In an ideal world, everyone would get all the nutrition, all the vitamins and minerals they need from the food they eat. But…
"That's wishful thinking," says Chicago-based dietitian David Grotto, RD, the author of 101 Foods That Could Save Your Life and a former spokesman for the American Dietetic Association.
How wishful? Very, especially for men. According to the USDA, men aged 31 to 50 need to eat 350% more dark green vegetables and 150% more fruit per day in order to meet federal dietary guidelines. In fact, men have deficits in nearly every nutritional category. Meat and beans are an unsurprising exception.
To Supplement or Not to Supplement
What's a guy to do? Pop a vitamin pill and leave it at that? Not so fast, says Howard Sesso, ScD, MPH, an associate professor of medicine at Harvard Medical School and project director of the Physicians' Health Study II, which followed nearly 15,000 male doctors over the course of 10 years to evaluate the potential health benefits of four of the most popular vitamins: C, E, beta carotene, and multivitamins.
"Studies over the last few years have suggested that individual supplements don't have benefits," Sesso tells WebMD.
In one large study, Sesso and his fellow researchers found that neither vitamin E or C lowered the risk of cardiovascular disease. That study was published in The Journal of the American Medical Association (JAMA) in November 2008. In a study published in JAMA in January 2009, the same team reported that taking supplements of vitamins E and C did not lower a man's risk of developing prostate or total cancers.
However, other studies have been more positive. PHS II researchers reported in 2007 that beta carotene supplements might have brain benefits if taken regularly over many years. Beta carotene, taken along with vitamins C and E and zinc, might also slow the progression of age-related macular degeneration, a cause of blindness.
So, where does that leave us? Still short of certainty.
"You have to look at the totality of evidence in order to come up with recommendations," says Andrew Shao, PhD, senior vice president of scientific and regulatory affairs at the Council for Responsible Nutrition, a trade organization that represents the nearly $25 billion-a-year supplement industry.
And there's still plenty of evidence to be gathered.
Research into supplements continues at a brisk pace. Sesso, for example, is nearing the end stages of a study on multivitamins.
One possible reason that individual supplements fared so poorly in trials – and why food sources are widely held to be superior to supplements – is because their benefits may depend on the interactions of a particular food's components. In other words, the whole may be greater than the sum of its parts. Take strawberries, a rich source of vitamin C and other nutrients, Sesso says.
"How do you replicate [a strawberry] in a supplement?" Sesso says. " You have to put it all together in order for it to be reflective, but that is difficult. To take something and replicate it perfectly – that is the challenge.”
Multivitamins, he says, might prove to be one way to gain the advantages of some of the complex interactions found in food sources.
"They potentially reflect food-based sources," Sesso says. "They have the potential to offset deficiencies [found in individual supplements]. It's a very enticing concept and it makes sense.”
Sesso estimates that his team will have "some definite results" within the next few years.
Grotto isn't waiting. He already recommends a daily multivitamin to the majority of his clients. But not without caveats.
"People need to recalibrate their expectations of what a multi can do," Grotto says. "They are supplements, not replacements. The dietetic mantra remains ‘get your nutrition from food.'"
That said, Grotto advises his male clients to pick a multivitamin that's specially formulated for men. That means one with little or no iron. Shao agrees.
"Most men get enough iron," Shao says. "The body… doesn't have a good way of getting rid of excess iron.”
Grotto finds that most adults and children in his practice come up short when it comes to vitamin D. "When it comes to recommendations, multivitamins and additional vitamin D are a recurring theme," he says.
But remember: Each man's needs are his own, so you should consult a doctor or dietician to determine what's best for you.
"Maintain an ongoing dialogue with your health care provider, focusing on using supplements and any conditions you might be concerned with," Shao says.
Too Much of a Good Thing
Whatever benefits supplements may prove to impart, you still need to be careful about just how much you take. More does not mean better. In fact, taking too much of some vitamins can cause serious problems. An excess of vitamin A, for example, can damage your liver. Although this is rarely a problem from food, supplements make excess amounts easier to consume.
"For vitamin A, toxicity is very well established at high levels," Shao says. "For most nutrients, there is a very wide range between what can be found in high-potency supplements and toxicity… Nutrients are native and essential to the body, and most have subtle or no side effects even up to extremely high levels. With Vitamin A, there's not as much of a safety range.”
To be on the safe side, Grotto says, "I steer people away from high-potency vitamins.”
Food for Thought
Despite the debate, nearly half of American adults take some form of supplement. Grotto says that a recent survey of dietitians revealed that as many as 96% of respondents were doing the same.
"The promise of supplements is to reduce the risk of disease and maintain health and wellness," Shao says. But he says a good diet "should take a food-first approach.”