Vitamins and minerals are powerfully important substances your body needs to function at its peak level. Found in the foods we eat, each one has a different role to play. Vitamin D and calcium, for example, are needed for strong bones, while the B vitamins help you make energy when your body needs it (think lifting weights or running), vitamin A is crucial for night vision, and zinc and vitamin C help you heal and resist infection.
Hands-down, food, not pills, is the best way to get the vitamins and minerals your body needs. In fact, scientists have found that something called food synergy, the interaction that occurs between nutrients in food, has yet to be reproduced by simply popping a pill. Realistically, however, eating a perfectly well-balanced and healthy diet (including at least nine servings of fruits and vegetables a day, as well as whole grains, low-fat dairy, and lean meat, poultry, or fish) on a day-to-day basis is not always possible.
Taking a multivitamin and mineral supplement is a sensible insurance policy to help you fill in the nutrition gaps. But the question remains, which pill to take?
The A, B, C's...and Z's?
Rather than trying to guess how much you're not getting from food, it's easier to look for a pill that has 100 percent of the Daily Value (often written as %DV—this is the Food and Drug's Administration's advice on how much of each vitamin and mineral to shoot for each day) for most vitamins and minerals. Taking this amount in a daily multi generally won't put you at risk of overdoing it, since the risk of dietary deficiencies is far greater than the risk of overdosing on vitamin and mineral supplements.
However—and this is a big however—the DVs have not been updated since the 1970s, and in some cases they are outdated. For those vitamins and minerals, recommendations come from the Institute of Medicine (IOM). Confused? Don't be. Here's what you do and don't need to look for in a one-a-day multi:
Vitamin C: Look for 100 percent of the DV—60 milligrams (mg)—but keep in mind the IOM recommends 90 mg a day for men. Also keep in mind that around 250 to 500 mg will saturate the body's tissues, so any more than that is probably excreted.
Vitamin A: The DV of 5000 International Units (IU) is obsolete. The IOM suggests just 3000 IU a day, as research shows that too much retinol may increase the risk of hip fractures and liver problems. Experts say you should look for no more than 3000 IU of retinol or 15,000 IU of beta-carotene (which the body converts to A) from your multi.
Vitamin B-1 (thiamine): Look for 100 percent of the DV—1.5 mg.
Vitamin B-2 (riboflavin): Look for 100 percent of the DV—1.7 mg.
Vitamin B-3 (niacin): Look for 100 percent of the DV—20 mg.
Vitamin B-6: Look for 100 percent of the DV—2 mg. More than 100 mg can cause neurological damage.
Vitamin B-12: Look for 100 percent of the DV—6 micrograms (mcg)—unless you are over 50. Men over 50 may have a decreased ability to absorb vitamin B12 from food, so experts advise this age group to look for 25 mcg of B12 in their multi.
Vitamin D: Look for 100 percent of the DV—400 IU.
Vitamin E: Look for 100 percent of the DV—30 IU. More may protect against prostate cancer, but too much may raise your risk of dying (not a good thing). Until further research can verify, play it safe with no more than 100 IU.
Iron: While the DV is 18 mg, experts say that men should look for a multi with no more than 9 mg of iron. Iron overload can cause health problems in men, including joint pain, heart palpitations, and impotence (while not as bad as dying—see the vitamin E overdose warning above—also not a good thing).
Folic Acid: Look for 100 percent of the DV—400 mcg.
Calcium: Men need 100 percent of the DV (1000 mg). That said, calcium is bulky and won't fit into a one-pill multi. If you don't eat three to four servings of low-fat dairy or calcium-fortified OJ everyday, take a 300 mg pill for each serving you miss. On the flip side, more than 2000 mg a day may increase your risk of prostate cancer, so don't go overboard.
Zinc: According to the IOM, males need 11 mg, but you can take a multi with 100 percent of the DV (15 mg). Just be sure you don't take much more. More than 40 mg a day can make you lose copper, and even higher amounts (300 mg a day) can weaken your body's defenses.
Copper: According to the IOM men only need 0.9 mg a day, but there is no harm associated with getting 100 percent of the DV (2 mg).
Vitamin K: Most multis have far less than the IOM recommended amount (120 mcg) or even the DV (80 mcg). Look for one with at least 25 mcg. However, vitamin K can interfere with blood-thinning medications, so people taking such medications should consult their doctor before taking a multi with vitamin K.
Magnesium: It's hard to find a multi with 100 percent of the DV (400 mg). This may in fact be a good thing, since more than 350 mg a day from supplements may cause diarrhea. Look for a multi that provides at least 100 mg of magnesium.
Selenium: Many multis have far less than the DV (70 mcg) or the IOM recommendation (55 mcg). Try to find on one with at least 50 mcg, but keep in mind that more than 800 mcg a day can make your nails brittle and your hair fall out (not a good look...).
Chromium: While the IOM recommends just 30 to 35 mcg for men, many multis have closer to 100 percent of the DV (120 mcg), which is safe to take.
Iodine, Manganase, Molybdenum, Biotin, Pantothenic Acid, Chloride, Boron, Phosphorus, Potassium, Nickel, Silicon, Tin, and Vanadium: Ignore these. There is no evidence that men need more than what they get from food, and you would have to eat a very strange diet to ever run low on any of these.
Lutein, Lycopene, and Zeaxanthin: Ignore these. The IOM has not set recommended dietary intakes for these substances. Until further research proves otherwise, assume companies add these "extras" for marketing purposes.
Unfortunately, the government doesn't require dietary supplements to undergo the same testing as medicines, so picking a product that you can trust is tricky business. Your best bet is to choose well-known brands by companies that have a lot on the line, and to also buy from large, trusted retailers. Also look on the bottle for a stamp from USP, NSF or ConsumerLab.com. While the stamp does not guarantee the product is safe and effective, it does show that the manufacturer has submitted the product for testing to show that it contains what is stated on the label.
The Bottom Line
Supplements are intended to enhance, not take the place of, a healthy diet, so even if you take a multi, you still need to eat a balanced diet. See some of the related articles below to get a good start on healthier eating, or browse RealJock.com's Nutrition section.
About H.K. Jones: H. K. Jones is a registered dietitian, freelance writer, and nutrition professional based in Washington, D.C.