Periconceptional use of folic acid reduces the risk of neural tube defects considerably. In Switzerland, implementation of these findings could be improved through fortification of a staple food with folic acid. The present paper reviews possible hazards associated with high intake of folic acid in the general population. Among the potential safety issues are interaction between folic acid and zinc, interaction between folic acid and drugs (phenytoin, methotrexate etc.) and hypersensitivity to folic acid. Of main concern are adverse effects of folic acid in cobalamin deficiency. Solutions are discussed.