In the present cross-sectional study involving infertile men (normozoospermic and those with one or more altered semen parameters), it was observed that men with one or more semen abnormalities had significantly lower vitamin D levels, higher FSH and LH levels, and lower serum TT levels compared to infertile men with normal semen parameters. Patients with lower vitamin D levels (<12 ng/mL) had significantly lower sperm count, motility (both total and linear progressive), normal morphology, and lower TT levels compared to patients with higher serum vitamin D levels (>12 ng/mL). This evidence concerns the gene PLOD1 and Infertility.