Oct. 29, 2010 -- Entire stores, grocery store aisles and websites are dedicated to helping you find the right combination of vitamins and supplements -- the kinds you swallow, the kinds you chew and the kinds you drink.
Although 44 percent of Americans say they use supplements every day -- helping to create the $25 billion dollar industry, many don't understand why they take them or whether they need to take them at all.
Some supplement labels claim that what's inside the products will help guard against illness. Others boldly claim that you're not getting enough nutrients in a day. But for many, supplements may not be the answer to staying healthy.
"If we really look at the data on vitamins and minerals, there isn't a whole lot there," said Dr. Donald Hensrud, associate professor of Nutrition and Preventive Medicine at the Mayo Clinic in Rochester, Minn.
Still, websites by well-known alternative health experts say answers to a few quick online questions about yourself will help them determine a personal combination of supplements that are right for you.
ABC News' chief health and medical editor, Dr. Richard Besser, decided to try a few websites.
"I'm 51 and I'm in good health," said Besser. "I'm a very healthy eater and have a very diverse diet."
In fact, Besser's primary care physician, Dr. Jill Silverman, said Besser did not need vitamins or supplements.
"If you have a varied diet and you're eating fruits and vegetables, you should get all the vitamins through your diet," said Silverman. "Otherwise, I just think you're just wasting your money if you're taking anything extra, and potentially doing some harm."
According to Keith Ayoob, director of the nutrition clinic at the Rose R. Kennedy Center at the Albert Einstein College of Medicine in the Bronx, N.Y., it is possible to overdose on vitamins.
"If you take too much of one, you might offset how another one works," said Ayoob. "Sometimes, minerals don't mix well together."
The U.S. Food and Drug Administration does not regulate safety of supplements as rigorously as foods or medications.
"There isn't a lot of regulation regarding quality control, safety or efficacy," said Hensrud. "It's somewhat of a buyer beware [situation]."
After taking a questionnaire on DrWeilVitaminAdvisor.com, the automated response suggested Besser take a daily antioxidant, daily multivitamin, B-50, vitamin C, omega-3 and a supplement called the Weil Juvenon, all of which he could buy off the site at a cost of $51 for a 30-day supply.
That's about $600 a year, the cost of some gym memberships," said Besser. "I eat well. I exercise regularly. It's just not clear to me why I need any of these products."
"It should be noted that Dr. Weil donates all of his after-tax profits from all supplement sales to the Weil Foundation to support integrative medicine education and research," Larry Tree, cofounder and CEO of Weil Lifestyle LLC, told ABC News in a written statement. "We always follow with the statement that taking supplements does not excuse you from eating a health-promoting diet."
Another site, VitaminID.com, created by the manufacturer of Nature Made vitamins, suggested nine vitamins for Besser -- vitamin C, calcium, fish oil with vitamin E, magnesium, vitamin D, super B and milk thistle, a multivitamin.
"When I see folks taking numerous pills [supplements] a day, I have to wonder about how much they're excluding in their diet," said Ayoob.
Besser said he eats far more than the required two cups of fruit and two and half cups of vegetables a day.
The combination of supplements recommended by VitaminID, also available to purchase through its website, would cost $52 for a month's supply.
"Nutritional supplementation is one small component of a healthy lifestyle and our aim is to educate and offer consumers personalized guidance and information," a representative for VitaminID.com said in a written response to ABC News.
Supplements Show Benefit for Some
While some supplements are marketed to work for a variety of ailments, there's no scientific data to back all of the claims. All women of childbearing age are advised to take folic acid to prevent neural tube defects in their child. However, some studies discredit claims that folic acid and other B vitamins prevent prostate cancer, colon cancer, or heart disease.
For some, however, supplements can be beneficial, said Ayoob.
In fact, only 3 to 4 percent of Americans follow all of the dietary guidelines, according to 2009 position paper published by the American Dietetic Association.
"Some things are difficult to get [from food] for some people," said Ayoob.
Among those are Vitamin D, which most often is gained through appropriate exposure to sunlight, tuna, salmon or fortified milk. Many Americans are deficient in Vitamin D, he said.
Other examples include osteoporosis patients who may need calcium supplements, or smokers who are at higher risk for vitamin C deficiency.
Still, Ayoob said, "You're never going to get from a pill what you get from healthy food."