TAKING VITAMIN AND MINERAL supplements may be one of the healthiest habits you can adopt. Mounting research suggests that supplements can help protect you against diseases like heart disease and cancer. "In addition to eating plenty of fruits and vegetables, I think it's smart to take vitamin and mineral supplements," says Jane Higdon, R.N., Ph.D., research associate at the Linus Pauling Institute in Corvallis, Wash. "Supplements are a good insurance policy" for times when your diet falls short, she says.
It's simpler (and cheaper) to take vitamins preventively than to treat disease when you're sick, but shopping for supplements is far from simple. The shelves in the supplement aisle are so crowded that it's hard to know where to begin.
To help you protect your health while saving time and money in the supplement aisle, we asked supplement researchers and nutritionally minded doctors hundreds of questions, like which supplements really prevent common diseases? What dose is most effective? And which forms work best? We sorted through their advice to create this guide to the most important vitamin and mineral supplements everyone should take. Most of the nutrients we describe can be found in a good multivitamin; we tell you how to choose a great multi, and let you know when you need to take other supplements, too.
Vitamin A and Beta Carotene
Why You Need Them: You need vitamin A (also known as retinol) to protect your eyesight as you age and to help your skin heal. Vitamin A comes from animal foods like liver, eggs, and milk, but your body also makes this vitamin from beta carotene, a plant chemical that gives orange produce its color. In addition to providing vitamin A, beta carotene, an antioxidant, neutralizes damaging free radicals. Studies show that people who eat five to nine daily servings of beta-carotene-rich produce have a lower risk of cancer.
Which Form Is Best: Choose a multivitamin supplement that supplies some vitamin A as retinol and some as beta carotene. (Check the label under vitamin A; most specify the percentage that's beta carotene. Choose a brand that offers at least 25 percent beta carotene.) Too much retinol may have serious side effects, says Higdon. A new study in the Journal of the American Medical Association found that women who took about 7,000 IU of retinol daily were at greater risk for hip fracture, and more than 10,000 IU daily can trigger miscarriages and birth defects.
And you don't want too much supplemental beta carotene, either, especially if you're a smoker or you're regularly exposed to cigarette smoke, says researcher Xiang-Dong Wang, M.D., Ph.D. A 1996 study found that smokers who took large doses of beta carotene had an increased risk of lung cancer. Based on recent studies he conducted on animals, Wang believes the problem arose because subjects took high doses of beta carotene alone, which appears to trigger pre-cancerous changes in smoke-exposed cells. Beta carotene probably needs to be combined with other plant chemicals found in fruits and vegetables to produce a beneficial effect, even if you're not a smoker, Wang says. For that reason, some practitioners recommend that everyone take "mixed carotene" supplements. But Wang recommends that you stick to the modest amount of beta carotene in a multivitamin and eat five to nine servings of carotene-rich foods like carrots, citrus fruits, and tomatoes every day.
Effective Dosage: Get vitamin A and beta carotene from a multivitamin that provides up to 5,000 IU of vitamin A. (Choose a brand that offers at least 25 percent as beta carotene.) Increase your protection against disease by eating five to nine servings of produce daily.
Why You Need It: Vitamin [B.sub.6] may reduce heart disease risk. Many studies over the last decade have confirmed that it works together with [B.sub.12] and folic acid to reduce blood levels of homocysteine, an amino acid that increases your chances of heart disease and cognitive decline as you age. Some practitioners recommend high doses of [B.sub.6] to help you cope with stress, carpal tunnel syndrome, and PMS, but those uses have been less studied. "Some people swear by those higher doses, but I just haven't found a lot of placebo-controlled research that supports them," Higdon says. And it's important to avoid very high doses of B6 (more than about 200 mg daily) because they can lead to numbness and nerve pain.
Which Form Is Best: Pyridoxine hydrochloride, a common, inexpensive form, appears to work fine, Higdon says.
Effective Dosage: Most of the experts we consulted recommend that you stick to about 2 mg of [B.sub.6] a day (the amount in many multivitamins). Doses of 50 to 100 mg a day (found in B-complex formulas) aren't harmful, Higdon says, but it's not clear that they're beneficial. Don't take more than 200 mg of [B.sub.6] daily.
Why You Need It: Like vitamin B6, vitamin [B.sub.12] helps reduce homocysteine, a substance in blood that increases heart disease risk. It may also influence your mood; studies show that depressed people are often deficient in the vitamin, and scientists believe [B.sub.12] helps your body produce SAMe, a compound that boosts levels of mood-lifting neurotransmitters.
It's widely available in animal foods including dairy, eggs, fish, and poultry. But an estimated 10 to 40 percent of older adults have atrophic gastritis, a stomach condition that limits their ability to absorb [B.sub.12], says nutritional epidemiologist Katherine Tucker, Ph.D. Vegans (who don't eat any animal products) and people who take antacids or stomach acid drugs may also be deficient, she adds.
Which Form Is Best: Studies show that cyanocobalamin, the typical [B.sub.12] in supplements, works well, Tucker says.
Effective Dosage: Most people should take 6 mcg a day, the amount in many multivitamins. But because an inability to absorb [B.sub.12] is so common, some experts recommend that people over 65 (and others who may be deficient) take 100 to 400 mcg daily. Tucker says that although most people probably don't need that much, large doses aren't harmful.
Why You Need It: This antioxidant protects cells against the free radical damage that can lead to cancer and heart disease. Your body needs it to build collagen, an important component of bone, and it also appears to reduce the severity and duration of colds. It's found in many fruits and vegetables, including bell peppers, strawberries, and citrus fruits.
You may have seen headlines about a study that found that vitamin C can damage DNA, but the experts we consulted say this was only a test tube study; there's no evidence that vitamin C behaves the same way in your body.
Which Form Is Best: The cheapest form, ascorbic acid, is probably best, says researcher Jane Higdon, R.N., Ph.D.
Effective Dosage: The experts didn't agree. Several recommended 1,000 to 2,000 mg per day, taken in divided doses. Others, like Higdon, believe you don't need more than 200 mg daily. Recent studies found that the blood and tissues of young, healthy adults became saturated at that dose. However, Higdon acknowledges that the elderly or people with diseases like cancer may benefit from doses higher than 200 mg. Those people haven't been studied yet, so "we just don't know," she says. Start with 200 mg if you're in good health, and talk to a nutritionally minded doctor if you think you could benefit from more. Higdon adds that doses up to 2,000 mg appear to be safe, but higher doses can cause diarrhea. If that happens, reduce your dose.
Why You Need It: This nutrient helps you absorb calcium to keep your bones strong. Many foods, like milk and soymilk, are fortified with vitamin D, and your skin makes all the vitamin D you need if you spend 15 minutes in strong sunlight three times a week. But you may need a supplement if you're over 65 (when researchers believe your skin loses the ability to convert vitamin D) or from October through March if you live in northern regions above about 42 degrees latitude (Boston and Chicago are both around 42 degrees latitude).
Which Form Is Best: Two forms are available: cholecalciferol and ergocalciferol, and there is virtually no difference between the two, explains vitamin D researcher Hector DeLuca, Ph.D.
Effective Dosage: Most people should take 400 IU, the amount in many multivitamin supplements, DeLuca says.
Why You Need It: It's important to take vitamin E in supplement form because it's nearly impossible to get all you need from food. And researchers agree that it's good insurance against disease. As an antioxidant, it protects cells against free radical damage, thereby helping to prevent cancer and, most impressively, heart disease. In a study of 2,000 people with advanced heart disease published in the Lancet, those who took 400 to 800 IU of vitamin E daily lowered their risk of non-fatal heart attacks by 77 percent.
Which Form Is Best: Some of the experts we consulted recommend the natural form (shown on labels as d-alpha tocopherol); it's more potent than the synthetic form. Although some recommend that you get vitamin E from a "mixed tocopherol" supplement (which includes related compounds like beta, delta, and gamma tocopherol), researcher Jane Higdon, R.N., Ph.D., says studies suggest that your body prefers the alpha tocopherol form and rapidly excretes other forms.
Effective Dosage: Most multivitamins contain very small amounts of vitamin E. On top of your multivitamin, take an additional 400 IU supplement with a meal that contains a little fat. Talk to your doctor if you take blood thinners; vitamin E can have a blood-thinning effect.
Why You Need It: This B vitamin is important for women who may become pregnant; it helps prevent neural tube defects in developing babies. It also protects against cancers, including cervical cancer, and works with [B.sub.6] and [B.sub.12] to lower homocysteine, a substance in blood that increases your risk of heart disease. Alcoholic drinks and birth control pills can deplete your body's supply of folic acid.
Which Form Is Best: The same form is used in most supplements.
Effective Dosage: The experts we consulted recommend 400 mcg daily, the amount in most multivitamins. If your doctor has confirmed that you have high homocysteine levels, you may want to take an additional 400 mcg, Higdon says. Make sure your multivitamin also contains [B.sub.12]; taking folic acid long term may mask a vitamin [B.sub.12] deficiency.
Why You Need It: This mineral is famous as a bone protector, but it plays other important roles, too, helping your nerve cells communicate, your muscles contract, and your blood clot. It also appears to lower blood pressure and help prevent colon cancer and premenstrual syndrome.
Which Form Is Best: Supplements made of calcium carbonate are easy to find and inexpensive, but they should always be taken with food for best absorption. Another common form, calcium citrate, can be taken anytime. Physician Elson M. Haas, M.D., recommends that you take calcium at bedtime with magnesium because they work together to relax your muscles and help you fall asleep.
Effective Dosage: Take 500 to 1,000 mg a day. If you take calcium carbonate, take it with food; you can take calcium citrate any time. If you eat leafy greens, drink fortified orange juice or soymilk, and consume dairy products like yogurt daily, you probably need just one 500 mg calcium supplement a day. Never take more than 500 mg of calcium at once; you can only absorb a certain amount at a time.
New studies suggest that men who get 2,000 mg or more of calcium daily have an increased risk of advanced prostate cancer. Based on those findings, researchers say men should probably limit their intake from food and supplements to 1,000 to 1,200 mg daily.
Why You Need It: This mineral appears to help the hormone insulin work more efficiently, making it an especially important nutrient for people who have type 2 diabetes or are at risk for it. (Insulin usually helps lower blood sugar levels, but if you have type z diabetes, your insulin is less effective.) In fact, some cases of type z diabetes are triggered by a chromium deficiency, says chromium researcher Richard A. Anderson, Ph.D.
Chromium's effect on insulin may also help you lose weight. Studies show that it can help you hold on to muscle while shedding fat. But Anderson warns that you won't drop extra weight overnight. "Don't expect to see results for 10 to 12 weeks," he says.
Which Form Is Best: Chromium picolinate is the form most often used in studies.
Effective Dosage: Most people need 50 to 200 mcg daily. If you have diabetes or a pre-diabetic condition, Anderson recommends 200 mcg two or three times a day. For best absorption, he advises that you take chromium in a separate supplement (ignore the amount in your multivitamin), and take it at a different time than your multi. If you take diabetes medication, talk to your doctor; chromium may reduce your need for these medications.
Why You Need It: Copper helps transport oxygen through your body, maintains hair color, and is used to make hormones. If you're supplementing with zinc, it's especially important to take copper; zinc interferes with your body's ability to absorb copper. This mineral is found in oysters and Brazil nuts.
Which Form Is Best: Research suggests that the form doesn't matter.
Effective Dosage: You don't need much. Our experts recommend 1 to 2 mg daily, the amount in most multivitamins.
Why You Need It: You need this mineral to make hemoglobin, the part of red blood cells that carries oxygen around your body, and a lack of iron can cause fatigue. But many foods are fortified with iron, and too much increases your risk of heart disease and certain cancers. Iron deficiency typically affects only premenopausal women (who shed the red blood cells that line the uterus), endurance athletes (who sometimes experience slight gastrointestinal bleeding), and vegetarians (who eat less iron than nonvegetarians).
Which Form Is Best: Several of our experts advised against ferrous sulfate. It's inexpensive but more likely to trigger side effects like constipation and nausea. It can also destroy vitamin E in your body, says nutritional consultant Phyllis Balch. Opt for ferrous gluconate or ferrous fumarate instead.
Effective Dosage: Most multivitamins contain 18 mg. This amount is recommended for women who menstruate, but it's too much for most men and postmenopausal women, who should take an iron-free multivitamin. If you don't menstruate and think you're iron deficient because you feel fatigued, ask your health care practitioner to test your blood before you supplement.
Why You Need It: Among its many functions, the mineral magnesium maintains your bones and helps your muscles relax. Food sources of magnesium include beans and artichokes.
Which Form Is Best: Physician Elson M. Haas, M.D., usually recommends magnesium citrate, gluconate, or aspartate because they're better absorbed, but he says that magnesium oxide (a common and inexpensive form) is also absorbed decently. Haas recommends taking it before bed with your calcium supplement; these two minerals work together to help your body relax for sleep.
Effective Dosage: Our experts recommend that you take 300 to 500 mg of magnesium daily, which is more than most multivitamins contain. Magnesium supplements may trigger diarrhea. Reduce your dose if this occurs.
Why You Need It: An electrolyte (a substance that maintains your body's fluid levels), this mineral helps regulate blood pressure and heart function. Research shows that increasing your potassium intake can lower your blood pressure.
Which Form Is Best: Get your potassium by eating lots of produce. Good sources include bananas, orange juice, dried dates, and apricots. You need about 3,500 mg daily, but over-the-counter supplements contain no more than 99 mg. The small amount in your multivitamin is fine, but many practitioners advise against taking more than 99 mg daily in supplement form because it can irritate your stomach.
Effective Dosage: Take a multivitamin and eat at least five servings of fruits and vegetables daily.
Why You Need It: The mineral selenium could be your most potent ally against cancer. A study at the University of Arizona in Tucson in 1996 found that people who took 200 mcg of selenium a day for four and a half years reduced their risk of cancer by 32 percent and their risk of death from cancer by 50 percent. Selenium, an antioxidant, appears to regenerate vitamins E and C so that they can continue to fight free radicals. Brazil nuts are an especially good food source.
Which Form Is Best: Haas recommends that you take selenomethionine, a natural form that is less easily convened in your body to potentially toxic elemental selenium.
Effective Dosage: Take 200 mcg a day with food. Be aware that doses of more than 400 mcg daily can be toxic.
Why You Need It: Among its many functions, the mineral zinc strengthens your immune system and supports reproduction: It helps sperm develop and is needed for ovulation and fertilization. Research also suggests that taking lozenges made of zinc gluconate can help shorten the length of a cold. Pumpkinseeds and oysters are good food sources.
Which Form Is Best: Most forms of zinc work equally well, Haas says. But if you're trying to prevent a cold, use zinc lozenges or a zinc spray made of zinc gluconate.
Effective Dosage: Take 15 mg of zinc daily (the amount in most multivitamins). Because zinc can block copper absorption, make sure that your supplement also contains 1 to 2 mg of copper. To fight colds, use a zinc nasal spray four times a day or suck on zinc lozenges that contain 15 to 25 mg of zinc gluconate every two to four hours as soon as you notice symptoms. Stop when symptoms subside. Consuming zinc on an empty stomach can cause nausea, so take zinc supplements with food.
Why You Need It: A powerful antioxidant that neutralizes damaging free radicals, this vitamin like substance can have an energy-boosting effect and may protect your heart and gums from disease. Researchers found that people with heart disease and gingivitis lack coenzyme [Q.sub.10] (Co[Q.sub.10]) in their bodies, and taking cholesterol-lowering drugs long-term may further deplete your Co[Q.sub.10] levels. Several studies have confirmed that this antioxidant can treat cardiomyopathy, heart failure, and gum disease.
Which Form Is Best: Some research suggests that oil-based capsules and sublingual forms of Co[Q.sub.10] are particularly well-absorbed, says holistic physician Michael Janson, M.D. It's an expensive supplement, so be sure to shop around for the best price.
Effective Dosage: The experts we consulted recommend 50 to 200 mg daily (taken with meals that contain a little fat) to increase energy and treat gum disease. If you have heart problems, take divided doses of up to 400 mg daily. Consult your doctor before taking Co[Q.sub.10] with medication for heart problems; you may need to adjust your medication. Multivitamins rarely contain Co[Q.sub.10].
Omega-3 Fatty Acids
Why You Need Them: Omega-3 fats aren't vitamins or minerals, but they're so important for good health that some experts say no supplement routine is complete without them. New research confirms that these fats (especially two of them, EPA and DHA) play an important role in reducing heart disease. A study published in the Journal of the American Medical Association this year found that women who eat two to four weekly servings of fish (a good source of these fats) had almost one-third fewer heart disease deaths than women who rarely eat fish. Another 2002 study in Circulation found that heart attack survivors who took fish oil supplements had half the level of sudden death as those who didn't take supplements. Fish oil may also treat depression; a 1999 study found that people with manic depression improved while taking fish oil. Scientists also believe fish oil reduces inflammation, making it beneficial for treating diseases like arthritis.
Which Form Is Best: The best way to get EPA and DHA is to eat cold-water fish like wild salmon at least twice a week. Fish oil capsules appear to provide similar benefits. In place of fish or fish oil capsules, vegetarians can add flaxseed oil to their diet, but be aware that flaxseeds contain a different type of omega-3, called LNA, and your body may not be as efficient at making the EPA and DHA it needs from LNA.
Effective Dosage: Eat cold-water fish twice a week or take 1,000 mg of fish oil capsules daily. Fish oil spoils easily, so look for capsules that contain a little vitamin E, which prevents rancidity. These supplements can cause gas or diarrhea; taking them in divided doses may reduce these symptoms. If you're a vegetarian, add 1 to 2 tablespoons of flaxseed oil to salads or cooked vegetables daily.
Should I Buy Time-Release Supplements?
Skip them, our experts say. Many time-release tablets are too hard to digest, says physician Michael Janson, M.D. In fact, they may not break down until they're so far in your intestine that your body can't use the nutrients they contain.
The Bottom Line
Can I Get All I Need from a Multivitamin?
A good multivitamin will provide most of the important vitamins and minerals we feature in this guide, but no multivitamin can provide them all, our experts say. These are the numbers to look for in a multivitamin and multi-mineral supplement.
Your multivitamin should contain (at a minimum):
Vitamin A/Beta Carotene: 5,000 IU (Most labels state the percentage of beta carotene; choose a brand that provides at least 25 percent beta carotene.)
Vitamin [B.sub.6]: 2 mg
Vitamin [B.sub.12]: 6 mcg
Vitamin C: 60 mg
Vitamin D: 400 IU
Vitamin E: 60 IU
Folic Acid: 400 mcg
Calcium: 150 mg
Chromium: 120 mcg
Copper: 1 to 2 mg
Iron: 18 mg if you're a menstruating woman; 0 mg if not
Magnesium: 100 mg
Potassium: 40 to 99 mg
Selenium: 70 mcg
Zinc: 15 mg
Most multivitamins won't give you what you need of the following nutrients, Take additional supplements if necessary to reach these daily doses.
Vitamin [B.sub.12]: Aim for 100 to 400 mcg if you're over 65.
Vitamin C: Aim for 200 mg.
Vitamin E: Aim for 400 IU.
Calcium: Aim for 500 to 1,000 mg.
Chromium: Take 50 to 200 mcg in addition to your multivitamin.
Magnesium: Aim for 300 to 500 mg.
Selenium: Aim for 200 mcg.
Coenzyme [Q.sub.10]: Aim for 50 to 200 mg.
Omega-3 Fatty Acids: Aim for 1,000 mg of fish oil capsules, or 1 to 2 tablespoons of flaxseed oil.
Our Supplement Experts
Richard A. Anderson, Ph.D., is a researcher who specializes in chromium at the Beltsville Human Nutrition Research Center in Beltsville, Md.
Phyllis Balch is a certified nutrition consultant in Cape Coral, Fla., and the author of several books on nutrition and supplements, including Prescription for Herbal Healing (Avery, 2002).
Hector DeLuca, Ph.D., a professor of biochemistry at the University of Wisconsin in Madison, is an expert on vitamin D.
Annette Dickinson, Ph.D., is the vice president of scientific and regulatory affairs at the Council for Responsible Nutrition, a supplement trade association in Washington, D.C.
Elson M. Haas, M.D., is the founder and director of the Preventive Medical Center of Marin in San Rafael, Calif. A member of the Natural Health advisory board, he's the author of several books, including the classic Staying Healthy with Nutrition (Celestial Arts, 1992).
Jane Higdon, R.N., Ph.D., is a research associate at the Linus Pauling Institute (LPI), a nutrient research and education organization at Oregon State University in Corvallis. She researches and writes LPI's Micronutrient Information Center website.
Frank Hu, M.D., Ph.D., is assistant professor of nutrition at the Harvard School of Public Health in Boston.
Michael Janson, M.D., is a complementary physician in Arlington, Mass., and author of Dr. Janson's New Vitamin Revolution (Avery, 2000).
Katherine Tucker, Ph.D., is associate professor of nutritional epidemiology at the Tufts University School of Nutrition in Boston.
Xiang-Dong Wang, M.D., Ph.D., is associate professor of nutrition and medicine at the Human Nutrition Research Center on Aging at Tuffs University in Boston.
Do My Supplements Contain What They Should?
To be sure, you can check www. consumerlab.com, an independent website that tests some supplements and lists the companies that sell products that contain what they promise. You can purchase a single list (of calcium supplements, for example) for $5.25, or pay $15.95 and get access to all the lab's results for a year.
How Do I Know if I'm Digesting My Supplements?
If you're in doubt, nutrition consultant Phyllis Balch suggests this home test for tablet-form supplements (especially calcium): Add the supplement to 1 cup of vinegar and stir every few minutes. It should dissolve in 30 minutes. "If it doesn't, it won't dissolve in your stomach either and you should choose another supplement," Balch says.
Erin O'Donnell is a Natural Health senior editor. While writing this story she added selenium and chromium to her supplement regimen.
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