Effect of different folic acid doses on methotrexate-related toxicity and its association with erythrocyte methotrexate-polyglutamates in patients with rheumatic diseases: a single-center exploratory randomized controlled trial

Study limitation reported by the research below: “A small number of non-RA rheumatic disease patients were included, so disease heterogeneity may have influenced results in ways not fully assessable given the small sample.”