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Vitamins & Supplements
Vitamins & Supplements Articles
The list of vitamins and minerals below can give you an understanding of how particular vitamins and minerals work in your body, how much of each nutrient you need every day, and what types of food to eat to ensure that you are getting an adequate supply. The recommendations in this vitamins chart are based largely on guidelines from the Institute of Medicine. Recommended amounts may be expressed in milligrams (mg), micrograms (mcg), or international units (IU), depending on the nutrient. Unless specified, values represent those for adults ages 19 and older.
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31–70: 15 mcg (600 IU) 71+: 20 mcg (800 IU)
Like their names suggest, osteopenia and osteoporosis are related diseases. Both are varying degrees of bone loss, as measured by bone mineral density, a marker for how strong a bone is and the risk that it might break. If you think of bone mineral density as a slope, normal would be at the top and osteoporosis at the bottom. Osteopenia, which affects about half of Americans over age 50, would fall somewhere in between.
The main way to determine your bone density is to have a painless, noninvasive test called dual-energy x-ray absorptiometry (DXA) that measures the mineral content of bone. The measurements, known as T-scores, determine which category — osteopenia, osteoporosis, or normal — a person falls into (see graphic).
Fracture risk increases as bone mineral density declines. A study published in the Journal of the American Medical Association in 2001 reported that a 50-year-old white woman with a T-score of -1 has a 16% chance of fracturing a hip, a 27% chance with a -2 score, and a 33% chance with a -2.5 score.
Vitamin D has been linked to a growing list of health benefits beyond bone strengthening, but many people, particularly seniors, have vitamin D deficiency. Because few foods are rich in the vitamin, taking a supplement is recommended.
Folic acid is essential to the production of new cells, and helps protect against certain kinds of birth defects, but studies have suggested that an excess of folic acid may contribute to the growth of cancer cells.
A friend recently recommended that I take the herb ginkgo biloba to protect against getting dementia. Is it effective, and is it safe?
Recently, news stories reported that studies found that daily calcium and vitamin D supplements may not help older women protect their bones or prevent colon cancer — at least not as much as we thought they would.
Researchers for the Women's Health Initiative (WHI) looked at more than 36,000 healthy women ages 50–79. Half of the women took 1,000 mg of elemental calcium and 400 IU of vitamin D each day. The other half took a sugar pill (placebo). After seven years, the women taking the supplements showed slightly better bone density in their hips. They also had fewer hip fractures, but the results could have occurred by chance: Protection against hip fractures, a key goal of improving bone density, was not proven.
So, should women ditch their TUMS, calcium chews, and vitamin-D–fortified dairy foods?
Bacteria have a reputation for causing disease, so the idea of tossing down a few billion a day for your health might seem — literally and figuratively — hard to swallow. But a growing body of scientific evidence suggests that you can treat and even prevent some illnesses with foods and supplements containing certain kinds of live bacteria. Northern Europeans consume a lot of these beneficial microorganisms, called probiotics (from pro and biota, meaning "for life"), because of their tradition of eating foods fermented with bacteria, such as yogurt. Probiotic-laced beverages are also big business in Japan.
Some digestive disease specialists are recommending probiotic supplements for disorders that frustrate conventional medicine, such as irritable bowel syndrome. Since the mid-1990s, clinical studies suggest that probiotic therapy can help treat several gastrointestinal ills, delay the development of allergies in children, and treat and prevent vaginal and urinary infections in women.
By now, nearly everyone has heard of the health benefits of the omega-3 fats found in fish. The most persuasive studies show that they protect against the serious — and sometimes fatal — episodes of an irregular heart rhythm that can cause sudden death. Other research indicates that a diet rich in omega-3 fats may lower your risk for heart attack and stroke.
Farm-raised salmon is one of the better sources of omega-3s. A 6-ounce serving contains about 3½ grams which is much more than in other popular fish. There's no straight answer to whether farm-raised or wild salmon has more omega-3 fat—it depends on what they eat. Today about half of the salmon sold worldwide comes from fish farms.
Polychlorinated biphenyls (PCBs) are oily, synthetic chemicals that were used in electrical equipment and as additives to paint, plastics, and other products. Unfortunately, they're now found in today's farm-raised salmon. The federal government ordered industry to stop making them in the 1970s, but they still get freshly released into the environment from hazardous waste sites, leaks from old equipment, and incinerators. PCBs also stick to soil and sediment and can travel long distances through the air. They also "bioaccumulate" in fat, so concentrations tend to be higher in animals — like salmon and marine mammals like seals — that are further up the food chain. High doses kill fish, and PCBs have been linked to reproductive and immunological problems in several species of wildlife.