Vitamin B-6 content of breast milk and neonatal behavioral functioning

Objective To determine if vitamin B-6 intakes of mothers influence the B-6 vitamer content of transition milk and if correlations exist between the vitamin B-6 content of the milk and the infants' neurobehavioral functioning. Design Transition milk samples were collected from mothers 8 to 11 days after delivery for B-6 vitamer analysis. Neurobehavioral functioning of the neonates was determined at that time. A 24-hour recall was used in estimating vitamin B-6 intakes of the mothers. Subjects A convenience sample of low-income, lactating women (n=25) who had normal pregnancies. Main outcome measures B-6 vitamers were measured in the mothers' transition milk samples. Neurobehavioral functioning was assessed using the Brazelton Neonatal Behavioral Assessment Scale (NBAS), and the Center for Epidemiologic Studies Depression Scale was used to evaluate maternal depression. Statistical analyses performed Pearson correlation coefficients were used to assess if statistically significant relationships existed between variables. The Mann-Whitney test was used to determine if median group values were significantly different. Results The major B-6 vitamer in transition milk was pyridoxal. Mothers with vitamin B-6 intake greater than the median value had a significantly higher median pyridoxal level in their breast milk than did the mothers with intakes below the median value. All except one mother had a dietary vitamin B-6 intake that exceeded the Recommended Dietary Allowance. Infant scores on habituation (r=.94, P<.05) and autonomic stability (r=.34, P<.05) subscales of the NBAS were positively correlated with milk pyridoxal values. Applications/conclusions Vitamin B-6 is important for normal behavioral functioning of infants. The mothers' vitamin B-6 intake affects vitamin B-6 levels of breast milk and the need for consuming recommended levels of vitamin B-6 should be emphasized to all pregnant and lactating mothers.