Comparative Analysis of Thyroid Hormone Profiles and Vitamin D Status between Males and Females in Al-Bayda City, Libya: A Cross-Sectional Biochemical Study

Abstract

Thyroid hormones and vitamin D play essential roles in regulating metabolism, growth, and overall health. Alterations in their concentrations may contribute to various endocrine and metabolic disorders. This study aimed to evaluate thyroid hormone profiles and vitamin D status among adults in Al-Bayda City and to investigate potential gender-related differences. A cross-sectional study was conducted on 40 adult participants (20 females and 20 males) from Al-Bayda City, Libya. Serum levels of triiodothyronine (T₃), thyroxine (T₄), thyroid-stimulating hormone (TSH), and vitamin D were measured. Descriptive statistics, Shapiro–Wilk normality tests, independent samples t-tests, and one-sample t-tests were performed using Minitab version 17. Statistical significance was considered at p < 0.05. The overall mean values of T₄, T₃, TSH, and vitamin D were 8.04 ± 1.55 µg/dL, 1.41 ± 0.15, 1.69 ± 1.18, and 20.75 ± 11.58 ng/mL, respectively. Females exhibited significantly higher T₄ levels than males (8.53 ± 1.70 vs. 7.56 ± 1.25; p = 0.047), whereas males showed significantly higher vitamin D levels than females (24.44 ± 10.87 vs. 17.07 ± 11.34 ng/mL; p = 0.043). No significant gender differences were observed for T₃ (p = 0.500), TSH (p = 0.979), or age (p = 0.221). Normality testing revealed that T₄, T₃, and age were normally distributed, while TSH and vitamin D showed non-normal distributions. Comparison with reference values indicated that vitamin D levels were significantly lower than the recommended reference level of 30 ng/mL (p < 0.001), whereas T₃, T₄, and TSH remained within normal ranges. The study demonstrated significant gender-related differences in T₄ and vitamin D concentrations among adults in Al-Bayda City. Furthermore, vitamin D levels were markedly below the recommended reference value, suggesting a high prevalence of vitamin D insufficiency in the studied population. Regular screening and appropriate vitamin D supplementation strategies may be beneficial for improving public health outcomes