Low vitamin B12 may lead to higher risk of testosterone deficiency, infertility among men
Writing in The Journal of Nutrition, researchers from the University of Toronto and Mount Sinai Hospital suggest that even a slight increase in vitamin B12 concentrations may contribute to a significant decrease in the likelihood of low testosterone levels.
“[This is] the first comprehensive investigation exploring the relationship between serum vitamin B12 and several key male reproductive hormones in humans,” they wrote. “Our findings also suggest that B12 concentrations may need to be assessed as part of routine measures in the management of male infertility.”
Enhancing knowledge in this field could help to incorporate nutritional interventions into male infertility management, as well as support favorable outcomes from assisted reproductive technologies.
The research was funded by the Canadian Federation for Dietetic Research and the Allen Foundation Inc.
A lack of research
Clinicians define infertility as the inability to achieve pregnancy after consistent unprotected sexual intercourse over a year. Infertility affects 16% of North American couples, and male factor infertility accounts for approximately 30% of those cases.
“The decline in male fertility, characterized by factors such as diminished sperm quality and hypogonadism, has become a growing concern,” the researchers explained. “Previous research has identified a significant decrease in testosterone concentrations among males, independent of age, attributed to various influences including health, environmental factors and dietary choices.”
Vitamin B12, an essential water-soluble vitamin, influences several physiological functions, including DNA synthesis and red blood cell maturation. However, the scientists acknowledged that there is a gap in information regarding how micronutrients impact male reproductive hormones. Some studies suggest vitamin B12 as adjuvant nutritional therapy for male infertility because it may improve sperm health.
“Only one study involving a small group of 26 males with infertility has examined the relationship between vitamin B12 and reproductive hormones,” the researchers noted. “A comprehensive review on vitamin B12 and male reproductive health, highlighted this scarcity in research on the impact of vitamin B12 on reproductive hormones.”
They added that the goal of their study was to determine associations between vitamin B12 concentrations and reproductive hormones in men experiencing infertility.
Study details
Participants in the study included 303 males experiencing infertility who were recruited from the Murray Koffler Urologic Wellness Center at Mount Sinai Hospital in Toronto, Canada.
The study excluded men who had “undergone postoperative procedures; experienced physical impairments leading to infertility; were unable to provide venous blood or semen samples; had missing data; had recently used fertility-related medication within the last six months, had undergone vasectomy; received testicular cancer radiation therapy <4 years ago; or had conditions such as Klinefelter Syndrome, Y chromosome microdeletions, or cystic fibrosis.”
Nearly 48% of participants were considered overweight and 24% were categorized as obese.
After participants completed a computerized health questionnaire, their blood samples were collected to assess serum vitamin B12 and reproductive hormone concentrations, including FSH, LH, total testosterone (TT), prolactin and estradiol. Approximately 25% of participants had elevated FSH, 34% had elevated LH, 30% had low testosterone, 2.6% showed elevated prolactin concentrations and 75% displayed elevated estradiol concentrations.
“We discovered that individuals in either the mid- or highest tertiles of serum vitamin B12 had significantly lower odds of experiencing testosterone deficiency compared with those in the lowest tertile of vitamin B12,” the researchers wrote. “Although the highest tertile showed the lowest odds, it is noteworthy that even individuals in the mid-tertile experienced a significant reduction in the odds of TT deficiency. This suggests that even a slight increase in vitamin B12 concentrations may contribute to a notable decrease in the likelihood of testosterone deficiency.”
Source: The Journal of Nutrition
doi: 10.1016/j.tjnut.2024.06.013
"Vitamin B12 Is Associated with Higher Serum Testosterone Concentrations and Improved Androgenic Profiles Among Men with Infertility"
Authors: Matineh Rasegar Panah et al.
