The association of reproductive hormones, thyroid function, and vitamin levels with premature ejaculation: A prospective case-control study.

Purpose: To investigate whether serum hormone (testosterone, prolactin, gonadotropins, and thyroid hormones) and vitamin (vitamin B₁₂, folic acid, and vitamin D) levels are associated with premature ejaculation (PE).

Materials and methods: This prospective case-control study included 126 patients with PE (lifelong PE [LPE] in 94 and acquired PE [APE] in 32) who presented to the urology outpatient clinic between April 2016 and January 2023 and 92 healthy men as a control group. The diagnosis of PE was based on the criteria defined by the International Society for Sexual Medicine. Serum total testosterone (TT), free and bioavailable testosterone, follicle-stimulating hormone, luteinizing hormone, prolactin, thyroid-stimulating hormone, free triiodothyronine, thyroxine (fT₄), vitamin B₁₂, folic acid, and vitamin D levels were measured.

Results: Serum TT, fT₄, and vitamin D levels were significantly higher in patients with PE than in the control group (p=0.022, p=0.002, and p=0.044, respectively). However, the serum vitamin B₁₂ level was significantly lower in the PE group (p=0.021). In the multivariate logistic regression analysis, only vitamin B₁₂ was found to be an independent risk factor for PE, with an estimated odds ratio of 0.997 (95% confidence interval 0.994-0.999, p=0.036).

Conclusions: This study demonstrated that lower vitamin B₁₂ levels are associated with the presence of PE. Therefore, we believe that it would be beneficial to consider vitamin B₁₂ levels in the evaluation of patients with PE.