Diabetes mellitus can have a detrimental effect on sperm and a study suggests that vitamin C or ascorbic acid or asorbate supplementation attenuates the detrimental effect of the disease.In the study, vitamin C supplementation significantly improved all sperm parameters including count, motility, morphology and viability in diabetic mice that would otherwise have all the parameters of sperm reduced or damaged.The dose of vitamin C used in the study was 10mg/kg/daily intra-peritoneally.The study concluded "Vitamin C, as a potent antioxidant, can attenuate detrimental effects of diabetes mellitus on the sperm parameters, chromatin quality and apoptosis in an experimental model." (David Liu, PHD)Talebi AR, Mangoli E, Nahangi H, Anvari M, Pourentezari M, Halvaei I.  Vitamin C attenuates detrimental effects of diabetes mellitus on sperm parameters, chromatin quality and rate of apoptosis in mice.  Eur J Obstet Gynecol Reprod Biol. 2014 Jul 30;181C:32-36.