Carotenoids / Antioxidants / Vitamin A / Humans / Fertility and Sterility / Male / Vitamin E / Male Infertility / Clinical Sciences / Uric Acid / Ascorbic Acid / Public health systems and services research / Semen / Spermatozoa / Seminal Plasma / Male / Vitamin E / Male Infertility / Clinical Sciences / Uric Acid / Ascorbic Acid / Public health systems and services research / Semen / Spermatozoa / Seminal Plasma