Nairobi slums face significant nutritional deficiencies that may affect children's school performance. A randomized controlled trial was conducted, with 200 participants randomly assigned to either the intervention group (receiving tailored nutritional supplements) or control group (standard educational resources). Children who received the nutritional intervention showed a statistically significant improvement in standardised test scores by an average of 15% compared to controls. The trial demonstrates that targeted nutritional support can positively impact academic performance among children living in Nairobi slums. Public health initiatives should consider implementing and evaluating similar interventions in other urban slum areas globally. Nutritional Interventions, School Performance, Nairobi Slums, Randomized Controlled Trial Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.