Zinc is an essential trace element that is crucial for testosterone production, sperm formation, and sperm motility. Zinc deficiency is associated with low testosterone levels and poor sperm quality. Supplementing with zinc has been shown to improve sperm count, motility, and the overall hormonal profile in men.
Reference: Fallah A, Mohammad-Hasani A, Colagar AH. "Zinc is an essential element for male fertility: A review of Zn roles in men's health, germination, sperm quality, and fertilization." Journal of Reproduction & Infertility, 2018.