Association between serum vitamin D and sex hormones in women: a cross-sectional analysis using NHANES Data...

Most studies on the impact of vitamin D on sex hormones focus on specific populations, such as older males, Asian males, or those with certain health conditions. Limited evidence exists on the relationship between vitamin D and sex hormones in American women. This cross-sectional analysis used National Health and Nutrition Examination Survey (NHANES) data to explore the association between serum vitamin D levels and sex hormones levels in women. Data from NHANES (2021-2023) were analyzed. Participants were categorized by serum vitamin D levels: Deficient (<50 nmol/L), Insufficient (50-74.99 nmol/L), and Adequate ( ≥ 75 nmol/L). One-way ANOVA and Chi-square tests were used for comparisons, and linear regression evaluated associations. Our analysis specifically focused on a subset of 3181 women aged 18 years and older (18-80 years). Women in the adequate vitamin D group had lower body mass index (BMI) (29.16 vs. 32.10 kg/m², p < 0.001), lower total testosterone (24.10 vs. 32.28 ng/dL, p < 0.001), progesterone (139.05 vs. 229.73 ng/dL, p < 0.001), estrone sulfate (687.10 vs. 1023.08 pg/mL, p < 0.001), and dehydroepiandrosterone sulfate (DHEAS) (66.41 vs. 100.56 µg/dL, p < 0.001) compared to the deficient vitamin D group. They also had higher sex hormone-binding globulin (SHBG) (70.37 vs. 58.55 nmol/L, p < 0.001), follicle-stimulating hormone (FSH) (50.30 vs. 23.99 mIU/mL, p < 0.001), and luteinizing hormone (LH) (26.39 vs. 16.64 mIU/mL, p < 0.001) compared to the deficient vitamin D group. Linear regression revealed that higher serum vitamin D was inversely associated with 17α-hydroxyprogesterone (Beta = -0.85, P = 0.023), androstenedione (Beta = -0.181, p < 0.001), anti-Müllerian hormone (Beta = -0.238, p < 0.001), DHEAS (Beta = -0.204, p < 0.001), total testosterone (Beta = -0.080, P = 0.042), while showing a positive association with follicle-stimulating hormone (Beta = 0.260, p < 0.001) and luteinizing hormone (Beta = 0.208, p < 0.001). Serum vitamin D levels were negatively associated with testosterone and estradiol in American women, particularly in older individuals.