It turns out that women who have a vitamin B12 (folic acid) deficiency early in their pregnancy may have an increased risk of having children with disabling or even fatal neural tube defects, as determined by a study published in the journal Pediatrics. The neural tube is the part of the fetus that will develop into the brain and spinal cord. Under normal conditions, the skull and spine form around the brain spinal cord, respectively, followed by the skin to form the completed neural tube.

When this process is not accomplished properly, neural tube defects (NTD) can ensue. They include anencephaly, where the brain and skull are severely underdeveloped, as well as spina bifida.

Spina bifida is a condition that develops in early pregnancy where the bones of the spine do not form properly around the spinal cord, resulting in the cord bulging out through. Though rates of spina bifida have been declining, it remains one of the most common birth defects, affecting some 1500 to 2000 of the over 4 million births each year.

In the study, researchers compared folic acid levels in women who had healthy pregnancies with women who had either given birth to children with neural tube defects or were pregnant with children who had neural tube defects. Covering a seven year span, it turns out that the women who had the lowest levels of folic acid in their diet (below 150ng/liter) had five times more likely to have children with neural tube defects than women who had the highest level of folic acid in their diet (greater than 400ng/liter). When women consumed what was considered a lower (but not the lowest) level of folic acid, they were three times at greater risk.

NTDs can be detected by way of prenatal tests, and surgical intervention can address certain complications, but the ideal situation would be to lower a mother’s risk by ensuring the proper amount of the nutrient in her diet. One of the problems that arises is the critical time period for folic acid consumption is before pregnancy and during the first six weeks, which is often a period when a woman is unaware that she is pregnant.

It is for this reason that doctors recommend that women of child bearing age or those who are trying to become pregnant make sure they get enough of folic acid in their diet. Good sources include meat, dairy and eggs. Vegans and vegetarians can find it in fortified foods and supplements.

In fact, synthetic versions of folic acid and food fortification have resulted in a significant reduction the incidence of neural tube defects.