Creating an industry estimated to have a 2015 value of $37 billion,[4] there are more than 50,000 dietary supplement products marketed just in the United States,[5] where about 50% of the American adult population consumes dietary supplements. Multivitamins are the most commonly used product.[6] For those who fail to consume a balanced diet, the United States National Institutes of Health states that certain supplements "may have value."[7]
In the United States, the Dietary Supplement Health and Education Act of 1994 provides this description: "The Dietary Supplement Health and Education Act of 1994 (DSHEA) defines the term “dietary supplement” to mean a product (other than tobacco) intended to supplement the diet that bears or contains one or more of the following dietary ingredients: a vitamin, a mineral, an herb or other botanical, an amino acid, a dietary substance for use by man to supplement the diet by increasing the total dietary intake, or a concentrate, metabolite, constituent, extract, or combination of any of the aforementioned ingredients. Furthermore, a dietary supplement must be labeled as a dietary supplement and be intended for ingestion and must not be represented for use as conventional food or as a sole item of a meal or of the diet. In addition, a dietary supplement cannot be approved or authorized for investigation as a new drug, antibiotic, or biologic, unless it was marketed as a food or a dietary supplement before such approval or authorization. Under DSHEA, dietary supplements are deemed to be food, except for purposes of the drug definition."[9]
Iodine is needed for normal mental development of the baby, but it can be difficult to get enough from food. Ways of increasing iodine intake include using iodised salt, eating fish and seafood weekly (see your health professional for advice about safe types and amounts of fish), or using a multivitamin supplement that contains iodine and is safe for pregnancy.

A new twist on an old favorite ― if your favorite recipe calls for frying fish or breaded chicken, try healthier variations using baking or grilling. Maybe even try a recipe that uses dry beans in place of higher-fat meats. Ask around or search the internet and magazines for recipes with fewer calories ― you might be surprised to find you have a new favorite dish!
Use whole grain flour in baking recipes. For some guilt-free indulgence, use whole grain flour in your baking recipes. Whole grain flour includes the bran and the germ which make it more nutritious than its refined counterpart. Start off by subbing half of the flour in the recipe with spelt flour (or any other whole grain flour of your choice) and see how it works. Here are some handy tips for baking with whole grain flours.
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. 

A vitamin is an organic compound required by an organism as a vital nutrient in limited amounts.[12] An organic chemical compound (or related set of compounds) is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. The term is conditional both on the circumstances and on the particular organism. For example, ascorbic acid (vitamin C) is a vitamin for anthropoid primates, humans, guinea pigs and bats, but not for other mammals. Vitamin D is not an essential nutrient for people who get sufficient exposure to ultraviolet light, either from the sun or an artificial source, as then they synthesize vitamin D in skin.[13] Humans require thirteen vitamins in their diet, most of which are actually groups of related molecules, "vitamers", (e.g. vitamin E includes tocopherols and tocotrienols, vitamin K includes vitamin K1 and K2). The list: vitamins A, C, D, E, K, Thiamine (B1), Riboflavin (B2), Niacin (B3), Pantothenic Acid (B5), Vitamin B6, Biotin (B7), Folate (B9) and Vitamin B12. Vitamin intake below recommended amounts can result in signs and symptoms associated with vitamin deficiency. There is little evidence of benefit when consumed as a dietary supplement by those who are healthy and consuming a nutritionally adequate diet.[14]
Thus, higher levels of vitamins and minerals may delay mitochondrial aging, speed up the repair of large molecules such as DNA and collagen, and generally improve other cellular functions. This is an important rationale for taking higher doses of vitamins and minerals than recommended reference intakes. Dietary supplements can slow the aging process, in part by reducing the harmful effects of free radicals, known to be involved in many diseases such as cardiovascular disease and cancer. [36] Naturally-occurring hormones and/or supplements of cofactors needed for optimal hormone production in the body can have a significant life-prolonging effect if the body produces less than optimal amounts. [37] This is especially relevant for those with a genetic predisposition for disease.
Carbohydrates should provide 45%–65% of your daily calories. Most of those calories should come from the complex carbohydrates in high-fiber and unrefined foods, such as bran cereal and other whole-grain products, brown rice, beans and other legumes, and many fruits and vegetables. These carbohydrates are digested and absorbed slowly, so they raise the blood sugar gradually and don't trigger a large release of insulin. People who eat lots of these foods have higher HDL ("good") cholesterol levels and a lower risk of obesity, diabetes, and heart disease. A good amount of soluble fiber in the diet lowers LDL ("bad") cholesterol, and high-fiber diets reduce the risk of intestinal disorders ranging from constipation and diverticulosis to hemorrhoids. Some studies have shown that fiber may help reduce the risk of colon cancer. Men need more fiber than women: 38 vs. 25 grams a day before the age of 50 and 30 vs. 21 grams a day thereafter.