Preteens are gearing up for some big changes in their bodies, so proper nutrition is important. Getting enough vitamins and minerals helps your preteen develop and helps keep him healthy and strong. You may wonder if your preteen needs a vitamin supplement during this time. The American Academy of Pediatrics doesn't recommend a daily multivitamin for kids, but some children at risk for a vitamin deficiency may benefit from one.

Balanced Diet

A balanced diet should provide all of the vitamins your preteen needs, according to the American Academy of Pediatrics. The one area of concern for healthy kids is vitamin D; many kids who don't drink milk may be lacking this vitamin. Offer your preteen a variety of fruits, vegetables, grains, protein and dairy choices every day to ensure that she gets the vitamins she needs to stay healthy. Limit sugary, sweet snacks in favor of things like fresh fruit and whole grain muffins.

Vitamin D and Supplements

The main source of vitamin D for kids is fortified cows' milk. If your preteen doesn't like or can't drink milk, he may be at risk for a vitamin D deficiency. Many multivitamin supplements include vitamin D, and according to Dr. Sanjay Gupta, giving a healthy child a vitamin supplement probably won't hurt. Some multivitamins are fortified with calcium and iron, which are important to preteens' development, especially girls. Talk to your doctor about multivitamin supplements if you think they might benefit your preteen.

Important Vitamins

Vitamin D is important for building strong bones and teeth and helps your body absorb calcium. You can get vitamin D from milk, fortified cereal, fish, eggs and liver. Vitamin E helps keep tissues and cells from getting damaged. Look to whole grains, green leafy veggies, egg yolks and nuts for vitamin E. Vitamin K helps blood clot -- this one is important for all those daredevil preteens out there. Serve broccoli with cheese, other dairy products, and leafy greens to help your preteen get enough vitamin E. If you want to avoid getting sick, get plenty of vitamin C. It helps boost your immune system, and it also keeps your gums and muscles healthy. Vitamin C is found in citrus fruits, bell peppers, kiwi fruit, cantaloupe, strawberries, broccoli, cabbage and tomatoes. B vitamins provide your body with energy and help oxygen get to your red blood cells. To get plenty of B vitamins, eat whole grains, lean meats, fish, seafood and poultry, beans, eggs, more of those leafy green veggies, and dairy products like yogurt. Vitamin A helps your eyes work their best and also helps keep your immune system healthy. Fortified milk, liver, orange-colored vegetables and again, those great leafy greens are all sources of vitamin A.

Who Needs a Supplement?

Dr. Gupta said that most kids won't be hurt by taking a supplement, but can get the majority of their vitamins through a healthy diet. Some preteens might need a supplement, though. These include kids who can't or won't eat enough, due to illness, sensory issues or simply being very picky; are on a vegan or vegetarian diet and aren't getting enough nutrients (some vegetarians and vegans can get what they need through diet alone, though); or have a medical condition such as food allergies or diseases of the digestive system that prevent them from being able to get or absorb enough vitamins. If your preteen daughter has started her menstrual period and bleeds heavily, she may also need to take a vitamin. If you're concerned about your child's diet and think she might need a vitamin supplement, talk to her pediatrician.