A new study has found a possible risk for pregnant women who may eat little to no meat or animal-based products.

In the March issue of Pediatrics, researchers found children born to women with low blood levels of the vitamin B12 shortly before and after conception may have an increased risk of a neural tube defect.

This birth defect can affect the brain and spinal cord, which can lead to such conditions as partial paralysis and an underdeveloped skull.

In the study, women with the lowest B12 levels had five times the risk of having a child with the defect when compared to women with the highest B12 levels. The vitamin is mainly found in meat, cheese and milk.

Dr. James L. Mills, author of the study, said women who strictly adhere to a vegetarian or vegan diet may be at a higher risk of a B12 deficiency and suggests all women should manage their B12 levels.

"Half of the women who become pregnant each year in the U.S. were not planning to become pregnant," Mills said. "Our results offer evidence that women who have adequate B12 levels before they become pregnant may further reduce the occurrence of this class of birth defects."