Table 4. Mean changes within each study group between baseline and week 22 with estimates of intervention effect for serum ferritin, plasma zinc, and plasma retinol, by anthropometric status or sex 1 . 1 All estimates are from linear mixed models including group (intervention/placebo) and anthropometric status (undernourished/normal weight/overweight-obese) or sex (girl/boy), and their interaction (group × anthropometric status; or group × sex) as fixed effects, and school as a random effect. The model for plasma zinc used values adjusted for time of day of blood sampling 42 , and all models used values corrected for inflammation 40,41 . 2 Values for serum ferritin and plasma zinc are the mean change (95% CI) within each group between baseline and week 22. Positive values indicate within-group increases. Values for plasma retinol are a ratio of geometric means (95% CI) for baseline and week 22—all ratios are above 1 and indicate within-group increases. 3 The intervention effect for serum ferritin and plasma zinc is the difference in the mean change from baseline to week 22 between the intervention group and the placebo group (Sidak-adjusted 95% CI)—all values are positive and indicate greater positive changes in the intervention group. The intervention effect for plasma retinol is expressed as a ratio of ratios (Sidak-adjusted 95% CI)—all values are above 1 and indicate positive changes in the intervention group. 4 Undernourished defined as either underweight, stunting, or wasting. Underweight defined as weight-for-age z score < − 2; stunting as height-for-age z score < − 2; and wasting as BMI-for-age z score < − 2. Normal weight defined as BMI-for-age z score ≥ − 2 and BMI-for-age z score ≤ 1 in the absence of undernutrition. Overweight/obesity defined as BMI-for-age z score > 1 in the absence of undernutrition 32