Male fertility is influenced by many factors:
A 2016 evidence-based review by Ahmadi et al., published in the International Journal of Reproductive Biomedicine, reviewed research examining antioxidant supplementation and male fertility. The review noted that oxidative stress and reduced seminal antioxidant capacity may play an important role in a substantial proportion of male infertility cases. The authors reviewed research involving antioxidants and nutrients including CoQ10, folic acid, L-carnitine, multivitamins, N-acetyl cysteine (NAC), selenium, vitamin B12, vitamin E, and zinc.
Across the studies reviewed, antioxidant supplementation was associated in many cases with improvements in semen parameters such as sperm concentration, motility, morphology, and, in some studies, sperm DNA integrity. The review also found that results were not uniform across every study, highlighting the importance of individualized care and realistic expectations.
 

Lifestyle Matters!
Nutrition is only one piece of the fertility picture.
Lifestyle and environmental factors that may contribute to oxidative stress and affect sperm health can include:
Chronic stress, smoking and tobacco exposure, excessive alcohol intake, obesity and metabolic health, poor nutrition, environmental or occupational exposures, exposure to certain pesticides and chemicals & other underlying health conditions.