Association between serum vitamins and sex hormone levels in adolescent males: based on the National Health and Nutrition Examination Survey (NHANES).

Abstract

Background: The association between serum vitamins and sex hormones has gained considerable research interest; however, studies focusing specifically on adolescent males remain limited.

Objective: To analyze associations between key serum vitamins and sex hormone levels in adolescent males.

Methods: This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) (2001-2004). Weighted generalized linear regression models were employed to examine associations between serum vitamins (D, B12, folate, A, and E) and sex hormones, namely, total testosterone (TT), sex hormone-binding globulin (SHBG), and estradiol (E2). The Bayesian kernel machine regression (BKMR) model was employed to account for the combined effects of vitamins, nonlinear exposure-outcome relationships, and interactions among vitamins.

Results: A total of 231 participants aged 12-18 years were included. In the generalized linear model, vitamin A was positively correlated with TT (β = 0.421; 95% CI: 0.013, 0.829; P = 0.028) and negatively correlated with SHBG (β=-0.372; 95% CI: -0.549, -0.195; P < 0.001); folate was negatively correlated with both TT (β=-0.017; P < 0.001) and E2 (β=-0.012; P < 0.001). In the BKMR model, the combined effects of serum vitamins on TT and E2 showed a non-significant weak negative trend; no clear pattern was observed for SHBG. Folate was identified as the most important factor influencing all three sex hormones. Bivariate exposure-response functions indicated potential interactions of folate with vitamin B12 on TT and with vitamin D on E2; no vitamin interactions were observed for SHBG.

Conclusion: Complex effects of vitamins on sex hormones in adolescent males were revealed. The mechanism(s) underlying the regulation and long-term health implications will be explored in the future.