The March of Dimes, a voluntary health agency that aims to improve the health of babies by preventing birth defects and infant mortality, has found that 40 percent of American women aged 18 to 45, took a daily multivitamin containing folic acid in 2004.
This was an increase of eight percent compared to last year and the highest level since the agency began its survey over 10 years ago.
"We're surprised at this increase, but it's good news," says Dr. Jennifer Howse, president of the March of Dimes. "It is especially important because we've been worried about the effects on mothers and babies of low-carbohydrate diets that drastically reduce grain foods enriched with folic acid, such as bread and pasta."
However, the survey revealed that 49 percent of women who have been on low-carb diets in the past six months had taken a daily multivitamin containing folic acid.
"Perhaps these women are taking their vitamins because they realize they're missing out on important food groups," said Dr Howse.
But, she ruled out the possibility that low-carb and other diets were the only reason behind the increase because at 39 percent rates of folic acid use were also higher than expected for women not dieting.
Of women who were not pregnant at the time of the 2004 survey, 37 percent reported taking a vitamin containing folic acid daily, up from 30 percent in 2003.
Morever, more women seemed to understand the importance of folic acid to the health of babies. A comparison with the eight previous surveys shows that 12 percent of women know that, to be effective, folic acid must be consumed before pregnancy. This figure was only two percent in 1995. Those who know that folic acid helps prevent birth defects increased to 24 percent in 2004, up from only four percent in 1995.
However, non-white, young and less educated women remain the least likely to take a daily folic acid supplement and their awareness of and knowledge about folic acid remained unchanged.
This is especially worrying given the fact that a survey published earlier this year suggested that black women may need to increase their folic acid intake, as they appeared to have higher levels of the amino acid homocysteine and less folic acid than white women, which could up their risk of birth defects in their infants.
The survey results were based on telephone interviews with a sample of 2012 women aged 18 to 45 conducted and are published in the most recent edition of Morbidity & Mortality Weekly Report (17 September, volume 53, No. 36). The survey was conducted for the March of Dimes by the Gallup Organization and funded by a grant from the US Centers for Disease Control and Prevention.
Daily consumption of the B vitamin folic acid beginning before pregnancy can be crucial because birth defects of the brain and spine known as neural tube defects (NTDs) occur in the early weeks following conception, often before a woman knows she is pregnant.
Each year, an estimated 2200 babies are born with these defects, and additional affected pregnancies result in miscarriage or stillbirth. To help prevent NTDs, the March of Dimes recommends that women should consume a multivitamin containing at least 400 micrograms of folic acid every day beginning before pregnancy. Women should also eat foods fortified with folic acid and foods that naturally contain folic acid, such as leafy green vegetables, and beans as part of a healthy diet.
The US, Canada and Chile currently require folic acid fortification of flour to protect women from the risk of birth defects in their babies, shown to be at higher risk if the mother is deficient in this vitamin.