BMC pediatrics

Motor development related to duration of exclusive breastfeeding, B vitamin status and B12 supplementation in infants with a birth weight between 2000-3000xa0g, results from a randomized intervention trial.

PMID 26678525


Exclusive breastfeeding for 6xa0months is assumed to ensure adequate micronutrients for term infants. Our objective was to investigate the effects of prolonged breastfeeding on B vitamin status and neurodevelopment in 80 infants with subnormal birth weights (2000-3000 g) and examine if cobalamin supplementation may benefit motor function in infants who developed biochemical signs of impaired cobalamin function (total homocysteine (tHcy) > 6.5xa0μmol/L) at 6xa0months. Levels of cobalamin, folate, riboflavin and pyridoxal 5´-phosphate, and the metabolic markers tHcy and methylmalonic acid (MMA), were determined at 6xa0weeks, 4 and 6xa0months (n = 80/68/66). Neurodevelopment was assessed with the Alberta Infants Motor Scale (AIMS) and the parental questionnaire Ages and Stages (ASQ) at 6xa0months. At 6xa0months, 32 of 36 infants with tHcy > 6.5xa0μmol/L were enrolled in a double blind randomized controlled trial to receive 400xa0μg hydroxycobalamin intramuscularly (n = 16) or sham injection (n = 16). Biochemical status and neurodevelopment were evaluated after one month. Except for folate, infants who were exclusively breastfed for >1xa0month had lower B vitamin levels at all assessments and higher tHcy and MMA levels at 4 and 6xa0months. At 6xa0months, these infants had lower AIMS scores (p = 0.03) and ASQ gross motor scores (p = 0.01). Compared to the placebo group, cobalamin treatment resulted in a decrease in plasma tHcy (p < 0.001) and MMA (p = 0.001) levels and a larger increase in AIMS (p = 0.02) and ASQ gross motor scores (p = 0.03). The findings suggest that prolonged exclusive breastfeeding may not provide sufficient B vitamins for small infants, and that this may have a negative effect on early gross motor development. In infants with mild cobalamin deficiency at 6xa0months, cobalamin treatment significantly improvement cobalamin status and motor function, suggesting that the observed impairment in motor function associated with long-term exclusive breastfeeding, may be due to cobalamin deficiency., number NCT01201005.