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

• In Event: Poster Session 04
  In Poster Session: PS 04 Topic - Language, Communication

Abstract

In 2003, Israeli infants were exposed to a defective soy-based formula lacking in thiamine, a B-vitamin necessary for deriving energy from nutrients. Among other things, these infants subsequently displayed measurable delays in language development (Fattal-Valevski, et al., 2009).

These findings have raised widespread concern, given that millions of infants, especially in regions such as Southeast Asia, currently remain at risk of thiamine deficiency (National Institute of Statistics, 2011; Whitfield, et al., 2017). We investigated the extent to which thiamine supplementation in rural Cambodian infants might protect their developmental progress in the language domain.

A double-blind randomized controlled trial provided daily thiamine supplementation (a capsule containing 0, 1.2, 2.4 or 10 mg of thiamine hydrochloride) to 248 exclusively breast-feeding Cambodian mothers when their infants were between 2 and 24 weeks of age. Infants’ language development was measured via the Mullen Scales of Early Learning (MSEL) at 2, 12, and 24 weeks. Previous research documents the MSEL as a viable assessment tool across cultures and LMICs (Jensen, et al., 2019). As well, at 24 weeks infants participated in a task assessing the magnitude of their preference for infant-directed (IDS) over adult-directed speech (ADS), both of which were instantiated in a non-native language (American English). Prior research demonstrates that an IDS preference is associated with enhanced language development (e.g., Kuhl, 2004). Moreover, discriminating IDS from ADS in a non-native language hinges on perceptual analysis of complex, novel, rapidly-unfolding auditory sequences. Thus, the IDS Preference Task assessed both the integrity of infant’s perceptual-cognitive systems for discriminating complex linguistic patterns, as well as the degree to which infants display a highly functional preference for infant-directed speech. Infants’ IDS preference was measured via looking time to a standard checkerboard stimulus, displayed on a Samsung tablet, accompanied by either IDS or ADS (stimuli adapted from ManyBabies, 2020).

We predicted a dose-response relationship between thiamine supplementation dose and infants’ MSEL receptive and expressive language scores at 24 weeks, as well as with the magnitude of infants’ IDS preference. These predictions were largely confirmed. Regression analyses showed that infants whose breast-feeding mothers received higher levels of thiamine supplementation displayed significantly higher MSEL receptive language scores (beta-weight 0.136, t = 2.36, p = 0.019) and marginally higher expressive language scores (beta-weight 0.10, t = 1.73, p < 0.084). As well, thiamine supplementation dose was significantly positively associated with a higher-magnitude preference for IDS over ADS (beta-weight 0.161, t = 2.57, p < 0.011). These patterns remained even when controlling for baseline estimates of mother’s thiamine status (via blood and breast-milk assays) prior to when supplementation began. Together, the findings point to thiamine supplementation as the source of infants’ enhanced performance on both the MSEL and IDS preference task.

These findings provide the first evidence to date that supplementing breast-feeding mothers with thiamine protects language development for infants at risk of thiamine deficiency. As well, these findings further validate the usefulness of both the MSEL and the IDS preference task for indexing clinically-relevant individual differences in infants’ language development.
 

Authors

• Anna Sanchirico, University of Oregon
  Non-Presenting Author

• DARE ANN BALDWIN, University of Oregon
  Presenting Author

• Jeffrey Measelle, University of Oregon
  Non-Presenting Author

• Kyly Whitfield, Mount Saint Vincent University
  Non-Presenting Author