Background: Despite their increasing importance in children's nutrition, studies on selenium levels in neonates in Spain are scarce and often contradictory.
Objectives: To establish the standard serum levels of selenium in healthy full term neonates in our area and to contribute knowledge of the perinatal factors that influence these levels.
Methods: We determined selenium levels in serum by atomic absorption spectrophotometry in 247 neonates: 70 healthy full term neonates, 60 sick full term neonates, 18 neonates with intrauterine growth retardation (> 37 weeks; birthweight < 2500 g), 44 healthy preterm neonates and 55 sick preterm neonates.
Results: Healthy full term newborns showed higher serum selenium levels than healthy preterm neonates (35.11 6.94 g/l, range: 18.4-48 g/l versus 28.65 5.95 g/l, range: 15-44.4 g/l, p < 0.001). In the group with intrauterine growth retardation, serum selenium levels were higher than in the healthy preterm group (30.80 6.97 g/l, range: 20-45.6 g/l versus 28.65 5.95 g /L, range: 15-44.4 g/l) but lower than in the full term and normal birthweight group (idem versus 35.11 6.94 g/l, range 18.4-48 g/l). Likewise, the low birthweight group (< 2500 g) showed lower mean serum selenium levels than the normal birthweight group (27.98 6.75 g/l, range 15-48 g/l versus 33.09 7.52 g/l, range 14.4-48 g/l; p < 0.001).
Conclusions: Prematurity and low birthweight are the best predictors for risk of neonatal hyposeleniemia.