Nutritionist Samantha Heller of New York University
Conversely, you can overdo it on some nutrients if you use pills.
What's more, compounds work together and are integral to each other's optimal function in the body. So, it's important to keep them in balance in the body; too much or too little of any one thing can knock that balance out of whack.
Simply put, Heller says, when faced with the choice of getting your nutrients from supplements or food, "Go for the food. It has to be the food.
"Food has so many phytochemicals, vitamins and minerals, all packed together in that perfect package, to keep your body healthy. We just need to eat healthfully and have a variety of healthy food.
"You'd be a lot healthier and have a happier body. You want to maintain that internal balance of all vitamins and minerals and phytochemicals. That will keep you healthy, make you look good and fight off disease."
Heller says we need 1,000 to 1,500 milligrams of calcium daily.
"To get that," she says, "you have to take four (standard supplement) pills. You don't want to have to do that. You want to get it in your food. If you have a cup of yogurt during the day, if you put some skim milk on fortified cereal, or drink orange juice, you'll get what you need."
The recommended daily amount of vitamin D varies, from 200 to 600 international units, "So 400 is fine, but you want to get it from food. Three ounces of salmon, a cup of skim milk, also cereals are fortified with these vitamins."
Vitamin E is "very important," Heller says. "We tend to over-supplement with vitamin E. A study came out this week saying Americans are taking too much of it from pills. You can have an ounce of sunflower seeds, a cup of spinach. Throw the sunflower seeds in your spinach and you'll get what you need."
Another example: iron. "For adult men and post-menopausal women," Heller says, "we're not worried. But for young adults, women of child-bearing age, athletes, we need to get more iron. But too much iron can be toxic. You have to be very careful about that. A bowl of fortified oatmeal is 10 milligrams, almost what you need for the day, namely, 18 milligrams. Lentils, prune juice, soybeans, all good for you."
Most of us aren't getting the magnesium we need, Heller adds. It's important for our hearts, muscles, and nerve conduction. "Have a peanut butter and jelly sandwich for lunch with a glass of milk," Heller suggests. "Have some halibut, and cashews. You'll get the magnesium you need for the day."