Over 50% of American adults (myself included) take some type of vitamin each day. I have personally taken a multivitamin since I was a child (flashback to those Flintstones chewables) .
The Vitamin Verdict
Research has concluded that multivitamins (and vitamins in general) don’t reduce the risk for disease. In fact, the fat-soluble vitamins (A,D,E,K) can actually be lethal at high enough doses.
The exception is supplemental folic acid for women of child-bearing potential. Folic acid prevents neural tube defects in babies when women take it before and during early pregnancy. The Centers for Disease Control and Prevention recommends that all women of reproductive age get 400 micrograms of folic acid daily.
Most individuals can get all of the necessary vitamins and minerals through a healthy eating pattern of nutrient-dense foods. Taking a vitamin increases overall nutrient intake and helps some people get the recommended amounts of vitamins and minerals when they can’t or don’t get them from food alone. But taking a vitamin can also raise the chances of getting too much of some nutrients, like iron, vitamin A, zinc, niacin, and folate/folic acid, especially when a person takes more than a basic, once-daily product that provides one hundred percent of the Daily Value (DV) of nutrients.
There’s no standard or regulatory definition for vitamins, or any dietary supplement, as to what nutrients they must contain or at what levels. Manufacturers choose which vitamins, minerals, and other ingredients, as well as their amounts, to include in their products. Simply stated, dietary supplements aren’t required to be standardized in the United States.
Smokers, and possibly former smokers, should avoid products that provide more than 100%DV for vitamin A (either as preformed retinol or beta-carotene or some combination of the two) because two studies have linked high supplemental doses of these nutrients with an increased risk of lung cancer in smokers.
Taking excess amounts of vitamin A (preformed retinol form, not as beta-carotene) during pregnancy has been shown to increase the risk of birth defects.
Except in cases of iron deficiency or inadequacy, or unless a physician recommends otherwise, adult males and postmenopausal women should avoid using iron supplements or vitamins containing more than their Recommended Daily Allowance for iron (8 mg/day). Iron supplements may be recommended for women of childbearing age, pregnant women, preterm infants, older infants, and teenage girls because they are at greater risk of developing deficiency. Yet, iron supplements are a leading cause of poisoning in young children, so parents and guardians should keep iron-containing supplements out of the reach of children.
The Fitness Doctor's Thoughts
Multivitamins cannot take the place of eating a variety of foods that are important to a healthy diet. Some people who don’t get enough vitamins and minerals from food alone, or who have certain medical conditions, might benefit from taking vitamins. However, evidence to support their use for overall health or disease prevention in the general population remains limited.
Conclusion: There is little to no evidence to support the use of vitamins. They are not well regulated. They could possibly do more harm than good. You are literally peeing your money away, unless you are medically deemed deficient. If you consume a nutritionally balanced diet, you have absolutely no reason to take a vitamin. So my advice is to save your money, starting today, I am...