Miscarriages and birth defects could be prevented if mums-to-be take Vitamin B3, according to researchers.

The team behind the study has hailed it as a breakthrough, claiming the ramifications of the study are “likely to be huge”.

The study found taking vitamin B3 supplements while pregnant can cure molecular deficiencies which lead to pregnancy loss and health problems in newborns.

Each year 7.9 million babies are born with a defect worldwide. Baby charity Tommy’s says one in six pregnancies will end in miscarriage.

The researchers analysed the DNA of four families where the mothers had suffered multiple miscarriages or their babies were born with multiple birth defects, such as heart, kidney, vertebrae and cleft palate problems.

They found mutations in two genes that caused the child to be deficient in a vital molecule known as Nicotinamide adenine dinucleotide (NAD), which allows organs to develop normally.

Lead researcher Prof Sally Dunwoodie, from the Victor Change Institute in Sydney, replicated these mutations in mice but found they could be corrected if the pregnant mother took niacin (vitamin B3).

“You can boost your levels of NAD and completely prevent the miscarriages and birth defects. It bypasses the genetic problem,” she said.

“It’s rare that you find a cause and a prevention in the same study. And the prevention is so simple, it’s a vitamin,” she said.

Dr Katie Morris, from the University of Birmingham, said: “While exciting, this discovery cannot be translated into recommendations for pregnant women, who at most may be deficient in vitamin B3.

“The doses used in this research were 10 times the recommended daily doses for supplementation in women.”

Prof Jean Golding, from the University of Bristol, called it a “solid piece of work” but urged. caution because the study was based on the genetics of four families and mice.

Doctors recommend pregnant women in the UK take a folic acid supplement of 400mcg a day until they are 12 weeks pregnant. Women trying to conceive are also urged to take folic acid to help prevent defects such as spina bifida.

The Department of Health advises women to take a vitamin D supplement throughout pregnancy.

Multi-vitamin tablets targeted at pregnant women contain some B3, but not as big a dose as was used in the study.