Common side effects
Folic acid supplements may cause some common side effects, including:
rash;
itch;
turn red;
Serious side effects
Serious side effects are mainly related to over supplementation. A major problem is that although high folate levels can correct megaloblastic anemia, a health condition caused by folate deficiency, it does not reverse the nerve damage caused by B12 deficiency.
Thus, if both are present, high folate intake sometimes masks B12 deficiency until it is too late to correct it.
In addition, excess folate may increase certain health risks, including certain cancers and cognitive impairment.

So we recommend:
Magnafolate® L-Methylfolate—maximizes the supplementation delivering a "finished" folate the body can immediately use without any kind of metabolization.
Jinkang Pharma ,the Manufacturer & Supplier of L-Methylfolate.