Vitamin B₁₂ and Semen Quality.

Area of Science:

• Reproductive Biology
• Nutritional Science
• Biochemistry

Background:

• Numerous studies have investigated vitamin B12 (cobalamin) and its effects on sperm physiology and semen quality.
• A comprehensive summary of existing research on vitamin B12's role in male reproductive health is lacking.

Purpose of the Study:

• To systematically review and synthesize the current understanding of vitamin B12's influence on semen quality and sperm physiology.
• To consolidate findings from various studies to provide an overview of vitamin B12's established and potential roles in male fertility.

Main Methods:

• Systematic literature search of Web of Science, PubMed, and Scopus databases.
• Inclusion of English language articles published from September 1961 to March 2017.
• Keywords used: "vitamin B12", "cobalamin", and "sperm"; relevant references were included for empirical and mechanistic support.

Main Results:

• Published literature predominantly indicates positive effects of vitamin B12 on semen quality.
• Benefits include increased sperm count, enhanced sperm motility, and reduced sperm DNA damage.
• Some in vivo studies have reported potential adverse effects, warranting further investigation.

Conclusions:

• Vitamin B12 may improve semen quality through enhanced reproductive organ function, reduced homocysteine toxicity, and decreased oxidative stress.
• Potential mechanisms involve reduced nitric oxide generation, lower oxidative damage to sperm, and modulation of inflammation and NF-κB activation.
• Additional clinical research is necessary to definitively confirm the beneficial effects of vitamin B12 on male fertility.