Intakes of Micronutrients Are Associated With Early Growth in Extremely Preterm Infants

Objectives: The aim of the study was to describe micronutrient intakes and explore possible correlations to growth during the first 70 days of life in extremely preterm infants. Methods: Retrospective population-based study including extremely preterm infants (<27 weeks) born in Sweden during 2004-2007. Detailed nutritional and growth data were derived from hospital records. Results: Included infants (n = 531) had a mean gestational age of 25 weeks and 2 days and a mean birth weight of 765 g. Estimated and adjusted intakes of calcium, phosphorus magnesium, zinc, copper, selenium, vitamin D, and folate were lower than estimated requirements, whereas intakes of iron, vitamin K, and several water-soluble vitamins were higher than estimated requirements. High iron intakes were explained by blood transfusions. During the first 70 days of life, taking macronutrient intakes and severity of illness into account, folate intakes were positively associated with weight (P = 0.001) and length gain (P = 0.003) and iron intake was negatively associated with length gain (P = 0.006). Conclusions: Intakes of several micronutrients were inconsistent with recommendations. Even when considering macronutrient intakes and severity of illness, several micronutrients were independent predictors of early growth. Low intake of folate was associated with poor weight and length gain. Furthermore, high iron supply was associated with poor growth in length and head circumference. Optimized early micronutrient supply may improve early growth in extremely preterm infants.