Mother-child correlations in hair mineral profiles in Japan: Insights from a cross-sectional study

Despite the importance of mineral consumption in the shared health of mothers and their preschool-aged children, few studies have been conducted on both groups simultaneously, and data on parent-child correlations in hair mineral concentrations remain limited. Therefore, we conducted a cross-sectional study involving 127 Japanese mother-child pairs (children aged 3 years) to investigate correlations in hair mineral concentrations and their associations with dietary intake. Hair samples were analyzed using inductively coupled plasma mass spectrometry. Strong positive correlations were observed between mothers and children for both essential elements (e.g., Cu, Cr, Zn, Mo) and toxic elements (e.g., Hg, Pb, Cd, Al), with particularly robust associations for Cu, Cr, Hg, and Pb. However, dietary mineral intake showed no consistent association with hair concentrations. Inter-element correlations, such as Na-K, Mg-Ca, Mg-Sr, Mn-Fe, and Cd-Pb, were consistently observed in both groups, suggesting shared physiological regulation and environmental exposures. These findings indicate that hair mineral profiles may serve as non-invasive biomarkers of intergenerational elemental status, whereas dietary surveys alone may insufficiently capture long-term accumulation patterns.