Serum zinc response to standard therapy in acute versus persistent pediatric diarrhea: a prospective comparative...

Zinc supplementation is recommended in both acute and persistent diarrhea; however, comparative data on longitudinal biochemical response between these conditions are limited. This prospective observational study was conducted at the pediatric department of a tertiary care center in Northern India, which enrolled 72 children: 36 with acute diarrhea (group A) and 36 with persistent diarrhea (group B). All participants received oral zinc sulfate syrup providing 20 mg elemental zinc daily for 14 days. Serum zinc was measured at Day 1, 14, and 28. Longitudinal analysis was performed using a linear mixed-effects model with time and group as fixed effects and subject as a random effect. A gradual increase in serum zinc was observed in both groups. No statistically significant group-time interaction was detected, indicating similar trajectories. Zinc supplementation resulted in a modest but consistent increase in serum zinc levels in both groups. No significant difference was detected between acute and persistent diarrhea. These findings do not suggest a need for higher dosing; however, further adequately powered studies are warranted.