Vitamins and minerals, also known as micronutrients, are vital to good health. But how much do you really need? And is it best to get them from food or supplements? To help you decide, here's a rundown of some essential nutrients.

Vitamins C and E. In recent years there has been a hullabaloo over antioxidants, including vitamins C and E. These vitamins, along with other antioxidant nutrients such as beta-carotene, have been associated with protection against some chronic conditions, including heart disease, cancer and cataracts. As yet, however, there is no scientific proof that antioxidants prevent these diseases.

The recommended daily intake of vitamin C (also called ascorbic acid) is 60 milligrams, although research is ongoing to determine whether higher doses protect against disease. Vitamin C in high concentrations is found in several vegetables and fruits, including green and red peppers, collard greens, broccoli, spinach, tomatoes, potatoes, strawberries and citrus fruits. So, it's relatively easy to get from food, especially if you eat the recommended five servings of fruits and vegetables each day.

Vitamin E, however, is more difficult to get in the diet, since it's found mainly in vegetable oils, nuts, seeds and wheat germ -- not exactly staples of the American diet. The recommended dietary allowance for vitamin E is 30 IU (international units) per day. But research has shown that levels of 100 to 400 IU per day, which are nearly impossible to get from the typical diet, may protect against heart disease. The best bet is to see your doctor to determine your risk and whether a vitamin E supplement is right for you.

Folate. Adequate intake of folate, a B vitamin, is important in preventing neural tube birth defects. It may also offer protection against heart disease by lowering blood levels of a substance called homocysteine. The recommended daily intake is 400 micrograms. Folate is found in fruits and vegetables (especially leafy greens), legumes and orange juice. Grain-based foods, such as wheat flour, breads and cereals are fortified with folic acid, which is the synthetic form of folate. Public-health experts recommend all women capable of becoming pregnant take a supplement containing 400 micrograms of folic acid. For others, eat a variety of foods rich in folate and fortified with folic acid, and supplement if your diet is falling short.

Calcium. The mineral calcium is vital to bone health and can help protect against osteoporosis and fractures. The recommended daily intake for adults is 1,000 milligrams for people aged 19 to 50 and 1,200 milligrams for people older than 50. The best food sources are low-fat milk, yogurt and cheese, and calcium-fortified orange juice. Eat at least three servings a day of these foods to reach the recommended dose, otherwise take a supplement to make up for what you're missing.

Vitamin D. Vitamin D is also crucial for bone health since it helps the body absorb calcium. The recommended daily intake is 200 IU for people younger than 50; 400 IU for people ages 51 to 70; and 600 IU for people older than 70. Few foods contain significant amounts of vitamin D and the ones that do, such as liver, butter, cream and egg yolks, are generally not eaten in large amounts. A good source is milk, since it's fortified with 100 IU of vitamin D per cup. Fortified breakfast cereals and fatty fish are also good choices. Your body can synthesize vitamin D from sunlight but not if you use sunblock and not in the winter in northern climates. So, unless you eat enough vitamin D-rich foods (and many people don't ), take a supplement to reach the recommended level for your age.

Multivitamin/mineral supplements. As long as you realize a "multi" isn't a magic bullet for health and won't correct for a poor diet, it's fine to take one -- and it can help make up for days when your diet isn't exactly perfect. Skip the high potency versions and stick with a basic multi that offers no more than 100 percent of the daily value for each nutrient.

Important caveats to remember when considering supplements:

Supplements don't contain some of the other good stuff supplied by a balanced diet, such as fiber and phytochemicals, and supplements won't correct for a diet high in saturated fat and sodium.

Some is good, but more isn't better. Too much of certain nutrients, including vitamins A and D, can be toxic, so don't overload.

Fancy, expensive supplements aren't necessarily a better buy. Check the label and don't be lured by "special" ingredients or outlandish claims. A generic or store brand is usually as good as a name brand.

Be sure to tell your doctor of any vitamin, mineral or other dietary supplements you are taking, especially if you are taking any medications.