Thiamine supplementation benefits language development in infants at risk for thiamine deficiency

1 page.Millions of infants, especially in regions such as Southeast Asia, are currently at risk of thiamine deficiency. We investigated the extent to which maternal thiamine supplementation in rural Cambodia might protect their exclusively breast-fed infants’ language development. A double-blind randomized controlled trial provided daily thiamine supplementation (0, 1.2, 2.4, or 10mg daily) to 335 breast-feeding Cambodian mothers when their infants were between 2 and 24 weeks of age. Of the 335 infants, 248 participated in two tasks measuring language development: 1) the Mullen Scales of Early Learning (MSEL) receptive and expressive language sub-scales at 2, 12, and 24 weeks, and 2) at 24 weeks the IDS Preference Task assessing the degree to which infants display a highly functional preference for infant-directed speech (IDS) relative to adult-directed speech (ADS) at 24 weeks. We predicted a dose-response relationship at 24 weeks between maternal thiamine supplementation and both infants’ MSEL language scores and the magnitude of their IDS preference. These predictions were confirmed: infants whose mothers received higher levels of thiamine supplementation displayed a) significantly higher MSEL receptive language scores and marginally higher expressive language scores, and b) a higher-magnitude preference for IDS over ADS. These findings provide evidence that thiamine supplementation for lactating mothers benefits language development for infants at risk of thiamine deficiency