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. 
You don't have to hunt and skin your supper, but if your chicken has been molded into a nugget, who knows what you're really chewing. And when you choose meat that's been processed into sausage, strips or slices, you're downing sodium and preservatives instead of healthy nutrients, says Adam Drewnowski, Ph.D., director of the nutritional sciences program at the University of Washington at Seattle. Stick to unfussed-with cuts straight from the butcher.
In 1994, the United States Congress passed a law defining nutritional supplements, and requiring them to be labeled as dietary supplements and identified as not intended to be a substitute for certain foods. A nutritional supplement can be defined as a product intended for consumption in tablet, capsule, powder, soft gel, gel cap, or liquid form, and containing vitamin(s), mineral(s), herb(s), other botanicals, amino acids, or any combination thereof.
People use dietary supplements for a wide assortment of reasons. Some seek to compensate for diets, medical conditions, or eating habits that limit the intake of essential vitamins and nutrients. Other people look to them to boost energy or to get a good night's sleep. Postmenopausal women consider using them to counter a sudden drop in estrogen levels.
Nutritional supplements are items that are usually considered non-food items that are used to enhance your nutritional program. Supplements may include, but are not limited to, vitamins, minerals, bars, and energy drinks or sports nutrition products to enhance performance. Supplements should be used alongside a healthy diet, but not replace it. To find a dietitian in your area that can assist you with supplements, go to www.eatright.org.
During adolescence and early adulthood, women need to consume foods rich in calcium to build peak (maximum) bone mass. This will reduce the risk of developing osteoporosis, a progressive condition where there is a loss of bone that leaves those affected more susceptible to fractures. Women also need an adequate iron intake because they lose iron through menstruation. Women also need an adequate intake of calories to support energy and nutritional needs in order for the body to function properly. The amount of calories that an individual needs varies for each person and is based on age, gender and activity level. As a general recommendation, women between 23 and 50 years of age generally need between 1,700 and 2,200 calories per day to maintain their current energy needs and body weight. Older women generally require fewer calories to support and sustain energy needs. Consuming fewer than 1,500 calories per day, even in attempts to lose weight, can put women at nutritional risk and can result in malnutrition and poor health. For more information on how to calculate one’s nutritional needs, go to www.choosemyplate.gov and insert your personal information. The 2005 Dietary Guidelines for Americans is another reference or guide to assist you in learning to eat a balanced and nutritious diet for good health.
A better approach is to make a few small changes at a time. Keeping your goals modest can help you achieve more in the long term without feeling deprived or overwhelmed by a major diet overhaul. Think of planning a healthy diet as a number of small, manageable steps—like adding a salad to your diet once a day. As your small changes become habit, you can continue to add more healthy choices.
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.