Thiamine concentration in human milk is correlated with maternal and infant thiamine status: A cross-sectional analysis of the Lao Thiamine Study

Authors: HESS, SONJA - University Of California, Davis; ARNOLD, CHARLES - University Of California, Davis; SMITH, TARYN - University Of Liverpool; Allen, Lindsay; HAMPEL, DANIELA - University Of California, Davis; JONES, KERRY - University Of Cambridge; PARKINGTON, DAMON - University Of Cambridge; MEADOWS, SARAH - University Of Cambridge; SITTHIDETH, DALAPHONE - Lao Tropical And Public Health Institute(LAO TPHI); KOUNNAVONG, SENGCHANH - Lao Tropical And Public Health Institute(LAO TPHI)

Submitted to: Maternal and Child Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/5/2025
Publication Date: 4/10/2025
Citation: Hess, S.Y., Arnold, C.D., Smith, T.J., Allen, L.H., Hampel, D., Jones, K.S., Parkington, D.A., Meadows, S.R., Sitthideth, D., Kounnavong, S. 2025. Thiamine concentration in human milk is correlated with maternal and infant thiamine status: A cross-sectional analysis of the Lao Thiamine Study. Maternal and Child Nutrition. 21(3). Article e70027. https://doi.org/10.1111/mcn.70027.
DOI: https://doi.org/10.1111/mcn.70027

Interpretive Summary: The vitamin and mineral content of human milk depends on the mother's status, and if she is deficient her infant consequently is also at risk of deficiency. Thiamine deficiency remains of great concern among infants in Asia and poor maternal status reduces the concentrations in breast milk. Our aims were to investigate relationships between indicators of maternal thiamine status (thiamine diphosphate [ThDP] or erythrocyte transketolase activation coefficient [ETKac]) and human milk thiamine concentrations (MTh), and between MTh and infant status (ThDP or ETKac) among breastfed infants <6 months of age in northern Lao PDR. Hospitalized infants and young children (aged 21 days – <18 months) with respiratory, cardiac and/or neurological symptoms that point towards thiamine deficiency were eligible. Children in a community comparison group were matched by age, sex and residence with the symptomatic group. Venous whole blood ThDP and MTh were measured using high pressure liquid chromatography, and ETKac was analyzed in washed erythrocytes by UV spectrophotometry. For this secondary analysis, relationships between biomarkers were assessed in breastfed infants aged <6 months. We found, when all women combined, a ThDP <95 nmol/L inr 78.5%, and elevated ETKac (>1.25) in 52.6%. Low MTh (<90 µg/L) was observed for 45.4% of the samples. Maternal ThDP was moderately associated with milk thiamine, while ETKac was strongly correlated with milk thiamine ('=-0.71). For all infants combined, the prevalence of ThDP <95 nmol/L was 79.2% and elevated ETKac (>1.25) 50.2%. MTh was moderately correlated with infant status - ThDP concentration ('=0.39) and ETKac ('=-0.52). Thus, low thiamine status was found among women and their breastfed infants in northern Lao PDR and needs to be addressed, e.g. by offering maternal thiamine supplementation, ideally as part of a multiple micronutrient supplement, and/or increasing dietary diversity.

Technical Abstract: Background: The breast milk content of some micronutrients including thiamine depends on maternal micronutrient status, and if low, breastfed infants are at risk of deficiency. Thiamine deficiency remains an important cause of morbidity and mortality among infants in Asia. Objective: To explore correlations between maternal thiamine diphosphate (ThDP) or erythrocyte transketolase activation coefficient (ETKac) and human milk thiamine concentration (MTh) and between MTh and infant ThDP or ETKac among breastfed infants <6 months of age in northern Lao PDR. Methods: Hospitalized infants and young children (aged 21 days – <18 months) with respiratory, cardiac and/or neurological symptoms suggestive of thiamine deficiency were eligible. Children in a community comparison group were matched by age, sex and residence. Venous whole blood ThDP and MTh were determined by HPLC-FLD, and ETKac in washed erythrocytes by UV spectrophotometry. Associations between biomarkers were assessed using Spearman correlations and linear regression. This secondary analysis was limited to breastfed infants aged <6 months. Results: Mean age of women (n=510) was 24.5±6.5 years and infants (n=477) 2.7±1.4 months. Among all women combined, the prevalence of ThDP <95 nmol/L was 78.5%, elevated ETKac (>1.25) 52.6%, and low MTh (<90 µg/L) 45.4%. Maternal ThDP was moderately correlated with MTh (Spearman correlation coefficient '=0.50) and ETKac was strongly correlated with MTh ('=-0.71). Among all infants combined, the prevalence of ThDP <95 nmol/L was 79.2% and elevated ETKac (>1.25) 50.2%. MTh was moderately correlated with infant ThDP concentration ('=0.39) and with infant ETKac ('=-0.52). Conclusions: Low thiamine status was prevalent among women and their breastfed infants in northern Lao PDR. Maternal thiamine supplementation, ideally as part of a multiple micronutrient supplement, and/or increasing dietary diversity is urgently needed to improve thiamine status among women and their infants.