Maternal and Infant Determinants of Zinc Status and Zinc's Association with Anthropometry in 3-Month-Old Bangladeshi Infants.

BACKGROUND/OBJECTIVES: Zinc deficiency remains a public health concern in South Asia but is rarely studied through gestation to infancy. METHODS: We identified maternal and infant factors related to plasma zinc of 3 mo old Bangladeshi infants (n = 317) in the context of a trial of a daily antenatal to 3 mo postpartum multiple micronutrient supplementation (MMS) with 15 vitamins and minerals, including 12 mg zinc, versus iron-folic acid (IFA). Factors explored included maternal age, parity, and plasma zinc in early (pre-supplementation) and late pregnancy, at 3 months postpartum, and in milk; cord blood zinc (n = 83); birth outcomes; and infant feeding and biomarkers. Consequently, infant zinc was explored with 3 mo anthropometry and growth rates. RESULTS: Mean ± SD infant plasma zinc was 15.63 ± 6.65 µmol/L, with 10.1% deficiency (<9.9 µmol/L). In adjusted analyses, infant zinc was positively associated with maternal age [20-30 years +0.11 µmol/L (p = 0.018) and ≥30 years +0.28 µmol/L (p = 0.003) relative to <20 years], maternal early pregnancy zinc (+0.01 µmol/L per 1 µmol/L maternal zinc, p = 0.011), and infant ferritin (+0.001 µmol/L per 1 µg/L, p = 0.007); conversely, infant zinc was -0.13 µmol/L lower (p = 0.013) with maternal parity ≥2 versus 0-1 and with partial versus exclusive breastfeeding (-0.15 µmol/L, p = 0.038). Relationships with MMS, maternal later pregnancy, postpartum, milk, and cord blood zinc were absent. Length-for-age (+0.02 per µmol/L, p = 0.047) but not weight-for-length Z-scores at 3 months were associated with infant zinc. CONCLUSIONS: Thus, infant zinc was associated with pre- but not post-MMS maternal zinc, age and parity, feeding style, and infant iron status. Infant length but not weight was associated with plasma zinc.