Key Message
Prolactin secretion is influenced by factors related to the mother, infant, and environment, and this study was to investigate the correlations among maternal and infant factors, lead exposure, and serum prolactin levels during lactation. In total 110 exclusively lactating mothers were included, with information on their socio-demographic, daily diet, blood lead level, prolactin level, and infant characteristics. Breastfeeding frequency had a stronger positive relationship with serum prolactin levels than protein and calcium intake. However, lead exposure was associated with reduced serum prolactin levels during lactation. Consequently, specific interventions from policymakers are necessary to manage breastfeeding in mothers exposed to lead.