. 2014 Nov 24;12:112. doi: 10.1186/1477-7827-12-112

Table 2.

Study outcomes involving oral supplementation of various antioxidants in men

Antioxidant	Study type	Patient population	Intervention (daily dose x duration)	Control group (daily dose)	Study outcome (effect on sperm parameters)	Reference
Vitamin E	Double blind, placebo cross-over, RCT	Healthy men with high seminal ROS levels (n = 30)	600 mg vitamin E x 3 months (n = 15)	Placebo (n = 15)	Improved in vitro sperm function (improved zona-binding assay)	Kessopoulou et al. [101]
Vitamin E	Double blind, placebo-controlled	Men with (n = 110) asthenozoospermia or oligoasthenozoospermia	300 mg vitamin E x 6 months (n = 52)	Placebo (n = 55)	1. Reduced MDA concentration (less LPO in spermatozoa)	Suleiman et al. [102]
					2. Improved sperm motility
					3. 20% of those on therapy achieved pregnancy
Vitamin E + Anti-Estrogen (Clomiphene citrate)	Prospective, placebo-controlled RCT	Infertile men with idiopathic oligozoospermia (n = 60)	400 mg vitamin E +25 mg clomiphene citrate x 6 months (n = 30)	Placebo (n = 30)	1. Improved sperm count and progressive motility	Ghanem et al. [103]
Vitamin E + Anti-Estrogen (Clomiphene citrate)	Prospective, placebo-controlled RCT	Infertile men with idiopathic oligozoospermia (n = 60)		Placebo (n = 30)	2. Partners had higher incidence of pregnancy	Ghanem et al. [103]
Vitamin E + selenium	Open, randomized	Volunteers and infertile men (n = 54)	400 mg vitamin E +225 μg selenium x 3 months (n = 28)	4.5 g vitamin B x 3 months (n = 26)	1. Reduced MDA concentration (less LPO in spermatozoa)	Keskes-Ammar et al. [104]
Vitamin E + selenium	Open, randomized	Volunteers and infertile men (n = 54)	400 mg vitamin E +225 μg selenium x 3 months (n = 28)	4.5 g vitamin B x 3 months (n = 26)	2. Improved sperm motility	Keskes-Ammar et al. [104]
Vitamin E + selenium	Observational study	Infertile men with idiopathic asthenozoospermia (n = 690)	400 IU vitamin E +200 μg selenium x 100 days	None	1. Improvement in sperm motility/morphology or both (53%)	Moslemi & Tavanbakhsh [105]
Vitamin E + selenium	Observational study	Infertile men with idiopathic asthenozoospermia (n = 690)	400 IU vitamin E +200 μg selenium x 100 days	None	2. Increased spontaneous pregnancy rates (11%)	Moslemi & Tavanbakhsh [105]
Vitamin E + Vitamin C	Double blind, placebo-controlled, RCT	Men (n = 31) with asthenozoospermia or moderate oligoasthenozoospermia	1000 mg vitamin C +800 mg vitamin E x 8 weeks (n = 15)	Placebo (n = 16)	No improvement in sperm parameters	Rolf et al. [106]
Vitamin E + Vitamin C	Double blind, placebo-controlled, RCT		1000 mg vitamin C +800 mg vitamin E x 8 weeks (n = 15)	Placebo (n = 16)	No improvement in 24 h sperm survival rate	Rolf et al. [106]
Vitamin E + Vitamin C	Observational study, double-blind	Men with elevated sperm DNA fragmentation (≥15%) who have unexplained infertility	1000 mg vitamin C +1000 mg vitamin E x 2 months (n = 32)	Placebo (n = 32)	Reduced percentage of DNA-fragmented sperm (TUNEL test)	Greco et al. [107]
Vitamin E + Vitamin C	Observational study involving assisted conception treatment	Men with elevated sperm DNA fragmentation (≥15%) who failed their 1^st ICSI attempt	1000 mg vitamin C +1000 mg vitamin E x 2 months (n = 38)	None	1. Reduced percentage of DNA-fragmented sperm (TUNEL test)	Greco et al. [108]
Vitamin E + Vitamin C	Observational study involving assisted conception treatment		1000 mg vitamin C +1000 mg vitamin E x 2 months (n = 38)	None	2. Marked improvement in implantation and clinical pregnancy rates in the 2^nd ICSI attempt vs 1^st attempt	Greco et al. [108]
Vitamin C		Men with sperm agglutination (>25%) (n = 30)	200 mg vitamin C or 1000 mg vitamin C	Placebo	Improved sperm motility, viability, morphology after 4 weeks (more prominent improvement in 1000 mg vitamin C vs. 200 mg vitamin C)	Dawson et al. [109]
Vitamin C		Men who are heavy smokers (n = 75) with normal reproductive function	200 mg vitamin C or 1000 mg vitamin C	Placebo	1. Improved sperm agglutination	Dawson et al. [110]
					2. Improved 24 h viability
					3. Improved sperm morphology
Folic acid + zinc sulphate	Double blind, placebo-controlled, RCT	Fertile (n = 108) and subfertile men (n = 103)	5 mg folic acid, 66 mg zinc sulphate or 5 mg folic acid +66 mg zinc sulphate x 26 weeks	Placebo or placebo + placebo	Increased sperm concentration in subfertile and fertile males after combined treatment	Wong et al. [111]
Folic acid + zinc sulphate	Double blind, placebo-controlled	Fertile (n = 47) and subfertile men (n = 40)	5 mg folic acid +66 mg zinc sulphate x 26 weeks	Placebo	Increased sperm concentration in infertile males, but not fertile males	Ebisch et al. [112]
Folic acid + zinc sulphate	Double blind, placebo controlled, RCT	Subfertile men with OAT (n = 83)	5 mg folic acid +220 mg zinc sulphate x16 weeks	Placebo	Zinc sulfate + folic acid did not improve sperm quality in men with OAT (severely compromised sperm parameters)	Raigani et al. [113]
Folic acid + zinc sulphate	Prospective, randomized controlled	Men with palpable varicocele (grade III) who underwent surgical repair of varicocele (n = 160)	5 mg folic acid (n = 26), 66 mg zinc sulphate (n = 32) or 5 mg folic acid +66 mg zinc sulphate (n = 29) x 6 months	Placebo (n = 25)	1. Zinc sulfate + folic acid improved sperm parameters and improved varicocelectomy outcomes	Azizollahi et al. [114]
Folic acid + zinc sulphate	Prospective, randomized controlled			Placebo (n = 25)	2. Improved protamine content and halo formation rate	Azizollahi et al. [114]
Coenzyme Q ₁₀	Systematic review and meta-analysis (3 RCTs)	Infertile men	CoQ₁₀ (n = 149)	Controls (n = 147)	1. Improved seminal CoQ₁₀ levels	Lafuente et al. [115]
					2. Increased sperm concentration
					3. Increased sperm motility
					4. No increase in pregnancy rates
					5. Data on live births were lacking
Coenzyme Q ₁₀	Double blind, placebo-controlled, RCT	Men with iOT (n = 60)	200 mg CoQ₁₀ x 3 months (n = 30)	Placebo (Lactose) (n = 30)	1. Increased levels of CoQ₁₀ in seminal plasma	Nadjarzadeh et al. [116]
					2. Decreased 8-isoprostane levels (biomarker of LPO) (attenuation of OS in seminal plasma)
					3. Increased sperm forward and total motility
					4. Increased catalase, SOD activity
Coenzyme Q ₁₀	Double blind, placebo-controlled, RCT	Men with iOAT (n = 47)	200 mg CoQ₁₀ x 12 weeks	Placebo	1. Reduced TBARS (reduced plasma MDA levels)	Nadjarzadeh et al. [117]
Coenzyme Q ₁₀	Double blind, placebo-controlled, RCT	Men with iOAT (n = 47)	200 mg CoQ₁₀ x 12 weeks	Placebo	2. Increased TAC in seminal plasma	Nadjarzadeh et al. [117]
Coenzyme Q ₁₀	Double blind, placebo-controlled, RCT	Men with iOAT (n = 228)	200 mg ubiquinol x 26 weeks (n = 114)	Placebo (n = 114)	Improved sperm quality (density, motility, normal strict morphology)	Safarinejad et al. [118]
Coenzyme Q ₁₀	Double blind, placebo-controlled, RCT	Men with idiopathic infertility (n = 60)	200 mg CoQ₁₀ x 6 months	Placebo	1. Increase in CoQ₁₀ and ubiquinol in seminal plasma and spermatozoa	Balercia et al. [119]
Coenzyme Q ₁₀	Double blind, placebo-controlled, RCT	Men with idiopathic infertility (n = 60)	200 mg CoQ₁₀ x 6 months	Placebo	2. Increase in spermatozoa motility	Balercia et al. [119]
Coenzyme Q ₁₀	Prospective	Men with iOAT (n = 212)	300 mg CoQ₁₀ x 26 weeks (n = 106)	Placebo (n = 106)	1. Improved sperm density, motility, normal strict morphology	Safarinejad [120]
Coenzyme Q ₁₀	Prospective	Men with iOAT (n = 212)	300 mg CoQ₁₀ x 26 weeks (n = 106)	Placebo (n = 106)	2. Improved acrosome reaction	Safarinejad [120]
Coenzyme Q ₁₀	Open-label, prospective	Men with iOAT (n = 287)	600 mg CoQ₁₀ x 12 months (n = 106)	None	1. Improved sperm quality (concentration, progressive motility, normal morphology)	Safarinejad [121]
Coenzyme Q ₁₀	Open-label, prospective	Men with iOAT (n = 287)	600 mg CoQ₁₀ x 12 months (n = 106)	None	2. Improved pregnancy rates	Safarinejad [121]