SOURCES: Institute of Medicine Food and Nutrition Board, Dietary Reference Intakes: "Calcium, Phosphorus, Magnesium, Vitamin D and Fluoride." National Academy Press, Washington, D.C., 1999. Journal of Nutrition, October 2005. Position paper of the American Dietetic Association on Food Fortification and Supplementation, Journal of the American Dietetic Association, August 2005. Michael Holick, MD, PhD, professor of medicine, physiology, and biophysics, Boston University Medical Center. Andrew Shoa, PhD, vice president for regulatory affairs, Council for Responsible Nutrition. Alice Lichtenstein, DSc, director and senior scientist, Cardiovascular Nutrition Laboratory, Human Nutrition Research Center on Aging, Tufts University. Dave Grotto, RD, spokesman, American Dietetic Association; author, 101 Foods That Could Save Your Life. Eduardo Baetti, MD, rheumatologist; Kaiser Permanente. Patrick Rea, editorial director, Nutrition Business Journal. Kristine Clark, PhD, RD, director of sports nutrition, Penn State University. Vasilios Frankos, PhD, Division of Dietary Supplement Programs, FDA. Sarubin, A. The Health Professionals Guide to Popular Dietary Supplements, American Dietetic Association, Chicago, IL, 2000. FDA. WebMD Weight Loss Clinic Feature: "Are You Getting Enough Vitamin D?" National Center for Complementary and Alternative Medicine: "Questions and Answers About Homeopathy."
Other nutritional supplements include nutrient-dense food products. Examples of these are brewer's yeast, spirulina (sea algea), bee pollen and royal jelly, fish oil and essential fatty acid supplements, colostrum (a specialty dairy product), psyllium seed husks (a source of fiber), wheat germ, wheatgrass, and medicinal mushrooms such as the shiitake and reishi varieties.
Supplements are most likely to cause side effects or harm when people take them instead of prescribed medicines or when people take many supplements in combination. Some supplements can increase the risk of bleeding or, if a person takes them before or after surgery, they can affect the person's response to anesthesia. Dietary supplements can also interact with certain prescription drugs in ways that might cause problems. Here are just a few examples:
Prepare more of your own meals. Cooking more meals at home can help you take charge of what you’re eating and better monitor exactly what goes into your food. You’ll eat fewer calories and avoid the chemical additives, added sugar, and unhealthy fats of packaged and takeout foods that can leave you feeling tired, bloated, and irritable, and exacerbate symptoms of depression, stress, and anxiety.
Overall, one should make sure they are eating well and exercising, and then, speak with a nutritionist or physician trained in nutrition to get advice on which supplements you may need. The best resources are physicians trained in nutrition and are board certified physician nutrition specialists (main.uab.edu/Sites/abpns/) and nutritionists with the credential certified nutrition specialist (CNS) as well as Registered Dietitian (RD).
Herbal supplements are added to the diet for both nutritional and medicinal purposes. Herbs have been used for centuries in many traditional medicine systems, and as sources of phytochemicals, or substances found in plants that have notable effects in the body. Chinese medicine and Ayurvedic medicine from India, two of the world's oldest healing systems, use hundreds of herbal medications. Naturopathy and homeopathy, two other systems of natural healing, also rely on herbal preparations as their main sources of medication. The medicinal effects of herbs are getting scientific validation; about one-fourth of all pharmaceuticals have been derived directly from plant sources, including aspirin (found in willow bark), codeine (from poppy seeds), paclitaxel (Taxol), a patented drug for ovarian and breast cancer (from the Pacific Yew tree), and many others.
The soil in areas with relatively low rainfall may in some cases contain an extremely high concentration of minerals, which is reflected in the plants growing there. This was well documented 70 years ago in the book Tomorrow's Food.  The Dentist George W. Heard found that the soil in Hereford, Texas, was exceptionally rich in minerals. Hereford became known as the "town without a toothache" after a newspaper article from January 29, 1942, reported that Hereford had the lowest incidence of tooth decay of any city in the United States.  Heard found that people in Hereford had exceptionally few dental cavities and also that the soil locally was especially rich in minerals. He emphasized that the population in the county ate unprocessed food and was drinking raw milk. 
Dynamic contrast. Dynamic contrast refers to a combination of different sensations in the same food. In the words of Witherly, foods with dynamic contrast have “an edible shell that goes crunch followed by something soft or creamy and full of taste-active compounds. This rule applies to a variety of our favorite food structures — the caramelized top of a creme brulee, a slice of pizza, or an Oreo cookie — the brain finds crunching through something like this very novel and thrilling.”
As continual research on the properties of supplements accumulates, databases or fact sheets for various supplements are updated regularly, including the Dietary Supplement Label Database, Dietary Supplement Ingredient Database, and Dietary Supplement Facts Sheets of the United States. In Canada where a license is issued when a supplement product has been proven by the manufacturer and government to be safe, effective and of sufficient quality for its recommended use, an eight-digit Natural Product Number is assigned and recorded in a Licensed Natural Health Products Database. The European Food Safety Authority maintains a compendium of botanical ingredients used in manufacturing of dietary supplements.
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.