Hypovitaminosis D is associated with a variety of health conditions. Understanding the effects of low vitamin D levels on children and adolescents with sickle cell disease (SCD) remain limited. The project’s aim was to determine hypovitaminosis D prevalence in children and adolescents with SCD and explore correlates to improve current screening and treatment strategies. A retrospective, electronic health record (EHR) review was conducted on 104 children and adolescents with SCD who attended a non-profit tertiary children’s hospital in southwestern Pennsylvania. A descriptive, cross-sectional, correlational design was used to examine hypovitaminosis D prevalence and correlate vitamin D levels with comorbidities, medications, biological and environmental factors in this sample. Results demonstrated the hypovitaminosis D prevalence rate was 88.5% (< 30 ng/mL); deficiency occurred among 39% (< 20 ng/mL); subjects were 6.9 times as likely to have lower vitamin D levels in fall versus summer (p = 0.0007). Underweight subjects were 6.2 times (p = 0.0056) as likely to have lower vitamin D levels compared to healthy weight subjects. Sufficient vitamin D levels only occurred among subjects < 10. Higher probability of hypovitaminosis D was noted in subjects reporting liking milk “sometimes” versus “yes” (p = 0.0001). Hospitalizations for acute chest syndrome (ACS) had an association with vitamin D severity (p = 0.0497). The conclusion is hypovitaminosis D is prevalent among children and adolescents with SCD living in southwestern Pennsylvania. To promote future positive patient outcomes, continued identification of correlates associated with hypovitaminosis D will assist in developing well-designed prevention and treatment programs.