Mandatory folic acid fortification is becoming a reality in many Western countries to cut the incidence of birth defects. A meta-analysis has now suggested that folic acid may offer health
benefits for adults, namely reductions in the risk of stroke.

US researchers analysed data from eight randomised trials looking at the link between intake of folic acid and the risk of suffering a stroke. They found that people who regularly took a folic
acid supplement were nearly a fifth less likely to have a stroke than people who took no supplement. The protective benefits increased substantially when supplementation continued for 3 years.
Those with no family history of stroke seemed to benefit the most.

The researchers recommended that long-term studies be carried out before any dietary guidelines were made as there may be risks associated with excessive folic acid intakes, e.g. masking of
vitamin B12 deficiency.

For more information, see
Wang X et al (2007) Efficacy of folic acid supplementation in stroke prevention: a meta-analysis. The Lancet, Vol 369, issue 9576, pg 1876-82.