[Do pregnant women need supplementation of folic acid?].

Neutral tube defects (NTDs) occur at an incidence of about 0.01 per cent, and in Denmark 40-50 new cases are recorded annually. Although the metabolism of folic acid increases during pregnancy, the dietary supply is marginal. Finding in recent studies suggest that folic acid supplementation as prophylactic treatment of gravidae reduces the incidence of NTDs. Folic acid prophylaxis is already being recommended as a general policy, with treatment starting before conception.