"Creatine is one of the most popular supplements, with over 100 studies consistently showing it can work in muscle cell recovery in athletes who engage in high-intensity, short-burst activity such as sprinting or weight lifting," notes Clark. "But it does not work for endurance or recreational athletics." (She cautions anyone taking creatine to be sure they stay well hydrated to avoid cramping.)
If you suspect that you have had a serious reaction from a dietary supplement, let your health care provider know. He or she may report your experience to the FDA. You may also submit a report to the FDA by calling 800-FDA-1088 or completing a form online. In addition, report your reaction to the dietary supplement company by using the contact information on the product label.
A visit to the health food store can be an overwhelming experience. It's tough to figure out what to choose from among the dizzying assortment of dietary and nutritional supplements on the shelf. From vitamins to minerals to weight loss pills, there are thousands of options to choose from. But do you really need any of them? Do they really work, and if so, which ones are best?
After 40, your hormone levels (estrogen) drop. This causes your insulin (hormone that helps your body use sugar) rise. Your thyroid levels go down. This combination makes you hungrier. You end up eating more and burning fewer calories. Much of the weight gain occurs around your belly. Eat more foods with fiber (berries, whole grains, nuts) to fill you up and help you eat less. Aim for 25 grams of fiber each day after the age of 40. Other ways to increase your metabolism include:
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.
Vitamins are micronutrients, or substances that the body uses in small amounts, as compared to macronutrients, which are the proteins, fats, and carbohydrates that make up all food. Vitamins are present in food, but adequate quantities of vitamins may be reduced when food is overcooked, processed, or improperly stored. For instance, processing whole wheat grain into white flour reduces the contents of vitamins B and E, fiber, and minerals, including zinc and iron. The body requires vitamins to support its basic biochemical functions, and deficiencies over time can lead to illness and disease.
One exception, he says, is seniors, who may need additional B-12 because as we get older, we absorb less of it. Most of us should skip the supplements and get our Bs from grains, dark green vegetables, orange juice, and enriched foods. People with certain medical conditions or who take drugs that interfere with vitamin absorption may also require supplementation.
Those who want to use natural healing methods, such as the use of food and supplements of essential nutrients to prevent or reverse illness, should consult therapists who are qualified to give advice on how natural therapies can help. I recommend that anyone interested in supplements read the references for this article as well as the archives of the Journal of Orthomolecular Medicine http://orthomolecular.org/library/jom/ and the Orthomolecular Medicine News Service http://orthomolecular.org/resources/omns/index.shtml . Both are free access online.
After basic nutritional requirements are supported, supplements may be used to target specific needs and health conditions. For instance, athletes, men, women, children, the elderly, and vegetarians have differing needs for nutrients, and an informed use of supplements would take these differences into account. People suffering from health conditions and diseases may use specific supplements to target their condition and to support the body's healing capacity by providing optimal amounts of nutrients.
I realize that none of the above foods have 100% DV of calcium, and while we all should be getting a variety of these foods through the week to help increase the amount of calcium from whole foods, you can also boost it with a supplement- especially if you fall into any of the above categories. I’ve really been liking the New Chapter’s Every Woman’s One Daily Multivitamin which has calcium and is rich in vitamin D3. Read more on that in the next question!
Calcium: For adult women aged 19-50, the USDA recommended daily allowance is 1,000 mg/day. For women over 50, the recommended daily allowance is 1,200 mg/day. Good sources of calcium include dairy products, leafy green vegetables, certain fish, grains, tofu, cabbage, and summer squash. Your body cannot take in more than 500 mg at any one time and there’s no benefit to exceeding the recommended daily amount.
There are thousands of dietary supplements on the market, including 40+ essential nutrients alone and in various combinations, i.e. vitamins, minerals, trace elements and fatty acids. However, a number of other nutrients are "conditionally essential", meaning that the body normally can make these molecules, but some people do not make optimal amounts. Examples are L-carnitine, alpha-lipoic acid, the methyl donor betaine,  chondroitin sulfate, coenzyme Q10, choline, amino acids such as tyrosine or arginine, and "essential" sugars normally formed in the body. 
Before and during pregnancy. You need more of certain nutrients than usual to support your health and your baby’s development. These nutrients include protein, calcium, iron, and folic acid. Many doctors recommend prenatal vitamins or a folic acid supplement during this time. Many health insurance plans also cover folic acid supplements prescribed by your doctor during pregnancy. You also need to avoid some foods, such as certain kinds of fish. Learn more about healthy eating during pregnancy in our Pregnancy section.
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. 
Minerals are micronutrients and are essential for the proper functioning of the body. Cells in the body require minerals as part of their basic make-up and chemical balance, and minerals are present in all foods. Minerals can either be bulk minerals, used by the body in larger quantities, or trace minerals, used by the body in minute or trace amounts. Bulk minerals include sodium, potassium, calcium, magnesium, and phosphorus. Trace minerals include iron, zinc, selenium, iodine, chromium, copper, manganese, and others. Some studies have shown that the amount of minerals, particularly trace minerals, may be decreasing in foods due to mineral depletion of the soil caused by unsustainable farming practices and soil erosion. Supplemental minerals are available in chelated form, in which they are bonded to proteins in order to improve their absorption by the body.
Men who choose to drink and can do so responsibly may benefit from one to two drinks a day, counting 5 ounces of wine, 12 ounces of beer, or 1.5 ounces of spirits as one drink. But women face an extra risk: Even low doses of alcohol can raise their risk of breast cancer. So women who choose to drink might be wise to limit themselves to half as much as men.
Nutritional supplements are exactly that, supplements to a healthy, nutritious diet. One should not take nutritional supplements in the hope that they will make up for a poor diet and lack of exercise, they will not! There are some nutritional supplements including some vitamins and minerals, as well as other nutrients/cofactors that one can use in conjunction with a healthy diet to promote optimal health. For example, to consume the amount of vitamin E that has been shown to protect the body against free radical damage, one would have to consume a very significant amount of fat calories as vitamin E is found in foods that are high in fat such as vegetable oils, nuts and seeds. it makes sense to take a supplement of vitamin E rather than consuming lots of fat. The same goes for vitamin D. It's very difficult to get vitamin D in your diet as it isn't found in many foods and studies show that most people do not get enough vitamin D.
Cholesterol is a waxy, fat-like substance made by your body. It also is found in foods made from animals, like meat and dairy. Fruits and vegetables do not contain cholesterol. There are two types of cholesterol: HDL, or "good" cholesterol, and LDL, or "bad" cholesterol. Higher levels of total cholesterol and LDL or "bad" cholesterol raise your risk for heart disease. Almost half of American women have high or borderline high cholesterol.
Ditching the habit and instead focus on good-for-you foods, says Frank Lipman, MD, integrative and functional medicine physician, founder of Eleven Eleven Wellness Center and author of The New Health Rules. Instead of how many calories, ask yourself where the food came from and if it's nutritious. "Healthy, nutrient-rich foods will keep hunger at bay, help maintain stable blood sugar levels, minimize cravings, and help your brain signal your belly when you're full," he says. In other words, you don't have to go through all the trouble of counting.
Don't take dramatic steps alone. You need to work closely with an experienced health care professional to lose weight, particularly if you have other medical problems, plan to lose more than 15 to 20 pounds or take medication on a regular basis. An initial checkup can identify conditions that might be affected by dieting and weight loss. Make sure you find out how much experience your health care professional has dealing with nutrition. It's not always well covered in medical schools. You may want to talk to a registered dietitian before embarking on a diet.
Nutritional supplements may be designed to provide specialized support for athletes. Some of these consist of high-protein products, such as amino acid supplements, while other products contain nutrients that support metabolism, energy, and athletic performance and recovery. People engaging in intense athletic activity may have increased needs for water-soluble vitamins, antioxidants, and certain minerals, including chromium. Sports drinks contain blends of electrolytes (salts) that the body loses during exertion and sweating, as well as vitamins, minerals, and performance-supporting herbs.