Adolescence is a time of major growth and change for your teenagers. If they're eating a well-balanced diet of three healthy meals a day that include a variety of fresh fruits and vegetables, dairy products, meat, fish, nuts and whole grains, they probably don't need to take vitamins, unless they have other medical problems. If, on the other hand, your teens skip breakfast often, don't eat according to the ideal diet, , or suffer from an eating disorder, you may want to consult their doctor about the necessity of vitamin supplements.
If your teen is a vegetarian, he or she may need to work out a diet that fills in the missing vitamins and minerals that are usually found in meat. For example, the best sources of zinc and iron are found in meat, fish and chicken. If your teens are willing to eat beans, nuts, seeds and leafy green vegetables such as kale, they can get some zinc and iron that way; but if they're not interested in such exotic fare, they may have to get their minerals via pills. Vegans (strict vegetarians who don't even eat products that come from animals, like eggs or dairy foods) are at risk for insufficient vitamin B12, which is needed for the manufacture of red blood cells.
Due to many teens' erratic schedules and diet, they often have low levels of calcium and vitamin D, iron, zinc, vitamin A, the B vitamins, vitamin C, and folic acid. Teenagers who consume a lot of carbonated drinks may have too much phosphorus in their bodies, which throws their calcium out of balance. If a multivitamin or supplements are prescribed, make sure that they contain 100 percent of the U.S.R.D.A. (U.S. recommended daily allowances) of whatever vitamins and minerals they're lacking; but your teen shouldn't take more than that, as too many fat-soluble vitamins and minerals can build up in the body with toxic results.