Manganese intakes in intravenously fed infants

Abstract

Manganese is recommended for inclusion in total parental nutrition (TPN) regimens, although Mn deficiency has never been documented in humans, and toxicity is well described. To determine the intravenous (iv) Mn intakes required to build up body stores in the preterm infant and achieve positive retention in full-term infants and to identify and quantify the biochemical changes that may predate frank Mn toxicity, short-term balance studies were completed in 24 preterm and full-term infants who received complete iv feeding, excluding Mn. Manganese, as MnSO₄, was then added to the iv formulations of half of the infants so that intakes were 48 μg/kg/d vs 0.8 μg/kg/d (contamination only). Positive balance was observed for the Mn-supplemented group, with 99% of the infused Mn retained. In full-term infants, intakes > 0.8 μg/kg/d were adequate to replace ongoing losses and prevent deficiency. This dosage is lower than the current recommendation of the AMA. Preterm infants receiving intakes of Mn at 9 μg/kg/d achieve in utero retention rates. Biochemical evidence of Mn toxicity was not apparent, even at the highest doses provided.