu, low-fat yogurt and 1% milk. Fish is another great source of protein that can also be rich in healthy omega-3’s. As far as meat goes, cuts that have round, chuck or loin in the name are usually leanest, along with chicken and turkey breast. Learn more with our Essential Guide to Protein.
Notice that alcohol isn't included in a food group. If you drink alcohol, do so in moderation, up to one drink per day for women and two drinks per day for men. Alcohol offers little nutritional value, and when used in excess, can cause short-term health damage, such as distorted vision, judgment, hearing and coordination; emotional changes; bad breath; and hangovers. Long-term effects may include liver and stomach damage, vitamin deficiencies, impotence, heart and central nervous system damage and memory loss. Abuse can lead to alcohol poisoning, coma and death. Pregnant women should not drink at all because alcohol can harm the developing fetus and infant. According to the March of Dimes, more than 40,000 babies are born each year with alcohol-related damage. Even light and moderate drinking during pregnancy can hurt your baby. If you are breastfeeding, discuss drinking alcohol with your health care professional. After clearing it with your doctor, you may be able to have an occasional celebratory single, small alcoholic drink, but you should abstain from breastfeeding for two hours after that drink.
The FDA does not have authority over dietary supplements in the same way it does prescription medicines. The Federal Government does not regularly test what is in dietary supplements, and companies are not required to share information on the safety of a dietary supplement with the FDA before they sell it. The companies are responsible for making sure the supplement is safe, but the FDA does not evaluate the safety of the product before the supplement is sold. So, just because you see a dietary supplement on a store shelf does not mean it is safe, that it does what the label says it will, or that it contains what the label says it contains.
Overall diet is an important first consideration for those considering nutritional supplementation. Healthy dietary habits can help optimize nutrition and the absorption of supplements, and nutritional supplements cannot substitute for a diet that is not nutritionally balanced in the first place. Supplements are best used moderately to supply any extra nutritional requirements. Sound diets contain a variety of wholesome foods. At least five servings per day of fruits and vegetables are recommended, as well as the inclusion of whole grains in the diet. Variety in the diet is important to provide a full range of vitamins and minerals. Overeating inhibits digestion and absorption of nutrients, while regular exercise contributes to sound nutrition, by improving metabolism and digestion. Drinking plenty of clean water prevents dehydration, improves digestion, and helps the body flush out impurities.
Substances which the FDA regulates as food are subdivided into various categories, including foods, food additives, added substances (man-made substances which are not intentionally introduced into food, but nevertheless end up in it), and dietary supplements. The specific standards which the FDA exercises differ from one category to the next. Furthermore, the FDA has been granted a variety of means by which it can address violations of the standards for a given category of substances.