Vitamin B12 Can Prevent Major Birth Defect

March 16, 2009

Before becoming pregnant, women need to get enough vitamin B12 in addition to folic acid to cut their risk of having a baby with a serious birth defect of the brain and spinal cord, researchers said on Monday. Irish women with the lowest vitamin B12 levels were five times more likely to have a baby with a neural tube defect than those with the highest levels, the researchers report. Neural tube defects can lead to lifelong disability or death. The two most common defects are spina bifida, in which the spinal cord and back bones do not form properly, and anencephaly, a fatal condition in which the brain and skull bones do not develop normally. Dr. James Mills of the U.S. National Institutes of Health, one of the researchers, said the study showed that vitamin B12 deficiency was a risk factor for neural tube defects independent of folic acid, another B vitamin. Many women now know of the importance of folic acid for preventing birth defects and there has been a drop in neural tube defects due to its usage and availability in fortified grains. Mills said he hopes that awareness of the similar role of vitamin B12 can reduce neural tube defects further.  

The study involved almost 1,200 women in Ireland who gave blood samples during early pregnancy, which were analyzed to determine vitamin B12 levels. The women in the lowest 25 percent of vitamin B12 levels were five times more likely than those in the highest 25 percent to have had a baby with a neural tube defect. The researchers suggested that women have vitamin B12 levels above 300 nanograms per liter before getting pregnant. This is important because these birth defects happen very early on in pregnancy before women may even know they are pregnant.