College students who use vitamins as sources of nutrients often do so because their hectic schedules can force them to eat foods high in convenience but unsavory for their health.

But vitamins can't replace a healthy diet and should only be used as a backup for healthy food choices, experts say.

Peggy Apostolos, an Ingham Regional Medical Center dietitian, said one misconception about vitamins and supplements is that they can replace foods that have the same nutrients.

"People might think that they don't have to eat a healthy diet, and will think, 'If I don't have any protein, I'll just take a multi-vitamin,'" Apostolos said.

That assumption is false because nutrients in vitamins aren't as easily absorbed into the body as the same nutrients in food, she said.

Nutrients in vitamins could pass through the body while nutrients from food would be absorbed.

Also, vitamins do not contain essential protein, fat or carbohydrate, and won't give you the energy that food will, she said.

Eating nutritious food should always come before taking vitamins, with the exception being people who are allergic or intolerant to certain foods, said Ronda Bokram, registered dietitian and health educator at Olin Health Center.

Since the body can store a limited amount of each nutrient, excess amounts of nutrients don't necessarily lead to any improvements, Apostolos said. People see the most results from vitamins, when there is a problem to be fixed, she said.

"If there is a deficiency it can be treated, but if your stores are full, taking more isn't necessarily going to make (a health problem) better," she said.

John Snyder, owner of Foods for Living, said unless you have a food allergy that keeps you from certain nutrients, people should find the right nutrients in their foods.

Even the common belief that vitamin C will eliminate colds faster is more of a preventative measure than an actual treatment, he said.

But taking vitamin C with a healthy diet will strengthen the body's ability to fight a cold or virus.

"The better your health is the less you are impacted," Snyder said. "So if you are exercising and taking a one-a-day vitamin, you're going to handle a cold a lot better than a person who goes to McDonald's three times a week."

Another misconception is that because vitamins are natural, they cannot cause problems if taken in large doses or with other medication.

But you should always check with a doctor or pharmacist to ensure that a vitamin or supplement will not interfere with your body's ability to absorb other medicines you are taking, Snyder said.

"You have to be really careful — use a cross-checker to make sure the pharmaceutical is not compounding or negating the effect of the natural supplement," he said.

There also are vitamins that have nutrient doses much higher than the recommended daily amount, which add to the misconception that — when it comes to vitamins — more is always better, Bokram said.

"You shouldn't buy a product that has more than the recommended daily percentage of a nutrient," Bokram said. "People don't understand that when you get things in larger doses it's like a drug in its effect."

She said buying vitamins can be a waste of money for those who don't need to take them.

"This is where the mentality of our culture comes into it — more is better," Bokram said. "You're basically paying for expensive urine."