Nepal 2003.

Study characteristics
Methods	A double‐blind, cluster‐randomised, controlled trial (factorial design) with 1 ‐ 5 treatment arms
Participants	4926 pregnant women and 4130 liveborn infants in a rural plains district of Sarlahi, community in Nepal, which had 426 sectors (communities of about 100 ‐ 150 households) ‐ only 2 of the 5 arms (total of 1659 infants) used in this review. This is the same area of Nepal in which we previously recorded evidence of vitamin A, iron, and zinc deficiency among pregnant women Women who were currently pregnant, breastfeeding a baby less than 9 months old, menopausal, sterilised or widowed were excluded. Supplementation began before conception
Interventions	The sectors were randomly assigned to 1 of 5 treatment arms The control group was vitamin A (1000 µg retinol equivalents) FA group, vitamin A + folic acid (400 µg) FAFe group, vitamin A + folic acid + iron (60 mg) FAFeZn group, vitamin A + folic acid + iron + zinc (30 mg) MN group, vitamin A + folic acid + iron+ zinc + other micronutrients (10 µg vitamin D, 10 mg vitamin E, 1.6 mg thiamine, 1.8 mg riboflavin, 20 mg niacin, 2.2 mg vitamin B‐6, 2.6 µg vitamin B‐12, 100 mg vitamin C, 65 µg vitamin K, 2.0 mg Cu, 100 mg Mg) The supplements were provided by UNICEF, identical in shape, size, and colour, arrived in Nepal in opaque, sealed, and labelled bottles coded 1 – 5. The code allocation was kept locked at the Johns Hopkins University, Baltimore. The investigators, field staff, and participants were blinded to the codes throughout the study.
Outcomes	We used the following arms for zinc versus placebo comparison (n values are live births + stillbirths). Zinc: zinc + iron + folate (n = 858). No zinc: iron + folate (n = 801) Neonatal outcomes Preterm birth Stillbirth Perinatal death Neonatal death; Birthweight Chest circumference Head circumference Length Low birthweight Small‐for‐gestational age
Notes	Adherence: mean adherence was 88%. RRs adjusted for the cluster‐design effects were presented for each of the 5 arms of the RCT Dates of study: December 1998 ‐ April 2001 Funding sources: US Agency for International Development (USAID) and additional support from the Unicef Country Office, Kathmandu, Nepal, and the Bill and Melinda Gates Foundation Declarations of interest: authors declare no conflict of interest
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomised sectors by "drawing numbered identical chips from a hat" (in blocks of 5 within each community)
Allocation concealment (selection bias)	Low risk	Supplements were of identical shape, size and colour and arrived in Nepal in opaque, sealed and labelled bottles coded 1 ‐ 5. The code allocation was kept locked at the Johns Hopkins University, Baltimore
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Participants, investigators, field staff and statisticians were all blinded to the codes throughout the study
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Investigators, field staff and statisticians were all blinded to the codes throughout the study
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	155/827 (19%) of infants in the zinc group and 167/872 (19%) in the non‐zinc group were lost to follow‐up or excluded from analysis (infant died, mother refused, home was inaccessible, birthweight was measured more than 72 hours after birth or missing data)
Selective reporting (reporting bias)	Low risk	Most expected outcomes were reported with some exceptions such as mode of birth and postpartum haemorrhage
Other bias	Low risk	No apparent evidence of other sources of bias apart from a small imbalance between groups in maternal weight (which was adjusted for in the analyses)