Spin the bottle: how to pick a multivitamin

Nutrition Action Healthletter, Jan-Feb, 2003 by Bonnie Liebman

Taking a multivitamin-and-mineral supplement is a sensible and inexpensive insurance policy. But which multi?

Even if you had the time to squint at the back of all the bottles, who can remember how much of which nutrients you need? No wonder vitamin-makers slap claims like "women's exclusive" or "senior formula" on their labels. That's as far as most shoppers are likely to read.

To make your mission nearly impossible, new evidence keeps changing the amounts of vitamins and minerals that experts recommend. Yet the Daily Values (DVs) that are listed on multi labels haven't changed since the mid-1970s.

Here's how to cut through the label claims and outdated numbers to find the multi that's best for you.

You don't need a fancy multi. Some of our Best Bites are inexpensive private-label brands that are sold at stores like Eckerd, Kmart, Kroger, Rite Aid, Safeway, Sav-on, Walgreens, and Wal-Mart. Or you can walk into just about any pharmacy and pick up a bottle of Theragran-M (or one of its clones).

So why do you need our chart (see p. 5)? Because multis haven't adjusted their ingredients to keep up with the latest recommendations from the National Academy of Sciences (NAS). And even the Academy's advice--which is up to five years old for some nutrients--may be out of date.

For example, recent studies suggest that high doses of vitamin A may raise the risk of hip fracture and that the latest recommended levels of vitamin K may be too low to protect your bones. And a high dose of vitamin E may make colds worse.

What's more, labels can mislead shoppers. For example, a bottle may say that a multi has 100 percent of the Daily Value for vitamins A, C, and K. What it doesn't say is that the government hasn't changed the Daily Values since the mid-1970s. Experts now recommend more C and K, so 100 percent of the Daily Value is less than a day's worth. And experts recommend less vitamin A, so 100 percent of the Daily Value is more than a day's worth.

To simplify your search for the perfect multi, we've evaluated dozens of brands to find our Best Bites, using different criteria for men and pre--and postmenopausal women. Here's how we separated the best from the rest. You can follow the same steps if you want to check out brands that aren't in our chart.

1

Look for 100 percent Of eight vitamins

A multi is supposed to supplement, not replace, your diet. But it's easier to look for a multi that has a full day's worth of each vitamin and mineral than to try to guess how much you're not getting from your food.

Our Best Bites have at least 100 percent of the Daily Value for thiamin (B-1), riboflavin (B-2), niacin (B-3), vitamins B-6, B-12, D, E, and folic acid. They also have at least 90 mg of vitamin C, which is the new recommended level for men (it's 75 mg for women). That's more than the current Daily Value (60 mg).

2

Limit vitamin A

According to a 2002 Harvard Medical School study of 72,000 women, those who consumed between 4,300 international units (IU) and 6,600 IU a day of vitamin A had a 43 percent higher risk of hip fracture than those who consumed 1,700 IU or less. The risk was greater in women who got even more than 6,600 IU. Only one kind of vitamin A, retinol, was linked to weaker bones. It's found in animal foods (dairy, liver, eggs, etc.). Beta-carotene, which the body converts to vitamin A, is found in fruits and vegetables. It doesn't increase the risk of hip fractures. The vitamin A in supplements can come from retinol (often called vitamin A palmitate or acetate), from beta-carotene, or from a combination of the two. (Check the label. Some simply list vitamin A, which isn't very useful. But many brands also disclose what percentage of their vitamin A comes from beta-carotene. If so, the rest is retinol.)

To protect bones, we limited our Best Bites to no more than 4,000 IU of retinol. But even less would be better, since people also get some vitamin A from their food. Our limit is especially important for women (so far, no studies have been done on men's bones and vitamin A).

Roche Vitamins, a major manufacturer of vitamin A, says that many of the vitamin-makers it supplies have agreed to lower their retinol levels to 2,500 IU. That may make the numbers in our chart outdated by the time you read this, so check your labels.

Some brands have far too much retinol. KAL, Puritan's Pride, Solaray, and Twinlab each sell at least one multi with 10,000 IU. And Now's Vit-Min 75 has 15,000 IU. That exceeds the National Academy's 10,000 IU "upper level" (UL) for retinol, which is the highest safe intake. The UL is based on evidence that more vitamin A may cause liver abnormalities and, if consumed by women of childbearing age, birth defects.

Beta-carotene doesn't cause those problems. But we set a limit of 15,000 IU for our Best Bites because too much beta-carotene may increase the risk of lung cancer in smokers. (Beta-carotene from foods is safe.)

3

Look for vitamin K

In 2001, the National Academy boosted the recommended intake of vitamin K from 80 micrograms (mcg) a day to 90 mcg for women and to 120 mcg for men. Yet only a handful of multivitamins have even 80 mcg.