By now, you should be suspicious of the idea that pills or supplements offer better nutrition than real food. And yet, I realize the possibility of a magic bullet that would allow us to live well on junk food remains tantalizing, even irresistible. But it is becoming clear that supplements may fail to provide the expected nutritional boost on the one hand, and actually do harm by providing excess doses, on the other. In an ongoing effort to burst some nutritional fantasy bubbles, here’s some guidance on folic acid.
Folic acid is an important B-vitamin, and it is particularly critical for pregnant mothers: a deficiency is associated with increased occurrences of spina bifida. This condition occurs when the lower end of the neural tube fails to close properly, leaving the spinal cord exposed to the amniotic fluid. Concern over this issue led several countries to require that the grains used to make bread, breakfast cereals, etc. be fortified with folic acid. And these programs have been successful. Since 1998 when the fortification program began in the U.S., there has been a 31% decrease in spina bifida cases in babies. There is also some possibility that high doses may help to reduce cardiovascular diseases, strokes and mental decline with aging.
It was once believed that folic acid was the active nutrient, but it is now understood that its important role is as the precursor of folate, which is found naturally in leafy greens such as spinach (think of folate = foliage) and oranges. Folic acid is converted into folate in the liver. However, the liver is limited in how much folic acid it can handle. Excess amounts end up, unmetabolized, in the blood and urine.
Researchers Steven Bailey and Bruce Ames (of the University of South Alabama and the University of California, respectively) warn that consuming more than 1 mg a day of folic acid, from any source, will result in higher levels of the unmetabolized chemical circulating in the body. This is undesirable, as high doses are suspected of exacerbating certain cancers. There is enough concern on this matter that some countries, and the European Union, have discontinued programs to fortify grains with folic acid.
The recommended daily dose of folic acid is 0.4 mg. In most people, this amount will be converted into folate. However, the quantities put into cereals sold in America can result in the consumption of up to 0.8 mg per standard serving. Not only do many Americans eat more than the standard serving, but many are consuming additional amounts from supplement pills. Most vitamin pills contain at least the daily recommended dosage, and many contain multiples of the daily amount.
Ensuring sufficient folic acid/folate consumption for pregnant women and aspiring mothers remains important. The recommended dosage is twice that for others, or 0.8mg. The researchers stress that these individuals should not avoid folic acid supplements. But the rest of us need to focus on getting our vitamins from our dinner plates, and not from a bottle.