Folate is an essential B vitamin that is found in a number of fruits and leafy green vegetables. In men, consuming high levels of folic acid has been reported to boost sperm count and genetic quality. No studies indicate that excess folic acid consumed by fathers can cause birth defects, as there are a number of barriers that limit folic acid toxicity.
Sperm Health
One of the benefits of folate intake is on cellular growth and replication. The production of sperm cells by men is greatly influenced by folic acid and zinc intake, a study published in the March 2002 issue of "Fertility and Sterility" found. Folic acid and zinc supplements can boost sperm count and overall sperm health as determined by swimming motility and normal appearance, a study in the April 2006 "International Journal of Andrology" demonstrated.
Epigenetics
Folic acid supplementation has been shown change the appearance of offspring in animal models. A study published in "Nutrition Reviews" in August 2008 found that obese diabetic mice with an orange coat gave birth to similar offspring, but if the pregnant females were given folic acid supplementation, the offspring where non-diabetic, normal weight, and white in color. These changes are not caused by mutations, but by epigenetic changes that cause silencing or activation of certain genes that influence the observed traits. These studies and clinical studies of folic acid supplementation have only shown such a dramatic impacts on birth defect risk and reduction with supplementation by females.
Recommended Daily Intake
No adverse effects have been associated with excess naturally occurring folate, but too much folic acid can cause health problems. The recommended daily intake for adults is 400 mcg of folic acid, and the Food and Nutrition Board established the upper intake level of 1,000 mcg, which is 1 milligram per day for the average healthy adult. Keeping supplemental folate between the RDI and UIL is important for avoiding potential health problems.
Toxicity of Folic Acid
Folates are relatively nontoxic chemicals, but excessive doses of folic acid have been used to produce kidney failure in animal models. Doses that induce kidney damage are reported at 250 mg per 1 kg of body weight, more than 100 mg per 1 lb., in rats. The toxicity is due to crystallization of folic acid inside the kidney. The crystals cut and damage the internal structures of the kidney, leading to inflammation and acute kidney failure. An equivalent dose in humans would be more than several hundred milligrams of folic acid, but any dose above the UIL should be monitored by a health care professional.
References
- "Fertility and Sterility"; Effects of Folic Acid and Zinc Sulfate on Male Factor Subfertility: a Double-blind, Randomized, Placebo-controlled Trial; Wai Yee Wong, et al.; March 2002
- "International Journal of Andrology"; Does Folic Acid and Zinc Sulphate Intervention Affect Endocrine Parameters and Sperm Characteristics in Men?; I.M. Ebisch, et al.; April 2006
- "Nutrition Reviews"; The Agouti Mouse Model: an Epigenetic Biosensor for Nutritional and Environmental Alterations on the Fetal Epigenome; Dana C Dolinoy; August 2008
- "Nature Reviews Neuroscience"; Neural Tube Defects and Folate: Case Far from Closed; Henk J. Blom, et al.; September 2006
- "Xenobiotica"; Decreased Urinary Secretion of Belotecan in Folic Acid-induced Acute Renal Failure Rats Due to Down-regulation of Oat1 and Bcrp; Q.R. Jin, et al.; October 2009
- "Environmental Health Perspectives"; Epigenetics: The Science of Change; Bob Weinhold; March 2006
