^ Siscovick DS, Barringer TA, Fretts AM, Wu JH, Lichtenstein AH, Costello RB, Kris-Etherton PM, Jacobson TA, Engler MB, Alger HM, Appel LJ, Mozaffarian D (2017). "Omega-3 Polyunsaturated Fatty Acid (Fish Oil) Supplementation and the Prevention of Clinical Cardiovascular Disease: A Science Advisory From the American Heart Association". Circulation. 135 (15): e867–e884. doi:10.1161/CIR.0000000000000482. PMID 28289069.
Creating an industry estimated to have a 2015 value of $37 billion, there are more than 50,000 dietary supplement products marketed just in the United States, where about 50% of the American adult population consumes dietary supplements. Multivitamins are the most commonly used product. For those who fail to consume a balanced diet, the United States National Institutes of Health states that certain supplements "may have value."
Processing of food reduces its nutritional content, and the finished products are often based on fractions of the original foods. One example is milling grain to make white flour,  which has a lower nutritional density than whole grain flour. The reduction in nutritional value has accelerated since whole foods are now divided into pieces, for example, boneless chicken breast. When meat is injected with saline to increase the volume, the relative level of essential nutrients is reduced. In the United States, many supermarkets in low-income rural and inner city areas have a limited selection of nutrient-dense foods, compared with high-income areas. 
Although as a general rule, dietary supplement labeling and marketing are not allowed to make disease prevention or treatment claims, the U.S. FDA has for some foods and dietary supplements reviewed the science, concluded that there is significant scientific agreement, and published specifically worded allowed health claims. An initial ruling allowing a health claim for calcium dietary supplements and osteoporosis was later amended to include calcium supplements with or without vitamin D, effective January 1, 2010. Examples of allowed wording are shown below. In order to qualify for the calcium health claim, a dietary supplement much contain at least 20% of the Reference Dietary Intake, which for calcium means at least 260 mg/serving.
Trying to balance the demands of family and work or school—and coping with media pressure to look and eat a certain way—can make it difficult for any woman to maintain a healthy diet. But the right food can not only support your mood, boost your energy, and help you maintain a healthy weight, it can also be a huge support through the different stages in a woman’s life. Healthy food can help reduce PMS, boost fertility, make pregnancy and nursing easier, ease symptoms of menopause, and keep your bones strong. Whatever your age or situation, committing to a healthy, nutritious diet will help you look and feel your best and get the most out of life.
^ Wilson, RD; Committee, Genetics; Wilson, RD; Audibert, F; Brock, JA; Carroll, J; Cartier, L; Gagnon, A; Johnson, J. A; Langlois, S; Murphy-Kaulbeck, L; Okun, N; Pastuck, M (2015). "Pre-conception Folic Acid and Multivitamin Supplementation for the Primary and Secondary Prevention of Neural Tube Defects and Other Folic Acid-Sensitive Congenital Anomalies" (PDF). Journal of Obstetrics and Gynaecology Canada. 37 (6): 534–552. PMID 26334606.
Another spin on the 80/20 rule, says Dr. Lipman: stopping eating when you're 80% full. That means slowing down and checking in periodically throughout the meal about what your body is saying. Does the food no longer taste great? Are you getting that "I don't really need any more feeling"? Thinking 80/20 as you eat can help slow you down and be more mindful. Being in tune with your body prevents overeating, he says.
Some supplements that were found to have health benefits in observational studies turned out, with more rigorous testing, to be not only ineffective but also risky. Vitamin E, which was initially thought to protect the heart, was later discovered to increase the risk for bleeding strokes. Folic acid and other B vitamins were once believed to prevent heart disease and strokes—until later studies not only didn't confirm that benefit but actually raised concerns that high doses of these nutrients might increase cancer risk.
Use MyPlate (PDF – 281 KB) as a guide to build a healthy diet. Think about filling your plate with foods from the five food groups — fruits, vegetables, grains, proteins, and dairy — at each meal. Snacks can be a good way to fill in fruits and whole grains you might have missed at meals. Most of us don’t need complicated calorie counting programs or special recipes for healthy eating.
When shopping for an herbal supplement, it's important to verify which parts of the plant were used in its production. Different components can produce different effects, some of which can harm your health. For example, research shows that while the roots of the herb kava seem to be safe, its stem peelings and leaves may contain compounds that could be toxic to the liver. Talking with your doctor or herbalist can help you determine which plant parts to look for.
Actually, more people suffer from food intolerances, which don't involve the immune system. However, food intolerance symptoms—such as intestinal distress—may mimic those of a food allergy. If you have a food intolerance, talk to a nutritionist about diagnosis and treatment; if you have food allergies, you need to see an allergist. Whether you have food allergies or intolerance, you will need to develop a diet that fits your needs and avoids foods that trigger a reaction.
Getting enough water also is important. Many experts recommend at least eight 8-ounce glasses of water daily—more if you exercise frequently or are exposed to extremes of heat and cold. The 2010 Dietary Guidelines for Americans emphasize drinking more water and other calorie-free beverages, along with fat-free or low-fat milk and 100 percent fruit juices, instead of calorie-packed regular sodas.
Herbal preparations and nutritional supplements may interact unfavorably with pharmaceutical drugs. For instance, some nutritional supplements recommended for nervous system function may not be recommended for those taking pharmaceutical antidepressants, such as taking 5-HTP, a nutritional supplement for the brain, or the herb St. John's Wort, with prescription antidepressants. Vitamin C should not be taken with aspirin, as it can irritate the stomach and limit absorption. Minerals should be taken in proper proportions to prevent unfavorable interactions; large amounts of zinc may deplete the body of the mineral copper, while too much calcium adversely affects the magnesium levels in the body. Balanced mineral supplements are recommended to alleviate these interactions.
Dietary supplement labels may carry certain types of health-related claims. Manufacturers are permitted to say, for example, that a dietary supplement addresses a nutrient deficiency, supports health, or is linked to a particular body function (like immunity or heart health). Such a claim must be followed by the words, "This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease."
Don’t fear the fats! Healthy fats provide the structural component to many cell membranes which are essential for cellular development and carrying various messages (hormones) through our body quickly. Protein is also responsible for hormone production, so it’s important for women to get foods that will provide you with healthy fats and protein. Women’s cycles can also deplete your body of B vitamins, iron, zinc, and magnesium so you should be aware of your whole food intake and possibly choose to supplement (see above for more if it’s right for you).
Grains, vegetables and fruits are essential to getting the vitamins, minerals, complex carbohydrates (starch and dietary fiber) and other nutrients you need to sustain good health. Some of these nutrients may even reduce your risk of certain kinds of cancer. But experts say we rarely eat enough of these foods. To make matters worse, we also eat too much of unhealthy types of food, including fat (and cholesterol), sugar and salt.
Dietary supplements can be manufactured using intact sources or extracts from plants, animals, algae, fungi or lichens, including such examples as ginkgo biloba, curcumin, cranberry, St. John’s wort, ginseng, resveratrol, glucosamine and collagen. Products bearing promotional claims of health benefits are sold without requiring a prescription in pharmacies, supermarkets, specialist shops, military commissaries, buyers clubs, direct selling organizations, and the internet. While most of these products have a long history of use in herbalism and various forms of traditional medicine, concerns exist about their actual efficacy, safety and consistency of quality. Canada has published a manufacturer and consumer guide describing quality, licensing, standards, identities, and common contaminants of natural products. In 2016, sales of herbal supplements just in the United States were $7.5 billion, with the market growing at about 8% per year. Italy, Germany and Eastern European countries were leading consumers of botanical supplements in 2016, with European Union market growth forecast to be $8.7 billion by 2020.
Part of the reason why so many women fail to get the amount of iron they need is because one of the best sources of iron is red meat (especially liver) which also contains high levels of saturated fat. While leafy green vegetables and beans are also good sources of iron—and don’t contain high levels saturated fat—the iron from plant foods is different to the iron from animal sources, and not absorbed as well by the body. Other foods rich in iron include poultry, seafood, dried fruit such as raisins and apricots, and iron-fortified cereals, breads, and pastas.