Clinical studies show that daily supplementation with selenium can improve male fertility [Moslemi et al.; Safarinejad & Safarinejad; Scott et al.].
- Selenium is essential for sperm function and male fertility.
- Selenium deficiency has been associated with reproductive difficulty in cattle, chickens, mice, pigs, rats, and sheep; selenium supplementation has improved reproductive performance in mice and sheep and mice [Moslemi et al.].
- The mechanism linking adequate selenium status to improved sperm quality may be the role of selenium containing antioxidant seleno-enzymes in reducing the extent of oxidative damage caused by harmful free radicals [Moslemi et al.].
- Results from a comparative study have shown that supplementation with a selenium yeast preparation resulted in significant reductions in biomarkers of oxidative stress but that supplementation with pure selenomethionine did not. The results suggest that selenium-containing compounds in the selenium yeast preparation, i.e. compounds other than selenomethionine, may account for the decrease in oxidative stress [Richie et al.].
Selenium Supplementation of Men in Iran in 2009
In a 2009 study lasting 26 weeks, researchers in Teheran randomly assigned infertile men, average age 31 years, range 25-48 years, to the following groups [Safarinejad & Safarinejad]:
- selenium supplementation group (n=116; dosage = 200 mcg/day)
- N-acetyl-cysteine group (n=118; dosage = 600 mg/day)
- selenium supplementation group (n=116; dosage = 200 mcg/day) plus N-acetyl-cysteine (dosage = 600 mg/day)
- placebo group (n=118)
Outcomes of the 2009 Iranian selenium study:
- All semen parameters significantly improved with the selenium treatment and with the N-acetyl-cysteine treatment.
- Administering selenium plus N-acetyl-cysteine resulted in additive beneficial effects.
- There was a significant positive correlation between the seminal plasma concentrations of selenium and N-acetyl-cysteine and the semen parameters.
- There was a strong correlation between the sum of the selenium and N-acetyl-cysteine concentrations and the mean sperm concentration, sperm motility, and percentage of normal morphology sperm.
Selenium Supplementation of Men in Iran 2011
In an open-label study of 690 infertile men, average age 28.5 years, range 20-45 years, who received a daily selenium supplement (200 mcg) together with a daily synthetic vitamin E (400 units, α-tocopherol) for at least 100 days, the researchers concluded that supplemental selenium and vitamin E improve semen quality and have beneficial effects on sperm motility [Moslemi et al.].
Outcomes of the 2011 Iranian selenium study
- The combination of selenium and vitamin E was associated with a significant increase in mean sperm motility from baseline.
- The combination of selenium and vitamin E was associated with a slight but statistically significant increase in the normal morphological sperm ratio from baseline.
Selenium Supplementation of Men in Scotland in 1998
In a study conducted in the Glasgow Royal Infirmary, 64 men, average age 33 years, were randomly assigned to one of three test groups [Scott et al.]:
- Daily supplementation with 100 micrograms of selenium
- Daily supplementation with 100 micrograms of selenium plus 1 milligram Vitamin A, 10 milligrams Vitamin C, and 15 milligrams Vitamin E
- Daily supplementation with a placebo
Outcomes of the 1998 Scotland selenium study:
- Plasma selenium concentrations increased significantly in groups 1 and 2, rising from sub-normal levels (< 70-80 mcg/L) to normal levels (> 100 mcg/L).
- Sperm motility increased significantly in the men who received a daily selenium supplement and did not increase in the men in the placebo group.
- The combination of vitamins with the selenium supplement did not have any discernible additional effect on sperm motility.
U-Shaped Curve Relating Selenium Status to Health Benefits
Professor Margaret P. Rayman, University of Surrey, has suggested in a 2012 seminal article published in The Lancet that selenium status in the range roughly from 100 – 170 mcg/L is most likely to confer health benefits [Rayman, 2012, Figure 3, page 4].
Best form of Selenium supplement
A 2014 comparative study has shown that an organic high-selenium yeast formulation gives significant protection against oxidative stress damage while an exclusively selenomethionine formulation does not. The selenium-enriched yeast product contains selenium species beyond just selenomethionine and these other selenium species seem to have the beneficial effect [Richie et al.].
- There is evidence from clinical studies that daily selenium supplementation improves sperm motility and is associated with improved male fertility.
- It is possible that reproduction outcomes can be improved further if both partners receive daily selenium supplements. There are strong indications that sufficient selenium is needed for the proper growth, maturation, and replication of oocytes; however, the mechanisms are not yet fully understood [Mintziori et al.].
Agarwal A, Mulgund A, Hamada A, Chyatte MR. A unique view on male infertility around the globe. Reprod Biol Endocrinol. 2015;13:37.
Mintziori G, Mousiolis A, Duntas LH, Goulis DG. Evidence for a manifold role of selenium in infertility. Hormones (Athens). 2020 Mar;19(1):55-59.
Moslemi MK, Tavanbakhsh S. Selenium-vitamin E supplementation in infertile men: effects on semen parameters and pregnancy rate. Int J Gen Med. 2011;4:99-104.
Rayman MP. Selenium and human health. Lancet. 2012 Mar 31;379(9822):1256-68.
Richie JP Jr, Das A, Calcagnotto AM, Sinha R, Neidig W, Liao J, Lengerich EJ, Berg A, Hartman TJ, Ciccarella A, Baker A, Kaag MG, Goodin S, DiPaola RS, El-Bayoumy K. Comparative effects of two different forms of selenium on oxidative stress biomarkers in healthy men: a randomized clinical trial. Cancer Prev Res (Phila). 2014 Aug;7(8):796-804.
Safarinejad MR, Safarinejad S. Efficacy of selenium and/or N-acetyl-cysteine for improving semen parameters in infertile men: a double-blind, placebo controlled, randomized study. J Urol. 2009;81(2):741-51.
Scott R, MacPherson A, Yates RW, Hussain B, Dixon J. The effect of oral selenium supplementation on human sperm motility. Br J Urol. 1998 Jul;82(1):76-80.
The information presented in this review article is not intended as medical advice and should not be used as such.
30 May 2021