Methods	Randomized placebo controlled trial conducted in Guinea‐Bissau
Participants	Inclusion Criteria: Weight at least 2500 g at presentation and no signs of overt illness or malformations
	Exclusion Criteria: Weight <2500 g at presentation and/or signs of overt illness and/or malformations. Also, infants who died in the maternity ward before the vaccination team could arrive
	Total number randomized to the intervention group: 2145
	Total number randomized to the control group: 2200
Interventions	Intervention: 50,000 IU vitamin A intradermally
	Control: 0.5 ml vegetable oil intradermally
	Common intervention given to all groups: 10 IU vitamin E intradermally
Outcomes	Primary outcomes: Overall mortality
	Other outcomes: Bulging fontanelles, vomiting, irritability, infections, fever, skin problems, and healthcare contacts
Notes	Vitamin A supplementation appeared to benefit boys but was harmful to girls