Are You Over-Supplementing?

Is every juice carton in your refrigerator labeled “calcium-fortified?” How about the cereals in your cupboard? Are vitamin bottles stacked up like pyramids in your medicine cabinet? We all do it. In our quest for good health, we fill our pantries and refrigerators with a little vitamin and mineral insurance.

But are we overdoing it?

Food is best
“Unless it’s prescribed for you and you have a specific need, don’t take more than a multivitamin,” says registered dietitian Andrea Dunn. She explains that it’s best not to rely on supplements but to get our vitamins and minerals from a wide variety of foods. Good nutrition primarily depends on appropriate food choices. Remember the Food Guide Pyramid from grade school? It demonstrates visually that grains, fruits and vegetables are the foundation foods of a healthy diet. Eat a variety of foods every day and get as close to the food source as possible says Dunn. “If you are going to eat soy, eat soybeans," she says. “The nice thing about using food to get your vitamins and minerals is that so many other things hang out in food, like antioxidants and phytochemicals, which give us protection against cancers and heart disease.”

RDA and supplements
In 1941, the first Food and Nutrition Board established dietary standards for evaluating the nutritional intake of large populations. Separate recommendations were made for different sets of people: women, men, children and pregnant women. The U.S. Recommended Dietary Allowance (RDA) for a nutrient is based on the amount needed to prevent a deficiency. As better scientific knowledge becomes available, the RDA’s are updated every ten years. Keep in mind that you don’t need to eat every nutrient every day because your body stores nutrients for later use. That’s why in "RDA" the “R” stands for “recommended” not “required” and the “D" stands for “dietary,” not “daily.”

If you still aren’t sure you’re getting what you need, most experts agree that a one-a-day type multivitamin/mineral supplement is a good, inexpensive form of nutritional insurance. Choose supplements that provide 100% of the RDA for vitamins A, C, D, E, the B complex vitamins and at least 11 minerals.

Too much of a good thing?
So if you want to take a multivitamin, it’s okay - but don’t overdo it. For example, the RDA for vitamin C, one of the water-soluble vitamins, is 60 mg. Research shows that the body excretes vitamin C if you get over 200 mg. If you’re overdoing it, then “you have expensive urine,” says Dunn. “But that’s the nice thing about the body, it can get rid of some of the higher amounts.”

However, many vitamin megadoses are not used by the body and, if they can’t be excreted, they can cause big problems. For example, high doses of vitamin D and iron can result in kidney damage. Too much Vitamin A can cause diarrhea, headaches, nausea, and possible damage to the liver and bones. Vitamin E, a popular supplement, can interfere with vitamin K and its role in blood clotting.

So, if you’re already taking a multivitamin, should you avoid foods that have artificial fortification?

"In general – no," says Dunn. There is a role for some vitamin fortification. Dunn herself is a fan of calcium-fortified foods. She says that 55% percent of men and 73% of women don’t get enough calcium. So that extra calcium you get with your fortified morning juice is a good thing. And teens need four dairy servings a day. “Unless your child is drinking a quart of milk a day, he or she isn’t getting enough,” says Dunn. “If you’re going to give your children juice, give them one that is calcium-fortified."