Can an antioxidant multi-micronutrient supplement improve male infertility?

This study looked at whether an antioxidant multi-nutrient supplement can improve male infertility. It found that the supplement improved sperm quality and pregnancy rates in couples with male infertility.

Male infertility is a factor in half of the infertility cases. For over 40% of men with infertility, there is no clear cause of infertility. These cases are known as idiopathic male infertility. Men with idiopathic infertility often have low sperm count or quality. This may include low numbers of sperm which move normally (motility) or low numbers of sperm with a normal shape (morphology).

Oxidative damage can contribute to low sperm quality. Oxidation is a type of chemical change that can damage the membrane and tail of sperm. Sperm are particularly vulnerable to oxidation if the seminal fluid which surrounds them is low in protective antioxidants. Some studies have found that antioxidant supplements can improve male infertility. L-carnitine is an antioxidant that is also involved in how sperm and other cells use energy. It is unclear whether multi-nutrient supplements including L-carnitine can improve idiopathic male infertility.

This study included 83 men with idiopathic infertility. The female partners had normal fertility. 42 male participants took a daily multi-nutrient supplement. The supplement included L-carnitine, L-arginine, glutathione, coenzyme-Q, zinc, selenium, vitamin B9, and vitamin B12. The other 41 men took a daily placebo (inactive) pill. For at least three months before starting the study, the men did not use any other supplements or take medications related to fertility. The men and their partners were followed for six months.

At the start of the study, the two groups had similar sperm concentration and quality. After four months, the participants taking the multi-micronutrient supplement had significantly higher sperm concentration (78.7 vs. 44.0 million per mL).

After four months, the fraction of sperm that could move in a straight line was significantly higher for men taking supplements (40.8% vs. 26.1%). The amount of sperm that appeared normal under a microscope was also significantly higher for the supplement group (21.1% vs. 14.1%). After four months, significantly more men in the supplement group had normal sperm parameters (69% vs. 22%).

Couples in the supplement group were significantly more likely to become pregnant during the six-month study (23.8% vs. 4.9%). One pregnancy in the supplement group (out of ten) used in vitro fertilization (IVF). The other pregnancies were via intercourse.

This study found that a multi-nutrient supplement can improve sperm quality and conception rates for men with idiopathic infertility.

This study did not address whether other couples, besides the couple who became pregnant via IVF, used infertility treatments during the study.