Schumacher H R, Bernhart F W, György P
Am J Clin Nutr. 1975 Nov;28(11):1200-3. doi: 10.1093/ajcn/28.11.1200.
Patients with rheumatoid arthritis were found to have low plasma pyridoxal phosphate. Treatment with 50-150 mg/day of pyridoxine hydrochloride for 3 months caused a rise in pyridoxal phosphate in most cases to more than 3 times pretreatment levels. There was, however, no improvement in the clinical aspects of rheumatoid arthritis.