Correlation of Vitamin D Deficiency with Levothyroxine Requirements Among Hypothyroid Patients in Albayda, Libya

Abstract

Hypothyroidism is a widespread endocrine disorder resulting from inadequate thyroid hormone synthesis and is frequently associated with low vitamin D (VitD) levels. Current research has highlighted that VitD may affect thyroid function and levothyroxine treatment response; however, limited data are available for the Libyan population. The current study was designed to determine the correlation between serum VitD concentrations and levothyroxine dosage among hypothyroid patients. A comparative cross-sectional research study was performed in a cohort of one hundred (100) hypothyroid patients receiving levothyroxine at the General Internal Medicine Department, Albayda Medical Center, Albayda, Libya. Demographic and clinical profiles, along with blood samples, were collected from all participants to evaluate serum VitD and thyroid-stimulating hormone (TSH) levels using standard laboratory procedures. Levothyroxine doses were obtained from patients’ medical records. Statistical analyses were conducted to examine the correlations among serum VitD levels, levothyroxine dosage, and TSH levels. The results showed a high prevalence of VitD deficiency among hypothyroid individuals. Serum VitD levels were negatively correlated with levothyroxine dosage (r=-0.39, p= 0.006), indicating that patients with lower VitD levels may require higher levothyroxine doses. In addition, lower serum VitD levels were correlated with higher TSH levels (r =-0.34, p=0.003). In conclusion, these results suggest that VitD deficiency is linked to poor thyroid function control and higher levothyroxine dose requirements in hypothyroid patients. Routine assessment of VitD may improve disease management and therapeutic outcomes in this population.