Low seminal plasma folate concentrations are associated with low sperm density and count in male smokers and nonsmokers

• Published in: Fertility and sterility Vol. 75; no. 2; pp. 252 - 259
• Main Authors: Wallock, Lynn M, Tamura, Tsunenobu, Mayr, Craig A, Johnston, Kelley E, Ames, Bruce N, Jacob, Robert A
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.02.2001; Elsevier Science
• Subjects: Adult; Biological and medical sciences; blood plasma; Diet; Folic acid; Folic Acid - analysis; Folic Acid - blood; Genotype; homocysteine; Homocysteine - blood; Humans; Male; male reproductive function; Medical sciences; Methylenetetrahydrofolate Reductase (NADPH2); microbiological assay; MTHFR polymorphism; Mutation; Oxidoreductases Acting on CH-NH Group Donors - genetics; Semen - chemistry; seminal plasma; Smoking; Sperm Count; sperm density; Spermatozoa - chemistry; Tetrahydrofolates - blood; Tobacco, tobacco smoking; Toxicology; Vitamin B 12 - blood; Vitamins - administration & dosage; homocysteine; seminal plasma; male reproductive function; sperm density; blood plasma; MTHFR polymorphism; smoking; microbiological assay; Folic acid; sperm count; Human; Reproduction; Spermatozoa; Tobacco; Toxicity; Germinal cell; Folate; Cell density; Blood plasma
• ISSN: 0015-0282; 1556-5653
• DOI: 10.1016/S0015-0282(00)01697-6

Objective: To measure folate levels in seminal plasma from smokers and nonsmokers and to evaluate relationships between seminal plasma folate levels and both folate nutriture and semen quality measures. Design: Observational study. Setting: United States Department of Agriculture, Western Human Nutrition Research Center, Presidio of San Francisco, San Francisco, California. Patient(s): Healthy male smokers (n=24) and nonsmokers (n=24). Main Outcome Measure(s): Blood levels of plasma folate and homocysteine, seminal plasma total, non-methyl- and 5-methyltetrahydrofolate concentrations, and total sperm count and density. Results: Total seminal plasma folate concentrations were on average 1.5 times higher than blood plasma folate concentrations in all men. Seminal plasma folates contained 5-methyltetrahyrdofolate (74% of total) and non-methyltetrahydrofolates (26% of total); all samples had less than four glutamyl residues. Total and 5-methyltetrahydrofolate concentrations correlated significantly with blood plasma folate and homocysteine concentrations. Seminal plasma non-methyltetrahydrofolate levels correlated significantly with sperm density and total sperm count. Seminal plasma of smokers contained a proportionally lower concentration of non-methyltetrahydrofolates compared with nonsmokers. Conclusion(s): Seminal plasma total folate and 5-methyltetrahydrofolate concentrations reflect folate nutriture. The non-methyltetrahydrofolate fraction of seminal plasma may be important for male reproductive function.