I guess 5-MTHF should be much more easily absorbed. Ordinary folic acid as used in dietary supplements and vitamin-fortified foods must first be converted to bioactive 5-methyltetrahydrofolate (5-MTHF) in order to be clinically effective.
These steps require several enzymes, adequate liver and gastrointestinal function, and sufficient supplies of niacin (B3), pyridoxine (B6), riboflavin (B2), vitamin C, and zinc. Many IBDers, especially Cronnies, are deficient some of these nutrients, especially zinc.
I take folic acid in my multivite so I really, really hope the following is just speculation:
chriskresser.com/folate-vs-folic-acidHuman exposure to folic acid was non-existent until its chemical synthesis in 1943, and was introduced as a mandatory food fortification in 1998...
Excess folic acid may stimulate the growth of established neoplasms, which can eventually lead to cancer. The presence of unmetabolized folic acid in the blood is associated with decreased natural killer cytotoxicity. Since natural killer cells play a role in tumor cell destruction, this would suggest another way in which excess folic acid might promote existing premalignant and malignant lesions.