The study looked at the relationship between selenium levels in semen and sperm quality in men. They found that higher selenium levels in semen were linked to better sperm density, count, motility, and viability. Fertile men had higher selenium levels in semen compared to infertile men. However, there was no significant difference in selenium levels in the blood between the two groups. Additionally, lower selenium levels in semen were associated with higher levels of oxidative DNA damage in sperm. This suggests that selenium in semen may play a role in sperm quality and DNA integrity.