A balanced diet is still the best way for children to receive the nutrients they need, according to Sheri Zidenberg-Cherr, an assistant research nutritionist at UC Davis. "When parents rely on vitamin or mineral supplements, the chance of overdoses resulting in toxicity increases," Zidenberg-Cherr says. "And particularly high levels of individual vitamins or minerals can cause imbalances." Certain children who are especially at risk for nutritional deficiencies may benefit from vitamin/mineral supplements. These include pregnant teen-agers and children who live in low-income households, have poor appetites, follow fad diets or are strict vegetarians. For these children, Zidenberg-Cherr suggests a dietary evaluation by an appropriate health-care professional along with an education on the proper food choices to ensure dietary adequacy. If supplements are used, Zidenberg-Cherr suggests an over-the-counter multivitamin and mineral preparation for children with a label that shows nutrient amounts not exceeding 100 percent of the U.S. Recommended Daily Allowance. Fluoride supplements may be necessary if a family's water supply contains less than .3 parts-per-million of fluoride.