Vitamin D Deficiency and Its Hematological Correlates in Patients with Sickle Cell Disease at a Ugandan Clinic.

Purpose: To determine the prevalence of vitamin D deficiency (VDD), evaluate its correlation with key hematological parameters, and identify associated factors among patients attending the Sickle Cell Clinic at Mengo Hospital (Kampala, Uganda). Patients and Methods: This cross-sectional study enrolled 213 patients with sickle cell disease (SCD) at Mengo Hospital, serum 25-hydroxyvitamin D levels were measured. Levels were classified as deficient (<20 ng/mL) or sufficient (≥20 ng/mL). Hematological indices, red blood cell (RBC) count, hemoglobin (Hb), and red cell distribution width-coefficient of variation (RDW-CV) were assessed using an automated analyzer, and Spearman correlation was used to assess correlations with vitamin D levels. Multivariable Poisson regression identified variables associated with vitamin D deficiency (VDD), reporting outcomes as adjusted prevalence ratios (aPR). Results: The median age was 10 years (IQR 5-13); 50.7% were male. The prevalence of vitamin D deficiency (VDD) was 47.4% (95% CI 40.8-54.2%). Weak but significant positive correlations were observed between serum vitamin D levels and RBC count ( Conclusion: Nearly half of the patients with sickle cell disease had vitamin D deficiency. Older age increased the risk. VDD is weakly but significantly associated with lower Hb/RBC and higher RDW, suggesting a possible contributory role in the hematologic profile of Ugandan SCD patients.