B12 Benefits While Pregnant

Many pregnant and nursing mothers don't know that a vitamin B12 deficiency can have serious and lasting effects on your baby. Here's why and what to do about it.

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Photo: Maya Kruchankova/Shutterstock

If you are pregnant, or trying to conceive, you know that taking folic acid is essential for the healthy development of your baby. But according to the World Health Organization, vitamin B12 is just as important in preventing neural tube and other neurological defects in infants and unfortunately as many as 1 in 20 adults is deficient in this essential vitamin.

Vitamin B12 is important because "it helps keep the body's nerve and blood cells healthy and helps make DNA, the genetic material in all cells," explains Peter Shaw, M.D., chief medical officer of pharmaceutical company Emisphere, which manufactures B12 supplements.

"A deficiency is associated with increased risk for several adverse pregnancy outcomes for both mother and fetus. These risks include neural tube defects, intrauterine growth retardation, preeclampsia and early miscarriage," he says. Even more frighteningly, the neurological and developmental delays in babies that can be caused by a deficiency are irreversible.

Boosting B12 While Pregnant

The National Institutes of Health recommended that pregnant and nursing moms consume 2.8 micrograms (mcg) of B12 per day. Most people get that through fortified foods and animal products like beef, liver, and clams, which are the best sources of the vitamin according to Shaw, as well as fish, meat, poultry, eggs, milk, and other dairy products.

The problem comes if you're cutting back on meat and dairy products. "Plant foods have no vitamin B12 unless they are fortified," Shaw explains, which is why the American Dietetic Association recommends supplemental vitamin B12 for vegans and lacto-ovo vegetarians during both pregnancy and lactation. Vegetarians may also consider consulting their doctor on supplementation.

Yes prenatal vitamins contain B12. But human beings are not good at absorbing this particular vitamin; in fact we only absorb 1-2 percent of a typical B complex supplement. Those who suffer from conditions like celiac or Crohn's, which affect the part of the bowel that absorbs the vitamin, or who have had bariatric surgery are also at risk of a deficiency. So also taking a B complex vitamin, containing a dose of 1000 mcg, is advisable.

Identifying a B12 Deficiency

Symptoms include weakness, tiredness, or light-headedness, rapid heartbeat and breathing, pale skin, sore tongue, easy bruising or bleeding, including bleeding gums, stomach upset, weight loss, diarrhea or constipation, according to Carlos W. Benito, M.D. M.P.H. M.H.A., director of Atlantic Maternal Fetal Medicine at Morristown Medical Center in New Jersey.

"The main causes of deficiency include vitamin B12 malabsorption from food, pernicious anemia, post-surgical malabsorption, and dietary deficiency. However, in many cases, the cause of vitamin B12 deficiency is unknown," he says. Your risk for deficiency can be assessed by your doctor based on symptoms, diet, your prior medical and surgical history, and complete blood cell count.

B12 and Breastfeeding

Babies birth through 6 months should consume 0.4 mcg of B12 daily, and 0.5 mcg from 7-12 months. The bad news? "Not much gets into breast milk," Shaw says.

That is why, according to Benito, "infants who are exclusively fed breast milk from women who consume no animal products may have very limited reserves of vitamin B12 and can develop a deficiency within months of birth." He advises lactating women who follow a strict vegetarian or vegan diet to also consult with a pediatrician regarding supplements.

If you're pregnant or breastfeeding and meat's not what's for dinner, it may be worth discussing your B12 intake with your doctor, for your and your baby's sake.

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