SELENIUM STATUS OF NEW-ZEALAND INFANTS FED EITHER A SELENIUM SUPPLEMENTED OR A STANDARD FORMULA

Objective: New Zealand soils are deficient in the essential micronutrient, selenium. New Zealand infants have low selenium levels at birth and experience a further decline if fed cows milk based formula. This study examined the selenium status of infants fed with a new commercially available selenium supplemented formula. Methodology: Forty-four newborn infants, whose mothers wished to formula feed, were randomized in an open controlled trial to be fed a commercially available selenium supplemented cows milk formula (containing 17 mu g Se/L) or an unsupplemented formula (containing 4.6 mu g Se/L). Cord, 1 and 3 month blood samples were obtained for selenium status (plasma and red cell selenium and glutathione peroxidase) and thyroid function. Results: Mean plasma selenium and glutathione peroxidase values were significantly higher in supplemented than unsupplemented infants at 1 month (unpaired t-tests; P<0.0001 and P=0.001 respectively) and 3 months (P<0.0001 and P=0.0005). Analysis within treatment groups between time points (paired t-tests) showed that selenium supplementation prevented the fall in plasma selenium from birth to 1 month seen in unsupplemented infants and was associated with a rise in levels between 1 and 3 months (P=0.002). Conclusions: Supplementing cows milk formula with selenium to replicate the levels found in breast milk is nutritionally sound. Feeding from a few days of age with a formula containing 17 mu g Se/L in infants with low selenium status at birth is sufficient to cause a rise to 80% of adult levels at 3 months of age.