Birch 1998.

Methods	Single‐centre RCT conducted in Dallas, Texas, USA
Participants	N = 79. Inclusion criteria: infants of gestational age 37 to 40 weeks, singleton births and appropriate for gestational age. Exclusion criteria: family history of milk protein allergy or genetic or familial eye disease, maternal vegetarian or vegan dietary pattern, maternal metabolic disease, anaemia or infection, congenital malformation or infection, jaundice, perinatal asphyxia, meconium aspiration syndrome, admission to NICU LCPUFA (DHA and AA) supplemented formula: N = 27 LCPUFA (DHA alone) supplemented formula: N = 26 Control formula: N = 26 Mean gestational age and birth weight: not given
Interventions	One group was fed with formula milk enriched with DHA (0.36%) and AA (0.72%). Another group was fed formula milk enriched with DHA alone (0.36%). Control group was fed standard milk formula without DHA and AA added. Infants were randomly assigned to the study formula between 1 and 5 days of life. Assigned diets were fed from within 5 days of birth until 17 weeks of age. Source of LCPUFA was single‐cell oil
Outcomes	Blood lipids were measured at 17 and 52 weeks. Growth, sweep VEP and forced preferential looking were measured at 6, 17, 26 and 52 weeks. Bayley Scales of Infant Development were measured at 18 months
Notes	Breast‐fed reference: n = 29
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Use of block randomisation schedule
Allocation concealment (selection bias)	Low risk	Use of sealed envelopes
Blinding (performance bias and detection bias) All outcomes	Low risk	Investigators conducting blood lipid analysis and visual function testing were masked to type of formula provided to infants
Incomplete outcome data (attrition bias) All outcomes	High risk	70% to 86% follow up for different outcomes
Selective reporting (reporting bias)	Low risk	All prespecified outcomes were reported
Other bias	Low risk	Appears to be free of other biases