Objectives: This study attempted to measure and assess the intakes by Japanese pre-school children of Fe, Zn, Mn and Cu which affect their health including the taste, bone strength and bone metabolism.
Methods: The total subjects were 90 children aged 3-5 with 30 in each age group (15 boys and 15 girls). Their duplicate diet samples were collected for 3 separate days for each child during 1999: summer, autumn and winter. The preserved samples were wet-ashed with conc. nitric acid and 30% hydrogen peroxide, diluted with 0.5M nitric acid to 50ml and determined by the atomic absorption method. The data were analyzed using the SPSS 11.0J. Normality was assessed using the Shapiro-Wilk test. The Kruskal Wallis test was used for age differences, the Mann-Whitney test for sex differences, and the Spearman Rank Correlation Coefficients for correlation.
Results: Seasonal differences were seen in each daily dietary intakes of Fe, Zn, Mn and Cu (all p=0.000), age differences in Zn and Mn (p=0.003, p=0.005) and sex differences in Zn (p=0.031). The season mean daily intakes were Fe: mean 3.1 (SD: 0.94, range: 1.5-6.1) mg, median 3.1 (25-75 percentile: 2.4-3.6) mg, Zn: 4.0 (1.0, 1.7-7.2) mg, 4.0 (3.4-4.7) mg, Mn: 1.4 (0.41, 0.63-2.7) mg, 1.3 (1.1-1.6) mg, Cu: 0.47 (0.15, 0.21-1.0) mg, 0.45 (0.35-0.56) mg, respectively. The mean dietary intake was 1305 (SD: 245, range: 761-2003) mg, median 1283 g (1141-1471), which had significant correlations between the 4 elements. (Spearman r=0.55, 0.67, 0.58, 0.56, all p=0.000)
Discussion: As there are few studies on the dietary intakes by Japanese children, it is important to determine their intakes of trace elements to be used as basic information.
Conclusion: The mean daily intakes of Fe, Zn and Mn were lower than EAR (or AI ) of the 7th Dietary Reference Intakes.