Baseline characteristics of infants and mothers.

<p>*Defined as birth weight <2500 g.</p><p>**Detailed feeding information was collected from mothers at 6 weeks, 3 months and 6 months of age, including whether any of 22 liquids (water, juice, tea, cooking oil), milks (formula, fresh, tinned), medicines (traditional, oral rehydration solution, prescribed) or solid foods (porridge, sadza, fruit, vegetables, meat, eggs) had been given to the infant. Breastfeeding was defined as exclusive, predominant or mixed at 3 months of age, according to previously published definitions <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0086928#pone.0086928-Iliff1" target="_blank">[19]</a>. Data were not available at 3 months of age for 6 stunted and 25 non-stunted infants.</p>†<p>In the ZVITAMBO trial, mother-infant pairs were randomized within 96 h of birth to one of 4 treatment groups (Aa, Ap, Pa, Pp), where ‘A’ was maternal vitamin A supplementation (400,000 IU), ‘P’ was maternal placebo, ‘a’ was infant vitamin A supplementation (50,000 IU) and ‘p’ was infant placebo. Full details of the trial have been published elsewhere <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0086928#pone.0086928-Humphrey2" target="_blank">[18]</a>.</p>‡<p>Maternal weight and BMI were measured 6 weeks postpartum.</p><p>WAZ: weight-for-age Z-score; HAZ: height-for-age Z-score; WHZ: weight-for-height Z-score; SD: standard deviation; IQR: interquartile range.