“ Folic acid supplementation has been reported anecdotally to lessen toxicity in patients receiving methotrexate treatment [27, 28].”
“In a 6-month, double-blind, placebo-controlled trial, 7 mg of folic acid weekly (1 mg/d or 2265 nmol/d) decreased methotrexate toxicity without affecting efficacy [29].”
“The influence of the folic acid dose on methotrexate toxicity and efficacy remains controversial, and the effects of different doses of folic acid are not known [37, 38].”