Folicum 5 mg 20 tablets:

Warnings and precautions: 

• High levels of folic acid may mask a vitamin B12 deficiency, so talk to your doctor before taking folic acid. Folic acid supplements are not suitable for people with megaloblastic anemia who are deficient in vitamin B12.

 side effects:

You're likely to encounter these includerarely (and more likely at higher doses):

•  Nausea, abdominal pain, skin reactions, sleep problems, loss of appetite, or seizures.