Dr. Jason Theodosakis and Dr. David T. Feinberg examine these questions in their book Don't Let Your HMO Kill You, and offer us a bit of clarity on the subject. First, the basics. Theodosakis and Feinberg agree that, though they agree that caution is key, there are a few supplements that you should take for optimum health. Supplements allow you to overcome the deficiencies in your diet that arise from eating processed foods or not getting enough fruits and vegetables. They also make up for the varying levels of nutrients in foods. (Did you know that two carrots grown at either end of the same field can have different nutrient contents?)

Supplements are also important in protecting us against toxins. Those of us who are deficient in minerals will find pesticides more toxic. For example, someone who has a calcium or iron deficiency will be harmed by lead poisoning more than someone who doesn't.

For older people, who sometimes have a diminished ability to digest and absorb nutrients, supplements are crucial, since the nutrients in supplements can often be absorbed more easily than those in food. The most common example of this is vitamin B12. Our ability to absorb this vitamin decreases with age, to the point where some of us must have vitamin B12 administered by injection.

The final reason to take supplements is that it takes high doses of nutrients to prevent or treat disease, far higher than you can get from food alone. The best example of this is the use of vitamin E in the prevention of heart disease, arthritis and Alzheimer's. The required dose for these purposes is usually between 100 and 800 IU per day. To get that much vitamin E (found in wheat germ oil, nuts, seeds, vegetable oils, whole grains, egg yolks and leafy green vegetables) from food would require you to eat thousands of calories per day.

So what should you take? Think of it the way you would medication. What you should take depends on your own personal circumstances. Your dietary supplement intake should be designed carefully to fit your situation. And that means that you should consult with your doctor before taking anything.

But if you're generally healthy, without any major medical conditions, there are a few blanket recommendations we can make. Drs. Feinberg and Theodosakis provide the following guidelines to follow:

• Do not take supplements containing iron without a blood test to check your current iron level. One in 200 of us has a genetic ability to absorb more iron from food than the general population. These people tend to have excess iron in their bodies, which can cause heart disease, diabetes and liver problems.
• Take a multivitamin, since many substances, such as beta-carotene and vitamin E, can be harmful or less effective when taken alone. According to Drs. Feinberg and Theodosakis, the ideal multivitamin contains no more than 5,000 IU of vitamin A, preferably in the form of mixed carotenoids; B-complex: 1.5-3.0 mg B1, 1.7-3.4 mg B2, 20-40 mg B3, 2-4 mg B6, 400 mcg folate and 100-250 mcg B12; 60-180 mg vitamin C; and 100-400 IU vitamin E.
• Take calcium, but not too much. In general, most adult men and women need between 1,200 and 1,500 mg of calcium per day, respectively. Examine your current diet and determine how much calcium you're getting from food. Most of us get approximately 300 mg of calcium from non-dairy foods every day and 300 mg of calcium from every serving of dairy food we consume. Add up those milligrams, subtract the total from either 1,200 or 1,500, depending on your gender, and you have your calcium need. Take that amount of calcium in a supplement.
• If you're taking calcium supplements, take magnesium too. Divide your calcium dose by three, and that's the amount of magnesium you should take.
• Get your minerals with a low-dose multimineral product that includes boron, chromium, copper, manganese, molybdenum, selenium, vanadium and zinc.
• Consider additional antioxidants such as extra vitamin C, mixed vitamin E, selenium, pycnogenol, grape seed extract, alpha lipoic acid, glutathione, green tea extract and N-acetylcysteine.
• Consider adding additional essential oils, such as Omega-3 fatty acids or flax oil.

Remember that the above recommendations are for people without any major medical problems, and be sure that you consult a nutrition-savvy doctor before making any changes to these recommendations. You can find more information on Drs. Feinberg and Theodosakis' recommendations at www.drtheo.com.