Vitamin B3 may play an important role in preventing miscarriages and birth defects

For some moms, taking vitamin B3 may help prevent miscarriages and certain birth defects, according to a study published last week in the New England Journal of Medicine.

Researchers in Sydney, Australia, analyzed the DNA of four families where mothers had experienced multiple miscarriages or had babies with serious birth defects, usually involving the heart, kidney and spine.

They found two gene mutations that caused the children to be deficient in the coenzyme nicotinamide adenine dinucleotide (NAD), which is important for energy metabolism and normal organ development.

When researchers reproduced the same gene mutations in mice, they found they could prevent birth defects and miscarriages by feeding the mice vitamin B3, also known as niacin.

“Many families are affected by multiple miscarriages and birth defects,” said Sally Dunwoodie, the study’s senior author.  “We are not claiming we will prevent all cases of birth defects, but even if we can prevent a small proportion, that is significant.”

There are a couple of ways NAD can be made: One is through the breakdown of tryptophan, which people get from their diet. The two mutated genes the authors identified are involved in turning tryptophan into NAD.

But NAD can also be made from dietary vitamin B3. If a  person has low NAD levels due to the gene mutations Dunwoodie’s team identified, taking vitamin B3 could help alleviate that.

“We never had such striking evidence before — that having high enough levels of NAD is important for preventing fetal malformations,” said Kathryn Gray, a physician in the Maternal-Fetal Medicine Division at the Brigham and Women’s Hospital in Boston, Massachusetts, who was not involved in the study.

“This is first article that gave convincing evidence to suggest that lack of NAD or NAD deficiency causes fetal malformations,” she said. 

However, there is still a long way to go.

“We don’t know how common it is for people to have low NAD levels,” said Dunwoodie. There is no research yet on the prevalence of birth defects and miscarriages that are due to NAD deficiency, she said, and scientists have not determined at what point low NAD levels begin to cause birth defects.  

“These are the things we have to research before we can work out what level of niacin we should recommend women take,” she said.

For now, Gray says pregnant women should eat a healthy, balanced diet and minimize any toxic exposures.

And, of course, take a prenatal vitamin every day.  

“Those are the most important things a woman can do,” she said.