Background Extremely preterm infants have high nutrient requirements due to limited stores of nutrients and rapid postnatal growth. However, many infants experience suboptimal growth. It is still unclear to what extent micronutrient intakes affect growth during early postnatal life in these infants.
Aim To describe micronutrient intakes and explore possible associations with 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+2 days and a mean birth weight of 765 g. Intakes of calcium, phosphorus magnesium, zinc, copper, iodine, vitamin D and folate were lower than estimated requirements while intakes of iron, vitamin K and several water-soluble vitamins were higher than estimated requirements. High iron intakes were explained by blood transfusions. Taking macronutrient intakes and severity of illness into account, folate intakes were positively correlated with weight (p = 0.001) and length gain (p = 0.003) and iron intake was negatively associated with length gain (p = 0.006) during the first 70 days of life.
Conclusions Intakes of many micronutrients were insufficient. Even when considering macronutrient intakes and severity of illness, several micronutrients were independent predictors of early growth. Low intakes of folate were associated with poor weight and length gain and high iron intakes were associated with poor length and head circumference growth. Optimised early micronutrient intakes may improve early growth in extremely preterm infants.