Thiamine deficiency--a neglected problem of infants and mothers--possible relationships to sudden infant death syndrome.

An unexpectedly high incidence of biochemical thiamine deficiency (erythrocyte transketolase) was found in groups of mothers and infants, selected for apparent health from a westernized Caucasian community in Australia. Deficiency was common in mothers at term but not their infants, and in apparently healthy older infants but not their mothers. These findings can be explained by preferential delivery of thiamine to the fetus, at the expense of the pregnant mother; after delivery the mother recovers, and the infant becomes depleted. The incidence of thiamine deficiency was high in 'near-miss' sudden infant death syndrome (SIDS) infants and their mothers, and in siblings of SIDS. The thiamine deficient infants had a high familial incidence of SIDS deaths. These 'high risk families' might reflect poor nutrition or genetic defects of thiamine uptake and metabolism. Since apparently thriving infants with thiamine deficiency can sometimes die unexpectedly, thiamine status deserves more attention in clinical practice and research.