Conventional wisdom has long held that as long as people who are healthy eat well enough to avoid specific nutritional deficiencies, they don’t need to supplement their diet. The only thing they have to do is consume a diet that meets the RDAs –– Recommended Dietary Allowances — and other guidelines for vitamin and mineral intakes developed by health agencies of the federal government.
But even if one accepts the government’s standards for vitamin and mineral intakes as adequate for good health, the evidence is overwhelming that most people don’t come close to meeting those nutritional requirements. Surveys show that only 9% of Americans eat five daily servings of fresh fruits and vegetables — the amount recommended for obtaining the minimum level of nutrients believed necessary to prevent illness.
Average calcium consumption in the United States and Canada is estimated to be about 60% of the current suggested level of 1,000 mg for younger adults — and far below the 1,200 mg recommended for men and women ages 50 to 70.
According to a review of national data by experts at the University of California, Berkeley, people often make food choices that are nutritionally poor: For example, they are more likely to select french fries than broccoli as a vegetable serving, and will opt for a soft drink rather than a glass of skim milk as a beverage. Not only may these and other foods contribute too much fat and sugar to your diet, but they can also result in less-than-optimal intakes of vitamins, minerals, and disease-fighting phytochemicals. Many American diets, these experts point out, contain half the recommended amounts of magnesium and folic acid. Vitamins A, C, and B6, as well as iron and zinc, are other nutrients that surveys show are at notably low levels in the American diet.
Even with the best nutritional planning, it is difficult to maintain a diet that meets the RDAs for all nutrients. For example, vegetarians, who as a group are healthier than meat eaters (and who tend to avoid junk foods lacking in vitamins and minerals), still may be deficient in some nutrients, such as iron, calcium, and vitamin B12. And most people who want to maintain a healthy low-fat diet will have a problem obtaining the recommended amounts of vitamin E from their food alone, because so many of the food sources for vitamin E are high in fat. Another complication is that a balanced diet may not contain the more specialized substances — fish oils, soy isoflavones, or alpha-lipoic acid — that researchers think may promote health. For generally healthy people who cannot always eat a well-balanced diet every day, a supplement can fill in these nutritional gaps or boost the nutrients they consume from adequate to optimal.
There are various other reasons why people who maintain good eating habits might benefit from a daily supplement. Some experts now believe that exposure to environmental pollutants — from car emissions to industrial chemicals and wastes — can cause damage in myriad ways inside the body at the cellular level, destroying tissues and depleting the body of nutrients. Many supplements, particularly those that act as antioxidants, can help control the cell and tissue damage that follows toxic exposure . Recent evidence also indicates that certain medications, excess alcohol, smoking, and persistent stress may interfere with the absorption of certain key nutrients. And even an excellent diet would be unable to make up for such a shortfall.
Source:Your Guide to
Vitamins, Minerals, and Herbs