Nutrition of very low birth weight infants fed human milk with or without supplemental trace elements: a randomized controlled trial.

BACKGROUND

Very low birth weight infants (<1500 g) have high nutritional needs. Deficiencies of minerals, trace elements (especially zinc) may develop as a result of rapid growth, low body stores and low content of these substances in human milk We hypothesized that fortification of human milk might prevent deficiencies.

METHODS

Prospective, randomized trial to evaluate mineral, trace element, thyroid status and growth of infants fed human milk fortified with different amounts of calcium, phosphorus and protein, with (BMF) or without (FM 85) trace elements. Sixty-two infants, 1000 to 1499 g birth weight, were randomized. Minerals and trace elements in serum, red blood cells and human milk and alkaline phosphatase activity, TSH, T4 and FT4 in serum were measured once until the fifth day and at 3 and 6 weeks of life. Clinical course and anthropometric measurements were recorded.

RESULTS

Intake of zinc, copper, manganese, calcium, phosphorus and magnesium was higher in the BMF group (P < 0.001). Serum zinc concentrations <0.49 mg/L occurred in 12% of the FM 85 group and 7% of the BMF group at 6 weeks (not significant). Median alkaline phosphatase activity was 436/379 IU/L in the FM 85/BMF group at 6 weeks (P < 0.01). The FM 85 group showed a higher weight gain (P < 0.05), possibly because of higher caloric (P < 0.01) and protein intake (P < 0.05) at 3 weeks.

CONCLUSIONS

Zinc deficiency was rare. Elevated intake of calcium, phosphorus and zinc was associated with lower serum alkaline phosphatase activity but did not influence serum zinc concentration.