Objective: We aimed at the frequency determination of deficiency of Vitamin “D” in children diagnosed with rickets. Methods: Our descriptive case series research was carried out on five years of children in the duration of six months at Services Hospital, Lahore (Pediatrics Department) from November, 2016 to May, 2017. All the children who were diagnosed with rickets were included in this research but Vit-D intake cases were not included. Informed consent and ethical approval were met as necessary formalities. Every child was screened for blood sugar to validate the level of Vit-D (25 [OH] D). We labelled the vitamin “D” serum level which was under (20 ng/ml) as (25 [OH] D) rickets deficiency. Pre-designed form was used for the collection of information and outcomes were analyzed on SPSS software. Results: Mean age factor of the research participants was (1.5 ± 1) year. In the total 159 cases male to female proportion was as 91 male children (57.2%) and 68 female children (42.8%). Sun exposure frequency was reported as two to three days in a week in 97 children (61.01%); whereas, Vit-D fortified diet was taken by 34 children (21.38%). Vit-D deficiency was reported in 120 children (75.47%). Conclusion: Seventy-five percent Vit-D deficiency was found in the children who were in the age bracket of six-months to five-years. Keywords: Vitamin D (Vit-D), Rickets, Deficiency, Children, Sun Exposure, 25-hydroxy Vit-D (25 [OH] D) and Serum.