ABSTRACT   Malnutrition contributes directly or indirectly to more than 60% of 10 million child deaths each year. Vitamin D deficiency is a worldwide phenomenon. Therefore the study aims to explore gender and age-wise deficiency of vitamin D in school-aged children of the local area of District Mardan. A total of 400 children between the ages of 4-15 years were studied. A systematic random sampling technique was applied for sample collection. In the current research work, 400 samples were estimated for the exploration of vitamin D deficiency in school-aged children. A high percentage of Vitamin D deficiency was found in males 45(22.5%) while a very low ratio was found in females 25(12.5%). The ratios of insufficiency in the school-aged children were also high in male 55(27.5%) children as compared to female 25(12.5%) students were respectively. Aged-wise exploration of vitamin D deficiency shows that very low frequency was showed in low aged group 4-7 years(20) 10%, similarly in 8-11 years the frequency of vitamin D deficiency was 30(15%) while in the aged group 12-15 years the frequency of Vitamin D deficiency were found very high 40(20%). Residency-wise results show that the frequency ratio of urban children was high 40(20%) as compared to rural area children 30(15%) respectively. This emerging health problem of Vitamin D deficiency and its connection with the academic career of school-going children has long-term health impacts. The present study highlighted the association between vitamin D deficiency in different age groups, genders, and socioeconomic status-wise exploration of vitamin D deficiency.