Where Do Teenagers Get Their Vitamins?

ABSTRACT & COMMENTARY

Synopsis: Fortified breakfast cereals, which are consumed by a high proportion of teenagers in Northern Ireland, make a significant contribution to micronutrient intake.

Source: McNulty H, et al. Nutrient intakes and impact of fortified breakfast cereals in schoolchildren. Arch Dis Child 1996;75:474-481.

Food intake of a random sample of more than a thousand Northern Ireland school children 12 and 15 years of age was obtained by hour-long interviews conducted by trained field workers. The sample accounted for about 2% of all Northern Ireland children this age. The calorie and nutrient intakes were calculated from the recorded dietary intakes using a computerized dietary analysis program. Daily intakes of several micronutrients were below the Lower Reference Nutrient Intakes (LRNI). Ninety-two percent of children had low levels of folate intake; 23% had low riboflavin intakes; 13% had low niacin intakes. Twenty-six percent of girls had low intakes of iron, and 14% had low intakes of calcium. The percentage of subjects with overall micronutrient intake below the LRNI decreased with increasing intake of fortified breakfast cereals. Among children consuming 20 g/d or more of cereal—at least one serving per day—there were few subjects with low daily intakes. These results show the potential of fortified breakfast cereals as vehicles for improving nutritional intakes of adolescent school children. (In the UK, dietary requirements are set by the LRNI as opposed to the RDA [Recommended Dietary Allowance] used in the United States. The RDA is, in general, much higher than the LRNI.)

COMMENT BY HOWARD A. PEARSON, MD, FAAP

This study should be of interest to pediatricians who care for teenagers and worry about their diets and nutrition. McNulty et al point out that over the past decades there has been a trend away from "conventional" family meal times toward dietary habits characterized by informal eating and frequent snacking with snack foods. Snack foods may contribute up to one-third of total energy intakes of adolescents. The authors found that the diets of many 12- to 15-year-olds were deficient in micronutrients, especially folic acid. Eighty to ninety percent of these schoolchildren reported that they ate fortified breakfast cereals, and many of these ate more than one serving per day.

One of the great nutritional triumphs of the past 20 years has been the marked reduction of iron-deficiency anemia of infancy by the fortification of infant formulas.1 This worked because the vehicle for fortification (formula) was "targeted" at an at-risk population as previously noted. There is interest in increasing the dietary content of folic acid and iron in the diet of adolescents and young adults to prevent neural tube defects2 and iron deficiency.3 Breakfast cereals may be the vehicle to address a target population of adolescent school children.

It should be emphasized that this study was only a nutritional assessment. There are no data on the clinical implications of these marginal intakes of micronutrients; nor are there in vivo measures, such as RBC folate levels in children consuming less than the LRNI.

Is this study relevant to American school children? While most of us have considered breakfast cereals (particularly the sweetened and flavored varieties) to be a kind of junk food, it may be time to consider these more seriously as a targeted vehicle for delivering specific nutrients to a high risk population—our adolescents.

References

1. Yip R, et al. Declining prevalence of anemia among low income children in the United States. JAMA 1987;258:1619-1623.

2. Elsas LJ. Folic acid and the prevention of NTD. Pediatr Adolesc Med Rep 1996;1:14-15.

3. Pearson HA. Iron treatment improves verbal learning and memory of non-anemic but iron-deficient adolescent girls. Pediatr Adolesc Med Rep 1997;1:93.