Background: Cystic fibrosis (CF) stands as the most common chronic multisystem and fatal inherited disease. Objectives: The present study aimed to assess the clinical presentation and laboratory findings in children with CF. Methods: This retrospective cross-sectional study reviewed the records of CF patients over a 2-year period beginning in 2018. The diagnosis of CF was confirmed based on clinical manifestations, sweat chloride tests, or genetic studies. Children aged ≥ 2 years were included; nevertheless, patients without sweat chloride tests or genetic studies were excluded. This study recorded demographic features, gastrointestinal manifestations, vitamin D levels, and the number of hospital admissions. A pediatric gastroenterologist conducted fecal elastase and stool fat analyses to evaluate pancreatic insufficiency. Vitamin D levels < 30 ng/mL were considered vitamin D insufficiency; however, levels < 20 ng/mL indicated a vitamin D deficiency. A P-value < 0.05 was considered statistically significant. Results: This study included 59 children (37 male and 22 female) in the study. Low weight, height, and body mass index (BMI) percentiles (< 5) were most frequently observed. Approximately 86.4% of the patients had consanguineous parents, and 40.7% had affected siblings. Failure to thrive (FTT) (49.2%) and recurrent respiratory infections (45.8%) were the most common clinical presentations. A majority (57.7%) of the patients were diagnosed before the age of 1 year. The mean number of admissions in the past 2 years was 3, and 58% of the cases reported gastrointestinal symptoms. A significant correlation was observed between vitamin D levels and the number of hospital admissions (Pearson coefficient = 0.298, P = 0.042). Conclusions: In this study, there was a high prevalence of vitamin D insufficiency and FTT in children with CF. Additionally, there was a significant correlation between vitamin D levels and the number of hospital admissions over a 2-year period.
