Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Health & Pregnancy

Font Size

Birth Defects Linked to Low Vitamin B12

Study Shows B12 Deficiency May Raise Risk of Spina Bifida and Other Neural Tube Defects
WebMD Health News
Reviewed by Louise Chang, MD

March 2, 2009 -- Women who don't get enough vitamin B12 may have a higher risk of giving birth to a baby with a potentially disabling or fatal birth defect.

A new study shows that women with vitamin B12 deficiency in early pregnancy were up to five times more likely to have a child with neural tube defects, such as spina bifida, compared to women with high levels of vitamin B12.

"Vitamin B12 is essential for the functioning of the nervous system and for the production of red blood cells," says Duane Alexander, MD, director of the National Institute of Child Health and Human Development, which funded the study. "The results of this study suggest that women with low levels of B12 not only may risk health problems of their own, but also may increase the chance that their children may be born with a serious birth defect."

Researchers say the results suggest that women of childbearing age, women in early pregnancy, and women who hope to become pregnant should take steps to ensure their diet includes foods rich in vitamin B12 or take supplements to reduce their risk of vitamin B12 deficiency and birth defects.

Vitamin B12 is found in meat, poultry, milk, eggs, and other fortified foods. Vegans and vegetarians, and women who have intestinal disorders that prevent them from absorbing vitamin B12, are most susceptible to vitamin B12 deficiency. Vegetarian sources of vitamin B12 include fortified breakfast cereals and some fortified vegetarian "meat" products like veggie burgers.

Vitamin B 12 and Pregnancy

Neural tube defects refer to a group of birth defects that affect the brain and spinal cord. The defects include spina bifida, which can cause partial paralysis, and anencephaly, a fatal condition in which the brain and skull are severely underdeveloped.

The synthetic form of the vitamin folate, folic acid, can significantly reduce the risk of neural tube defects. With food fortification, the incidence of neural tube defects has decreased dramatically. Researchers say these results suggest it may also play a role in birth defect prevention.

In the study, published in Pediatrics, researchers compared vitamin B12 levels in blood samples taken from three groups of Irish women between 1983 and 1990 who were pregnant with or previously had a child with a neural tube defect to those in women with healthy pregnancies. The researchers took into account folate levels in their analysis.

Pregnancy Week-By-Week Newsletter

Delivered right to your inbox, get pictures and facts on
what to expect each week of your pregnancy.

Today on WebMD

hand circling date on calendar
Track your most fertile days.
woman looking at ultrasound
Week-by-week pregnancy guide.
Pretty pregnant woman timing contaction pains
The signs to watch out for.
pregnant woman in hospital
Are there ways to do it naturally?
slideshow fetal development
pregnancy first trimester warning signs
What Causes Bipolar
Woman trying on dress in store
pregnant woman
Woman looking at pregnancy test
calendar and baby buggy
dark chocolate squares