Higher risk of zinc deficiency in New Zealand Pacific school children compared with their Māori and European counterparts: a New Zealand national survey

Abstract

Few multi-ethnic national surveys have examined Zn nutriture, despite its importance for optimal growth and development during childhood. We assessed the Zn status of urban and semi-urban children aged 5-15 years from three ethnic groups in New Zealand (NZ) in the 2002 Children's National Nutrition Survey and investigated the factors predisposing them to Zn deficiency. In a 10-month cross-sectional survey, Pacific and Māori children were over-sampled permitting ethnic-specific analyses. Anthropometry, serum Zn and Zn intakes via 24 h recalls were measured. Anthropometric z scores were highest in Pacific children. Overall, mean adjusted serum Zn at 11 years was for males and females, respectively: 11·9 (95% CI 11·5, 12·3) and 12·5 (95% CI 12·0, 12·9) μmol/l in NZ European and Other (NZEO) children (n 395); 11·9 (95% CI 11·4, 12·4) and 12·0 (95% CI 11·4, 12·5) μmol/l in Māori children (n 379); and 11·5 (95% CI 11·1, 11·9) and 11·4 (95% CI 11·1, 11·8) μmol/l in Pacific children (n 589). The predictors of serum Zn were age, serum Se and sex for NZEO children; serum Se and age for Pacific children; and none for Māori children. Pacific children had the highest prevalence of low serum Zn (21 (95% CI 11, 30) %), followed by Māori children (16 (95% CI 12, 20) %) and NZEO children (15 (95% CI 9, 21) %). Prevalence of inadequate Zn intakes, although low, reached 8% for Pacific children who had the lowest Zn intake/kg body weight. Pacific boys but not girls with low serum Zn had a lower mean height-for-age z-score (P < 0·007) than those with normal serum Zn. We conclude that the biochemical risk of Zn deficiency in Pacific children indicates a public health problem. However, a lack of concordance with the risk of dietary Zn inadequacy suggests the need for better defined cut-offs in children.