Selenium Supplementation and Male Infertility

Clinical studies show that daily supplementation with selenium can improve male fertility [Moslemi et al.; Safarinejad & Safarinejad; Scott et al.].

Stork bringing baby
Sperm motility is a parameter of sperm analysis used to evaluate the ability of sperm to move in a forward direction. Poor sperm motility is associated with diminished male fertility. Adequate serum selenium status (> 90-100 mcg/L) is associated with improved sperm quality and improved sperm motility.
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]:

  1. selenium supplementation group (n=116; dosage = 200 mcg/day)
  2. N-acetyl-cysteine group (n=118; dosage = 600 mg/day)
  3. selenium supplementation group (n=116; dosage = 200 mcg/day) plus N-acetyl-cysteine (dosage = 600 mg/day)
  4. 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.]. read more

Selenium Status and Male Infertility

Storck bringing baby
Without optimal selenium status, the stork cannot bring the baby.  Selenium supplementation can improve male performance in reproduction by protecting immature spermatozoa and by improving sperm motility.

Approximately 50% of the problems in couples unable to conceive are caused by male infertility. Something like two percent of all men have sub-optimal sperm parameters [Kumar and Singh 2015]:

  • low sperm concentration
  • poor sperm motility
  • abnormal sperm cell morphology
  • or combinations thereof

Selenium Status and Male Infertility

The role of selenium in male infertility has not been fully explained. However, some data show that selenium plays a role in the protection of sperm cells against oxidative stress [Buhling 2019].

In particular, the selenoproteins glutathione peroxidase GPx4 and selenoprotein P are essential to the process of sperm development and male fertility [Rayman 2012].

      • In the testes, the GPx4 selenoproteins protect immature spermatozoa cells against oxidative damage.
      • GPx4 selenoproteins are also important for good sperm motility.
      • Selenoprotein P supplies selenium to the testes.

      Selenium is a trace mineral that is essential for many important processes in the human body. Selenium is incorporated into enzymes that function as antioxidants. The balance between protective antioxidants and harmful free radicals in cells plays a decisive role in the prevention of disease [Rayman 2002]. read more

Selenium Supplementation and Sperm Quality Parameters

Supplementation with selenium and with Coenzyme Q10 has beneficial effects on sperm count, sperm motility, and sperm morphology. There seems to be a special interrelationship between selenium and Coenzyme Q10 such that sufficient concentrations of each are needed for the optimal function of the other.

Data from two randomized controlled trials have shown that selenium supplementation has the following significant beneficial effects [Salas-Huertos]:

  • improved sperm volume and concentration
  • improved sperm motility
  • improved sperm morphology

Selenium supplementation at 100 micrograms per day for 3 months improved sperm motility and increased the chance of conception.  Selenium supplementation at 200 micrograms per day for 6 months improved semen volume, total sperm count and concentration, and sperm morphology [Salas-Huertos].

Data from five other randomized controlled trials have shown that Coenzyme Q10 supplementation is significantly associated with the following beneficial effects:

  • improved sperm count
  • improved sperm concentration
  • improved sperm motility
  • improved sperm morphology

The Coenzyme Q10 supplementation was most effective when the supplementation was in the range of 200 – 300 milligrams per day (in divided doses) for at least 3 months and especially after 6 months [Salas-Huertos]. read more

Selenium Supplementation for Premature Neonates

Preterm neonates are babies born more than three weeks before the normal term, i.e. born before the 37th week of gestation. Sepsis – the condition caused by harmful bacteria entering the blood circulation – is one of the complications associated with premature birth. Selenium supplementation can reduce the risk of late-onset sepsis in preterm neonates.

Selenium supplementation reduces the risk of sepsis in premature babies.

Three studies carried out in low-selenium countries – Australia, New Zealand, and India – have shown a positive effect of selenium supplementation in reducing the incidence of sepsis in premature babies [Daniels; Darlow; Aggarwal].

Selenium supplementation – both selenium fed orally and selenium fed parenterally – significantly improved the selenium status of premature babies and reduced the incidence of “late onset” sepsis [Darlow].

In none of the three clinical studies were there any adverse reactions to the selenium supplementation [Daniels; Darlow; Aggarwal].

Increased Risk of Sepsis in Premature Babies Without Selenium Supplementation

“Late onset” sepsis presents, typically, one week or more following birth and is caused by exposure to infection in the hospital.  A “late onset” sepsis occurs in about one out of five premature babies with a birth weight below 1500 grams (about 3 pounds and five ounces). read more

Serum selenium status and gestational diabetes

The prevalence of gestational diabetes varies from region to region of the world from below 5% of pregnancies to below 10% to as high as 20%. Gestational diabetes increases the risk of type 2 diabetes and metabolic syndrome for the mother and increases the risk of acute and long-term adverse metabolic disorders in the offspring. A recent meta-analysis reveals that women with gestational diabetes typically have significantly lower serum selenium concentrations.

Typically, the serum selenium concentration levels are significantly lower in women with gestational diabetes than in healthy pregnant women.  The differences are especially remarkable in non-Caucasian pregnant women and in pregnant women in the third trimester.  That is the finding of a recent meta-analysis and systematic review of the relevant literature from observational studies [Kong 2016].

Selenium and gestational diabetes

Gestational diabetes is defined as any degree of glucose intolerance that occurs with the onset of pregnancy.  A physiological insulin resistance beginning in the second trimester and progressing through the third trimester is fairly typical of pregnancies.  Expecting mothers generally need increased insulin secretion to maintain normal blood glucose levels.  Impairment of the needed compensatory increases in insulin secretion leads to a diagnosis of gestational diabetes [Kong 2016]. read more

Selenium helps to avoid pregnancy complications

Adequate intakes of selenium can help to reduce the risk of some of the more serious complications of pregnancy. Studies done with an organic high-selenium yeast supplement have yielded encouraging results.

Women who have first-trimester miscarriages or recurrent miscarriages have been found to have significantly lower selenium status than women who do not miscarry.  Professor Margaret Rayman points out that blood selenium concentrations are typically lower during pregnancy, in part because there is an expansion of the volume of blood.  However, increased inflammation – implicated in miscarriages – could also be a cause of reduced circulating selenium [Rayman 2012].

For this article, I have searched the Medline database for results from randomized controlled studies involving selenium supplementation of low selenium status pregnant women.  There have been a number of interesting results.

Selenium and oxidative stress in pregnant women
Dr. Tara and a team of researchers did a simultaneous assay of pro-oxidant burden and antioxidant capacity in a total of 166 first-time-pregnant women.  In their first trimester, the women were randomly assigned to an active treatment group receiving 100 micrograms of a yeast-based selenium preparation (n=83) or placebo (n=83) per day until delivery. read more

Selenium and heavy metals and childbirth

Studies show that higher concentrations of dangerous heavy metals — cadmium, mercury, and lead — in the blood of the mother are likely to be duplicated in the umbilical cord blood, in the blood of the fetus, in the breast milk, and in the blood of the newborn child, with potentially harmful long-term consequences for the child. There is evidence that selenium binds with cadmium and mercury and enables their elimination from the mothers’ bodies.

Early exposure to natural elements that are toxic – cadmium, mercury, and lead – can have long-term adverse health consequences.  Children exposed to these elements while still in the uterus and while breast-feeding may suffer lasting damage to the brain and nervous system and to the kidneys and liver.  The question is: to what extent can selenium supplementation reduce the risk of toxic damage?

Given the dangerous nature of these poisonous heavy metals – cadmium, mercury, and lead – both for the mother and for the fetus and the neonate, it is difficult to carry out randomized controlled studies.  Instead, the best evidence we have for the beneficial effects of selenium supplementation comes from studies that relate the degree of exposure and the selenium status of the mother and the child. read more

Selenium and the risk of pre-eclampsia

Pre-eclampsia is a serious condition that causes high blood pressure in pregnant women who did not have high blood pressure prior to their pregnancies. The high blood pressure typically develops after the 20th week of pregnancy. Research studies show that a daily selenium supplement can reduce the risk of pre-eclampsia.

There is a clear relationship between a pregnant woman’s selenium status and her risk of pre-eclampsia.   Observational studies show that low selenium status is associated with a greater risk of pre-eclampsia.  Studies of selenium supplementation have shown reduced incidence of pre-eclampsia [Xu].

What is pre-eclampsia?
Pre-eclampsia is a complex condition characterized by the onset, around week 20 of the pregnancy, of the following symptoms:

  • abnormally high protein levels in the urine (indicating possible damage to the kidneys)
  • systolic blood pressure greater than 140 mmHg or diastolic blood pressure greater than 90 mmHg when measured twice with an interval of at least 4–6 hours and not more than 7 days apart [Uzan]
  • severe headaches
  • blurred vision
  • decreased platelet levels in the blood [Mayo Clinic]

Pre-eclampsia seems to be caused by an abnormal development of the new blood vessels that are needed to carry blood to the placenta.  The new blood vessels are narrower than they should be, and they respond differently to hormonal signaling [Mayo Clinic]. read more

Selenium and male infertility

The selenium containing selenoprotein glutathione peroxidase 4 (GPx4) is present in sperm cells at surprisingly high levels. Biochemists say that GPx4 carries out two functions in sperm cells. It protects the developing sperm calls against oxidative damage caused by toxic peroxides, and it contributes later to the structural integrity of the mature sperm cells [Strauss].
Here is a little-known fact.  Human testicles contain high concentrations of one of the important selenium containing antioxidant enzymes, the selenoprotein glutathione peroxidase number 4 (GPx4).  Furthermore, the testicles have special receptors for another of the important selenoproteins, the selenoprotein P [Rayman 2012].

Adequate intakes of selenium for the synthesis of the selenoproteins are necessary to produce mature and viable sperm.  The selenoprotein GPX4 seems to be indispensable:

  • to the development and maturation of the sperm cells
  • to the antioxidant protection of the sperm cells
  • to the structural cohesiveness of the sperm cells
  • to the motility and viability of the sperm cells [Foresta]

Selenium and semen quality
What are we talking about here?  Let’s define some terms that are relevant to male fertility.

Our bodies produce semen by combining sperm cells from the testicles with various fluids from the seminal vesicles, the prostate, and the two small glands called Cowper’s glands.  The semen needs to contain high counts of sperm cells – perhaps 200 million plus – and needs to contain sperm cells capable of good motility if one of the sperm cells is to succeed in reaching and fertilizing the mature female egg. read more

Dr. Gerhard N. Schrauzer – renowned selenium researcher

Dr. Gerhard N. Schrauzer was the first scientist to study the biological functions of selenium systematically. He was known internationally for his pioneering work in the cancer-protective properties of selenium. (Picture: Cancer Research, vol. 49 no. 23, Dec. 1, 1989)

Dr. Gerhard N. Schrauzer was the grand old man of selenium science.  Actually, he was the grand old man of trace element research in the United States for 30 years or more.  He was one of the pioneers and one of the major figures in selenium research.   Let’s take a look at the useful contributions of information to the selenium supplementation knowledge base that Dr. Schrauzer made.

First, who was Dr. Schrauzer in the context of selenium research?
Dr. Schrauzer did his graduate study in chemistry at the University in Munich, Germany. He was awarded his Ph.D. summa cum laude.  From 1966 to 1994, he was a chemistry and biochemistry professor at the University of California in San Diego (UCSD). After his retirement, he was a professor emeritus at UCSD. read more