Analysis of serum zinc levels in healthy Japanese children under the age of 10

BACKGROUND: Children who primarily consume starch-heavy diets, which tend to be high in phytic acid that inhibits zinc absorption and low in zinc-rich animal protein, are at increased risk of zinc deficiency. However, there is limited research addressing this issue. This study aimed to evaluate serum zinc levels in healthy Japanese children under 10 years of age. METHODS: A retrospective review of medical records from children who underwent preoperative examinations for inguinal or umbilical hernia surgery between January 2021 and December 2023 was conducted. Children with conditions such as prematurity, low birth weight, asthma, or dietary restrictions were excluded. Hypozincemia was defined as serum zinc levels < 80 μg/dL. This study analyzed the occurrence rate of hypozincemia and relationship between hypozincemia and contributive factors. RESULTS: In this study, 187 cases were eligible for analysis, with a median age of 45 months. The median serum zinc level was 74.0 μg/dL, with children aged 6-10 years showing higher levels. A weak positive correlation was observed between the serum zinc levels and age, serum albumin levels, and hemoglobin levels. Hypozincemia was observed in 74.3 % of studied cases. Significant factors associated with hypozincemia included low serum albumin levels and the timing of sample collection. CONCLUSION: Based on Japanese standards, approximately 75 % of healthy Japanese children exhibited low serum zinc levels, suggesting a potential risk of zinc deficiency. It is recommended that screening, monitoring, and supplementation of zinc be considered, particularly for younger children or those with increased zinc needs.