Prenatal Vitamin B12 deficiency raises risk of birth defect

Font size: Decrease font Enlarge font

A new study suggests that women should make sure they have enough vitamin B12 in their blood before getting pregnant because vitamin B12 deficiency dramatically increases risk of birth defect in their babies.

March 2, 2009 ( -- A new study suggests that women should make sure they have enough vitamin B12 in their blood before getting pregnant, as a vitamin B12 deficiency dramatically increases risk of a birth defect of the brain and spinal cord in their babies.

The study in the journal Pediatrics showed Irish women whose vitamin B12 was in the lowest quartile were five times more likely to have a baby with a neural tube defect than those who had the highest levels.

For the study, Dr. James Mills of the U.S. National Institutes of Health and colleagues looked at data from 1,200 women in Ireland whose blood was tested during early pregnancy to determine vitamin B12 levels.

Folic acid deficiency has been known to be a risk factor for birth defects. But vitamin B12 deficiency is not as well known a risk factor.

The study suggested that women need to maintain vitamin B12 levels above 300 nanograms per liter before becoming pregnant.

Vitamin B12 is found in meat, dairy, eggs, fish, shellfish, and fortified foods, and it is not present in plant foods. For those who use a vegan or vegetarian diet, vitamin B12 supplements are needed.

In response to the study, the Physicians Committee for Responsible Medicine issued a statement to emphasize that women do not have to eat animal-derived foods to have a healthy pregnancy.

The PCRM cited the American Dietetic Association as stating "well-planned vegan and other types of vegetarian diets are appropriate for all stages of the life cycle, including during pregnancy, lactation, infancy, childhood, and adolescence."

"Women who follow vegan diets not only have healthy pregnancies, they are often healthier than moms who consume meat," Susan Levin, M.S., R.D., staff dietitian with PCRM said in the statement. 

"By eating a variety of fruits, vegetables, and other healthful vegetarian foods, and including breakfast cereals or other foods fortified with vitamin B12, mothers and their children can obtain all the nutrients they need to thrive."

Women who have an intestinal disorder called inflammatory bowel disease, a disorder that prevents vitamin B12 from being adsorbed, should pay attention to their needs for vitamin B12.

By Sue Mueller, and edited by Heather Kelley.

(Send your news to, is part of the ™ news and information network)