Porcelli 2000.

Study characteristics
Methods	Parallel randomised controlled trial, multi‐centre
Participants	Inclusion criteria medically stable very low birth weight infants, had a gestational age 25–32 weeks, a birth weight 600–1500 g, were appropriate for gestational age, had an enteral intake of 150 mL/kg/day human milk, and were being fed human milk exclusively Exclusion criteria receiving parenteral nutrition or infant formulas significant acute or chronic illness systemic infections major congenital malformations receiving corticosteroids, diuretics or mother's milk that was < 14 days postpartum Setting: neonatal intensive care units at 8 hospitals across USA Study date: not reported
Interventions	Intervention: bovine based human milk fortifier containing 1.0 g protein added to 100 mL EBM (n = 35) Control: bovine based human milk fortifier containing 0.7 g protein added to 100 mL EBM (n = 29) Calorie content: isocaloric, 13 kcal (intervention) versus 14 kcal (control) energy added to 100 mL EBM (98 kcal vs 99 kcal in fortified EBM, 1% difference) Start of intervention: not stated other than "when human milk fortification was introduced" Mean age at trial entry: 21.2 days (SE 1.5) in intervention group and 17.7 days (SE 1.3) in control group End of intervention: when fully weaned from the assigned fortifier and receiving only unsupplemented human milk
Outcomes	Primary outcome: outcomes were not specified as primary or secondary, but study was powdered to detect difference in weight gain. Outcomes included: weight length and head circumference gain blood chemistry (vitamin D, copper, ceruloplasmin, sodium, calcium, phosphorus, blood urea nitrogen, alkaline phosphate)
Notes	Conflict of interest: not reported Source of funding: Wyeth Nutritionals International, USA supported the study.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information provided – study only described as (quote:) "… prospective, randomized controlled …"
Allocation concealment (selection bias)	Unclear risk	Insufficient information provided.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Investigators blinded to study group, carers unblinded.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Investigators blinded to study group.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Data reported in this trial were based on a per protocol analysis, only select reported safety outcomes were based on intention to treat analysis. The overall attrition rate was 28.9% (25.5% for intervention, 32.5% for control).
Selective reporting (reporting bias)	Unclear risk	Insufficient information.
Other bias	Unclear risk	Trial was sponsored by manufacturer, the role of whom was not described further.