Intakes of vitamin C, vegetables and fruits: which schoolchildren are at risk?

Abstract

Objective: The purpose of this study was to determine vitamin C intakes among American schoolchildren. We investigated the leading sources of vitamin C in children's diets, the leading vegetables and fruits consumed by children and differences in dietary intake associated with vitamin C consumption.

Methods: Data from 1,350 7- to 12-year-old and 908 13- to 18-year-old schoolchildren were obtained from the 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII). The children were stratified by age and gender and then split into three vitamin C consumption groups based upon two 24-hour recalls: low (0 to 30.0 mg), marginal (30.1 to 59.9 mg), and desirable (>60.0 mg). Data were analyzed by tabulation and by ANOVA followed by post hoc Scheffe's test. Outcome measures included food groups and energy-adjusted intakes of micro- and macronutrients.

Results: Among the 7- to 12-year-olds, 12% of boys and 13% of girls had mean vitamin C intakes that were less than 30 mg/day, and, among 13- to 18-year-olds, 14% of boys and 20% of girls had low vitamin C intakes. In addition to consuming significantly more vitamin C, children with desirable vitamin C intakes also consumed significantly more (p <0.001) energy-adjusted folate and vitamin B6; children with low vitamin C intakes tended to have significantly greater (p <0.001) energy-adjusted intakes of fat and saturated fat. Children with desirable vitamin C intakes consumed significantly more (p <0.006) high-vitamin C fruit juice, low-vitamin C vegetables and whole milk. Children with low vitamin C intakes on average consumed two daily servings of vegetables and fruits, of which less than 1/5 of a serving was citrus, while children with desirable vitamin C intakes consumed an average of one daily serving of citrus.

Conclusions: A considerable number of children drastically under-consumed vitamin C and total vegetables and fruits. Overall, children with desirable vitamin C intakes had healthier diets, including more milk and vegetables, than did their peers with low vitamin C intakes. Health care professionals should continue to promote at least five daily servings of vegetables and fruits and should advise parents that at least one of these should be rich in vitamin C.