Thiamine Concentration in Human Milk Is Correlated With Maternal and Infant Thiamine Status: A Cross-Sectional Analysis of the Lao Thiamine Study.

The human milk content of some micronutrients including thiamine depends on maternal 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. We aimed 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. Hospitalized infants (aged ≥ 21 days) with symptoms suggestive of thiamine deficiency were eligible. Infants 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's ρ correlations and linear regression. Among all women combined (n = 489), 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 (ρ = 0.50) and ETKac was strongly correlated with MTh (ρ = -0.71). Among all infants combined (n = 359), 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 (ρ = 0.39) and with infant ETKac (ρ = -0.52). Maternal thiamine status predicts the thiamine concentration in human milk, and thiamine status of breastfed infants < 6 months of age depends on the thiamine provided through this milk. Effective interventions are needed to improve maternal and infant thiamine status and wellbeing. TRIAL REGISTRATION: Clinicaltrials.gov NCT03626337.