"I keep them in my cubicle so I don't forget to take them," said Stewart, a telecommunications worker in Washington. At 27, Stewart found he was putting on a few pounds, so he recently began body building and working out regularly, which in turn has spurred his interest in vitamins and minerals.
Jacquie Felegie, an interior designer from Springfield, began taking daily vitamins 18 months ago after reading about their benefits in the Nutrition Action Newsletter published by the Center for Science in the Public Interest. Felegie, 41, opts for vitamins and minerals that are specially formulated for women and designed to be taken twice a day. "I figured it can't hurt to take them," she said.
Irwin Edlavitch, 64, became a convert to daily vitamins at the suggestion of his personal trainer. "And my doctor agreed," said Edlavitch, an executive with Parking Services International. "I take them to feel better," said Edlavitch. "But I can't tell you what I take. They are three vitamin pills. That's all I know."
Convinced of their benefits, a growing number of Americans are turning to vitamins and minerals to help keep them healthy. The latest federal National Health and Nutrition Examination Survey (NHANES) found that 40 percent of Americans had taken a vitamin or mineral supplement during the past month.
Sales of vitamins and minerals were already on the upswing when the 1994 Hatch Act eased regulations regarding sales of supplements and established an Office of Vitamin Supplements at the National Institutes of Health to boost research.
Since then, consumer sales of vitamin supplements have continued to grow. In 1997 they totaled nearly $5 billion--9 percent higher than in 1996, according to the Nutrition Business Journal in San Diego, Calif. Retail sales of minerals rose 18 percent in 1997 to over $1 billion annually, according to the journal. About 2 million Americans who regularly bought dietary supplements spent more than $50 a month on vitamins, minerals or herbs, while 23 million shelled out an average of $20 a month on supplements, according to the NBJ.
Yet there are many unanswered questions about vitamins and minerals: Do pills really provide the same beneficial ingredients as food? Are the vitamins and minerals in supplements and fortified food absorbed as well as those occurring naturally in other foods? Does it matter what time of day vitamins and minerals are taken? Does it matter whether they're taken on an empty stomach or consumed with food? And is it preferable to be a purist and space out single doses of vitamins and minerals throughout the day, or better to take a multivitamin that covers all the bases?
Even experts struggle to make sense of it all, because the scientific research is so mixed. "I can't tell you how complicated and confusing this can be," said Judith Stern, professor of nutrition and internal medicine at the University of California at Davis. Not only are benefits sometimes overblown, but the side effects may also be overlooked.
Stern had a friend who began bruising soon after he started taking 800 I.U. a day of vitamin E--about twice the amount that has been recommended to help reduce the risk of heart disease. What this friend, a physician, forgot is that vitamin E reduces blood clotting time and can cause bleeding. "These vitamins are not completely benign," Stern said.
But with each new study touting the latest benefits of vitamin and mineral supplements, "the consumer gets bombarded with more information," said Vishwa Singh, director of human nutrition research for Hoffmann-La Roche, one of the leading vitamin manufacturers. "They're confused and they don't know what to do."
EAT RIGHT AND TAKE VITAMINS
But the rules have changed in recent years, a reflection of new scientific data showing the added importance of key vitamins, especially folic acid, vitamin B12 and calcium. Even critics such as Mount Sinai School of Medicine professor Victor Herbert, author of "The Vitamin Pushers," a book highly critical of the vitamin industry, says that certain supplements have a place at the table.
"Call me an 'alleged' vitamin opponent, because I've actually been pushing supplements of vitamin B12, calcium and folic acid for the last 15 years," Herbert said.
The National Academy of Sciences now largely agrees with him.
As part of its periodic review of necessary nutrients, the Food and Nutrition Board of the National Academy of Sciences recently raised the recommended daily intake of folic acid for fertile women to cut the risk of some birth defects. They also recommended vitamin B12 for those over 50 and calcium for children and older women. The academy's board suggested that these special vitamin needs may not be met easily through food alone.
In fact, a growing number of nutrition experts think that "people ought to eat right and take a multivitamin," said Emory University visiting professor Godfrey P. Oakley Jr.
In an editorial on the importance of multivitamins published last year in the New England Journal of Medicine, Oakley noted that since the mid-1970s, 25 percent of American adults have regularly taken a daily multivitamin supplement. "The current evidence suggests that people who take such supplements and their children are healthier," Oakley wrote. "This evidence raises the question of whether physicians and other health care professionals should recommend that all adults take a multivitamin daily."
And it's hard to argue with the growing body of scientific evidence pointing toward benefits of vitamin use. For example, the Harvard School of Public Health recently reported findings from its ongoing study of 89,000 nurses that women who took a daily multivitamin for at least 15 years were 75 percent less likely to develop colon cancer than those who did not.
MULTIVITAMINS PRO AND CON
While a multivitamin may not be all things to all people, advocates say that it provides a good nutritional starting point. "Taking a balanced multivitamin supplement is really one of the single most important things that people can do," said Richard Rivlin, program director of the clinical nutrition research unit at Memorial Sloan-Kettering Cancer Center in New York.
Most nutritional experts think that a multivitamin can't hurt as long as no one expects it to perform miracles. Don't expect, for example, to make up for eating a lousy diet by popping a vitamin supplement. Nor can vitamins and minerals compensate for drinking too much alcohol or smoking cigarettes or never exercising.
But a standard daily multivitamin containing roughly 100 percent of the recommended dietary intake for vitamins and minerals is still a simple and relatively inexpensive way to buy nutritional insurance, according to most experts. "It's not only rational," said John Hathcock, director of nutritional and regulatory science at the Council for Responsible Nutrition, "it would be irrational not to take one."
Just ask Bonnie Liebman, director of nutrition at the Washington-based Center for Science in the Public Interest. "We need to get away from this either-or mentality," Liebman said. "The solution is just to tell people that they need to do both: eat a good diet and take a multivitamin. Health-conscious people have already gotten that message."
MORE THAN A MULTIVITAMIN
Critics note that there is little information about the absorption of the various ingredients in multivitamin preparations. Nor does anyone know whether the 24-hour cycle for taking multivitamins is best. "You could well argue that for some nutrients it may be that every 10 days is better, or maybe it's every three weeks or whatever," Rosenberg said. "The notion of taking a multivitamin daily is not so much based on physiology as convenience."
There is also evidence suggesting that less is more when it comes to multivitamins. Those products that contain 20 different vitamins and minerals are convenient to take but are also more likely to interact and potentially cancel each other out. For example, many multivitamins now offer vitamin C and calcium. But calcium attaches like a magnet to minerals such as iron, zinc and copper and reduces their absorption by the body; vitamin C, on the other hand, increases the absorption of iron and folic acid.
"By mixing [a large variety of minerals and vitamins] you may actually reduce the amount that gets into the body," said Benjamin Caballero, director of the Center for Human Nutrition at the Johns Hopkins University School of Public Health.
For this reason, Caballero and others advise taking multivitamins with the lowest number of ingredients. "One of the most popular combinations contains antioxidant vitamins E and C, [and the minerals] zinc, selenium and manganese. There are at least two to three preparations like this that are quite good."
TAILOR VITAMINS TO SPECIAL NEEDS
Then the role of vitamin and mineral supplements expanded into a kind of "health" insurance. "Lifestyles were going through a transition," Singh said. "And the result was that people without understanding fully, with some minimal data indicating benefit, started to use supplements as a kind of protective insurance."
Now vitamin and mineral supplements are entering a new, more pro-active era in which they not only guard against the possibility of illness but are employed directly toward the prevention of heart disease, cancer, osteoporosis, cataracts and macular degeneration. "Even though the data are still not accurate to determine the exact level of nutrients [for optimal health], we are discussing in detail for the first time what seems to be a role for vitamins and minerals," Singh said.
With this change comes a new emphasis on vitamins tailored to individual needs, rather than a broad multivitamin cocktail. "If what you want is more vitamin E or vitamin D or B12, why do you have to take all the rest?" said Tufts University's Rosenberg. "There may be a lot of stuff in the [multivitamin] cocktail that has nothing to do with the reasons you need to take the vitamins."
Iron is a good example. It's an important mineral for children and for women of childbearing age. But it can produce iron overload in men and in post-menopausal women and potentially accelerate heart disease. So why take a multivitamin that includes iron unless you need it?
Habits can also help determine the need for vitamins. Intense and repeated physical activity can increase the need for thiamine. Oral contraceptives can boost the requirement for folic acid, as can the drug, methotrexate, prescribed to treat cancer and arthritis. Cigarette smoking increases requirements for vitamin C by about 100 milligrams per day, according to Mark Levine, chief of the molecular and clinical nutrition section at the National Institute of Diabetes and Digestive and Kidney Diseases in Bethesda. Extra B vitamins are needed by those who consume a lot of alcohol to help compensate for interference with the absorption of these vitamins and to help protect neurological functions against alcohol damage.
Studies in recent years have also pointed to benefits of taking folic acid to help prevent colon cancer; vitamin D to help absorb calcium and reduce the risk of osteoporosis; vitamin E to reduce the risk of heart disease.
Still, experts caution consumers not to swallow the latest vitamin news without a healthy dose of skepticism. They advise consulting a nutrition-savvy health professional who "can do a health profile and narrow down the benefits that you would get from a few vitamins," Cabellero said.
"It's just remarkable how these things [vitamins and minerals] get a free ride," Rosenberg said. "People think if they are vitamins that they must be good for you and they think if they are vitamins, they belong in a pill not in your food."
Health officials also stress the importance of eating a well balanced diet. The five servings a day of fruits and vegetables recommended by the federal government guarantees the daily recommended intake of vitamin C, about 250 milligrams.
"If that's what you do, you don't need to worry about taking vitamin C pills," said NIH's Mark Levine.
The other benefit of getting vitamins and minerals first from food is that study after study shows that diets rich in fruits and vegetables help lower the risk of cancer and may also help protect against heart disease. Whether those same benefits can be gained from simply popping vitamin and mineral pills is not certain. Scientists suspect that there are special interactions that occur in foods that may not be duplicated by taking pills alone.
That's why a well-balanced diet, Rosenberg said, is still "the best way to get [most] vitamins and minerals."
WHAT'S THE LIMIT
The Institute of Medicine's Food and Nutrition Board addressed that question when they began the long task of revising the recommended daily intake for vitamins and minerals. Tolerable upper intake levels have been set so far for calcium, phosphorus, magnesium, vitamin D, fluoride, thiamine, riboflavin, niacin, folate and choline. (Other vitamins and minerals are being reviewed. Where insufficient scientific evidence exists to set new upper limit, the National Academy has agreed not establish .)
For more information, contact the National Academy of Sciences
NOT QUITE AS SIMPLE AS A-B-C
It may take a doctorate in nutrition to know all the permutations. Even then, new research is rewriting the rules every year. Manufacturers say interactions are very unlikely to occur in multivitamins and are mostly confined to megadoses of the fat-soluble vitamins, A, D, E and K.
Multivitamins that have ingredients that significantly interact "won't pass FDA [Food and Drug Administration approval]," said Vishwa Singh, director of Human Nutrition Research for Hoffmann-La Roche, one of the leading vitamin manufacturers. "You have to prove at the time of sale that 100 percent of the ingredients are still there. Those things are taken care of."
For consumers who take vitamins and minerals, here are some guidelines to make sure you're getting, and absorbing, what you need.
Try to take vitamins at about the same times every day. That goes for a multivitamin tablet as well as individual vitamins and minerals. Making them part of a daily routine means that they don't simply sit on your shelf unused. "If you don't remember to take a vitamin, the amount you absorb is zero," said Johanna Dwyer, a nutrition researcher at the Tufts University School of Nutrition and Medicine.
Don't take a handful of pills at one time. Since vitamins and minerals often interact, which can significantly decrease absorption, experts advise staggering supplements throughout the day. Set up a regular schedule for each one and take some at breakfast, some at lunch, some at dinner.
Try not to take calcium at the same meal with multivitamins or with supplements containing either iron or zinc, since calcium blocks their absorption. While it may not make a big difference once in a while, "if you are taking a lot supplementary calcium, it may be interfering with iron absorption, and that's not a very good trade-off," said Irwin Rosenberg of Tufts University.
The same is true for interactions between calcium and multivitamins. "So it might be good not to take calcium within one to two hours of taking a multivitamin," said John Hathcock of the Council for Responsible Nutrition.
Avoid the exotic. A growing number of vitamin products now often include herbs such as echinacea and other botanicals that promise to deliver a wide range of health benefits but have little scientific evidence to back their claims. "There are so many different brands and combinations that you want to avoid anything strange, particularly natural products that have herbs and unregulated substances with multivitamins," said Benjamin Cabellero, director of the Center for Human Nutrition at Johns Hopkins University's School of Public Health and Medicine in Baltimore.
Take adequate amounts, but not too much. Forget the megadoses. There is no scientific proof that they help, and there is growing scientific evidence that they may cause harm.
Simple is best. A whole variety of supplements is now available in timed-release or sustained-release forms. They often cost more than standard vitamins. But an expert panel recently convened by the National Academy of Sciences found no benefit to their use.
Nor does it make a difference "whether you take these vitamins at the beginning or at the end of the meal," said Robert Russell, also of Tufts. "The idea of these tablets is that if you flatten out the absorption curve you will get a more sustained effect," Rosenberg said. "But there's no evidence that a sustained effect is better for vitamin nutrition."
Consider your stomach. Some vitamins and minerals are absorbed best on an empty stomach, but they can also cause nausea or stomach irritation when they are taken without food--the reason that many experts advise taking most supplements with food. Iron and calcium are both better tolerated with food, although their absorption is slightly decreased.
Fat soluble vitamins--A, D, E and K--are better absorbed with food, especially meals containing some fat. "Since it's hard to get a totally fat-free meal, it doesn't matter whether you take them with breakfast, lunch or dinner," said Jeffrey Blumberg, at Tufts University.
© Copyright 1999 The Washington Post Company