Women are already urged to take folic acid during the first three months of pregnancy to reduce the chance of a baby suffering neural tube defects. But data suggests folic acid cannot prevent all these conditions and some disorders appear to be unresponsive to it.
Now, a team from the research arm of Great Ormond Street Hospital is investigating whether women could take a single daily pill combining the new supplement and folic acid.
One reason why folic acid may not always work is that a genetic 'blockage' occurs affecting how it is metabolised in cells. The new supplement includes nucleotides, which are able to bypass this blockage, boosting the effect of folic acid.
Tests in mice resulted in an 85% drop in the incidence of neural tube defects. Some conditions that are currently unresponsive to folic acid were also prevented.
Nicholas Greene, professor of developmental neurobiology at the Institute of Child Health, said: "This treatment could boost the effects of folic acid and offer expectant mothers an even more reliable safeguard against relatively common defects like spina bifida."
Neural tube defects affect around one in 1000 babies in the UK every year and occur if there is a problem with the development of the nervous system. The Department of Health recommends women take 400 micrograms of folic acid (also known as vitamin B9) daily while trying to conceive and for the first 12 weeks of pregnancy.