Background/Objective: Seasonal upper respiratory tract infections (URTIs) are common in children and contribute to absenteeism and reduced quality of life. Over-the-counter treatments show limited efficacy and may cause adverse effects, thus warranting the need for natural alternatives. This study evaluated the efficacy of a whole-fruit supplement derived from boysenberry and apple (BerriQi) in reducing symptom severity and duration in school-aged children with URTIs using the Wisconsin Upper Respiratory Symptoms Survey for Kids (WURSS - K). Methods: In this double-blind, randomised, placebo-controlled study, 84 children aged 5 -13 years with URTI-associated school absence were assigned to receive BerriQi or placebo (two chewable tablets daily) for 14 days. Outcomes included the severity and duration of global illness, composite symptom and function scores. Results: Both groups showed progressive reductions in global illness severity, symptom, and function score over 14 days. However, the BerriQi group consistently reported lower scores across all outcomes. While global illness severity did not differ significantly between groups, total symptom severity was significantly reduced with BerriQi (P=0.04), and functional scores showed a trend toward improvement (P=0.05). The BerriQi group experienced fewer sick days compared with placebo (8 vs. 11 days) and demonstrated a higher likelihood of functional recovery (HR = 1.79, 95% CI: 1.09 - 2.91; P=0.02). Conclusions: These findings suggest that BerriQi may serve as a promising natural paediatric supplement for alleviating respiratory illness symptoms and supporting faster functional recovery, potentially reducing school absenteeism associated with upper respiratory tract infections (URTIs).