Prevalence and Associated Factors of Vitamin D Deficiency in High Altitude Region in Saudi Arabia: Three-Year Retrospective Study.

Background: Vitamin D has many functions in the human body, and its deficiency is associated with skeletal and non-skeletal diseases. Vitamin D deficiency (blood level of 25 (OH) vitamin D < 20 ng/mL) has been reported worldwide, including Kingdom of Saudi Arabia (KSA). Its prevalence and associated factors vary according to KSA region. Therefore, this study aimed to explore the prevalence and risk factors of vitamin D deficiency in the Taif region of KSA. Methods: This retrospective study included patients who attended outpatient clinics at the Alameen General Hospital from 2019 to 2021. Demographic, clinical, and laboratory data were collected using a hospital software system. Results: The study included 2153 patients and vitamin D deficiency was diagnosed in 900 (41.8%) of whom were diagnosed with vitamin D deficiency. It was more common in males (P=0.021), younger age (<0.001), and in patients without comorbidities. There was a positive correlation between 25 (OH) vitamin D levels and blood cholesterol, high-density lipoprotein, calcium, and vitamin B12 levels. In the binary logistic regression analysis, age was the most significant predictor (P<0.001), followed by the absence of thyroid disease (P=0.012) and asthma (P=0.030). Conclusion: Vitamin D deficiency is common in the Saudi population despite sunny weather in KSA. It is more prevalent among males, younger individuals, and those without comorbidities such as thyroid diseases and asthma.