A healthy diet should be high in folate
Folic acid is one B-vitamin that is especially important for young and old alike. Also in a form called folate, this vitamin plays a role in numerous critical body functions that help to prevent many of today's common ailments.
Question: Why is folic acid needed?
Answer: Folate is required to make DNA -- the genetic blueprints for how our body is supposed to work. Cells that are rapidly dividing, such as red blood cells, intestinal cells and those in a developing fetus, have the greatest need for folate.
Q: How does pregnancy affect folic acid needs?
A: Pregnancy increases folic acid needs for two reasons. Because folate is needed for the production of red blood cells, a pregnant woman could develop anemia without adequate folate. Second, folate is needed for normal development of the fetal spinal cord and heart, among other parts. Without adequate folate, the child could be born with spina bifida and congenital heart defects.
Consequently, it is commonly recommended that women take a supplement of 400 micrograms (mcg) per day to make sure that they meet the recommendation of 600 mcg per day during pregnancy. This is the amount of folic acid normally found in a prenatal vitamin-mineral supplement.
Q: What role does folate play in preventing disease in adults?
A: Folate is probably best known for helping to reduce the risk of heart and blood vessel diseases. It likely does this by preventing the accumulation of a compound called homocysteine. About one out of seven people over the age of 65 years has elevated levels of homocysteine. For these individuals, the doctor might recommend a supplement to provide an adequate intake of folate along with vitamins B-2, B-6 and B-12 to help lower homocysteine.
Some studies also indicate that the risk of various cancers is increased if folate is low in the diet. In particular, colon cancer risk increases. Also, women infected with the rather common human papilloma virus, or HPV, are five times more likely to develop precancerous cervical dysplasia if their folate status is down.
Q: What foods supply folic acid?
A: Many fortified breakfast cereals meet the adult daily recommendation of 400 mcg. A cup of most types of cooked beans provides 200 to 300 mcg, and a cup of most cooked green vegetables delivers 100 to 200 mcg.
Some recent resaearch questions high intake of supplemental folic acid, finding that supplements providing 1,000 mcg per day do not decrease the risk of lower intestinal cancer and might even slightly increase risk.
Alan Titchenal, Ph.D., C.N.S. and Joannie Dobbs, Ph.D., C.N.S. are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii-Manoa. Dr. Dobbs also works with University Health Services.