HEALTH

Should you take multivitamins?

Millions of Americans take multivitamins in the name of better health. In spite of conflicting reports that these supplements combat chronic conditions, top health experts recommend daily multivitamins for nearly everyone. A balanced diet goes a long way to getting the vitamins and minerals you need to feel good and head off health problems. Trouble is, very few people eat right every day.

According to the Dietary Guidelines for Americans, adults are often deficient in:

• Calcium
• Magnesium
• Vitamin A (as carotenoids)
• Vitamin C
• Vitamin E

Vitamin Short-Fall: Who’s at Risk?

Over time, small discrepancies in nutrient intakes can prove problematic for a person, particularly for women in their childbearing years, strict vegetarians, and the elderly.

For instance, shortfalls of iron in the childbearing years may lead to anemia. Too little folic acid very early in pregnancy increases the risk of neural tube defects in developing babies. And vitamin B12 deficits, responsible for irreversible nerve damage and faulty cognition, are more likely in people who avoid animal foods, and in people over the age of 50, whose bodies absorb synthetic vitamin B12 better than the naturally occurring form.

Most nutritionists advocate multivitamins as a way to shore up diets low in nutrients. But multivitamins are dietary supplements, not substitutes for healthy eating. That’s because multivitamins lack a number of beneficial compounds for wellness, including phytonutrients, and fiber, found in plant foods. Multivitamins also typically fall short of the recommend daily amount of calcium and other important vitamins and minerals, too. 

Think of multivitamins as an insurance policy, but don’t fool yourself into thinking dietary supplements measure up to the benefits of maintaining a healthy body weight, eating right, and getting regular physical activity.

Can Multivitamins Curb Chronic Disease?

Don’t bet on multivitamins to keep you free of heart disease , cancer, and other chronic illness. That’s the recommendation of the State-of-the-Science Conference on Multivitamin/Mineral Supplements and Chronic Disease Prevention from the National Institutes of Health.

In the report, the 13-member panel concluded that more research is needed before suggesting multivitamin use to head off disease in healthy, non-pregnant people.

However, the NIH opinion contradicts earlier findings, including a 2002 study from the Harvard School of Medicine published in the Journal of the American Medical Association.  The authors reviewed 35 years worth of research on vitamins and chronic disease, concluding that every adult should take a multivitamin daily as a safe and inexpensive way to optimize health.

Other studies highlight the connection between multivitamin use and well-being, too.

In a group of more than 88,000 women, those who took multivitamins for 15 years or more significantly reduced the risk of colon cancer as compared to those who took multivitamins for less time. The women were part of the Nurses’ Health Study at the Harvard School of Public Health. The research was published in the Annals of Internal Medicine.

Another study found that taking a multivitamin reduced the risk of first-time heart attack in a group of Swedish men and women aged 45 to 70.  

A Word on Who Should Avoid Multivitamins

If you’re being treated for cancer, or have a history of cancer , a multivitamin may not make sense for you. That’s because dietary supplements could help fuel the growth of cancer cells by providing the extra nutrients they need to reproduce. And adding a multivitamin to a steady diet of other, single-nutrient supplements, highly fortified foods, or both, could put you over the top for several vitamins and minerals.

If you have questions about whether a multivitamin is right for you, talk to your doctor or a dietician.

Multivitamins: What to Look For

There may be disagreement about multivitamins’ capacity to curb chronic conditions. But on balance, the evidence for the benefits of multivitamins far outweigh the potential for harm -- considered extremely low for most healthy people -- even if the effects on health are small.

If you’re convinced you need a multivitamin, how do you decide which one is best for you?

Eating a balanced diet rich in whole grains, fruits, vegetables, legumes (beans), and lean protein sources most of the time means you’d do fine with a multivitamin with 100% or less of the daily value (DV) for a wide array of nutrients. Daily values, listed on food and supplement labels, help you determine how a serving of food or supplement fits into the nutrient needs of a 2,000-calorie eating plan.

When picking a multivitamin, pay particular attention to the following to maximize benefit and minimize risk.

• Vitamin A: Choose a supplement with 3,000 International Units or less of vitamin A (about 80% of the DV), with at least 20% of it as beta-carotene, the raw material your body converts to vitamin A on an as-needed basis. Excessive vitamin A as retinol (the preformed variety called acetate  or palmitate on labels) is detrimental to bone and liver health.
• Iron: Men and post-menopausal women should take an iron-free multivitamin/multimineral preparation unless their diet is very low in iron-rich foods, including meat and fortified grains. Iron may accumulate in the body and cause organ damage
• Folic Acid: Women in their childbearing years need 400 micrograms of folic acid (100% of the DV) every day to help prevent neural tube defects in the first month of pregnancy. (Many breakfast cereals supply 400 micrograms of folic acid per serving.)
• Vitamin D: Most multivitamins supply 400 International Units (100% DV) for vitamin D, which is necessary for calcium absorption and may play a role in cancer prevention. Stampfer says while this is a step in the right direction, you may need more vitamin D than a multivitamin and your diet provide, especially if you have dark skin, are overweight, or spend little time outdoors in the summer months.