Cox 2005.

Methods	A randomised double‐blind controlled trial.
Participants	Inclusion criteria: primigravid pregnant women; resident within the study area; in good health; less than 24 weeks pregnant. Exclusion criteria: HIV infection or tuberculosis.
Interventions	Intervention group: 48 women received weekly capsules of 10,000 IU of vitamin A as retinyl palmitate in groundnut oil, plus tocopherol as a preservative from enrolment until 6 weeks postpartum. Suplimintation was for a minimum of 18 weeks. Control group: 50 women received groundnut oil and tocopherol only in the placebo capsules from enrolment until 6 weeks postpartum.
Outcomes	Primary outcome: maternal infections (presence of placental malaria and peripheral parasitaemia). Other outcomes: Hb and birthweight.
Notes	Vitamin A levels were measured before starting supplementation. Country: Ghana. Study setting: Nkoranza District Hospital and 3 rural health clinics in Brong Ahafo region, Central Ghana.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"balanced block randomisation."
Allocation concealment (selection bias)	Unclear risk	No information provided.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Participants and personnel "double‐blind".
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information given.
Incomplete outcome data (attrition bias) All outcomes	Low risk	12 (12%) women were excluded from the analysis: 1 false pregnancy, 1 early miscarriage, 10 missed late pregnancy visit.
Selective reporting (reporting bias)	Unclear risk	The protocol of the study is not available at the moment.
Other bias	Unclear risk	The most marked difference was in educational level and gestational age at enrolment. Levels of anti‐VSACSA IgG to the FCR3CSA parasite line differed between the treatment groups at baseline. There were considerably fewer data available for the placebo than the vitamin A group at the late pregnancy follow‐up.