Balanced B Complex: Additional Information

Studies

1. Buist RA. Drug-nutrient interactions-an overview. Intl Clin Nutr Rev 1984;4(3):114 [review].
   
   
2. Alter HJ, Zvaifler MJ, Rath CE. Interrelationship of rheumatoid arthritis, folic acid and aspirin. Blood 1971;38:405-16.
   
   Abstract: Decreased serum folate (FA) levels were detected in 71% of 51 patients with rheumatoid arthritis (RA). Of 11 patients studied more intensively, only one fulfilled the usual hematologic criteria for FA deficiency. All, however, demonstrated an abnormally rapid plasma clearance of tritium-labeled pteroylglutamic acid (³HPGA). "Binding" of ³HPGA was evaluated by dialysis to apparent equilibrium and found to be significantly reduced in the sera of patients with RA. Common to all these patients was the ingestion of aspirin (ASA). Four RA patients not taking ASA had normal ³HPGA "binding". The ³HPGA "binding" of RA sera decreased as these patients were given increased ASA dosage and vice versa. The in vitro addition of ASA to normal sera reduced "binding" to the level detected in RA sera. Progressive increases in ASA resulted in progressive decreases in "binding". Aspirin given to three normal subjects reduced ³HPGA "binding" in all and serum FA in two. Precedents for ASA-induced structural change in binding proteins and for the relation between decreased binding and lowered serum levels are discussed. It is suggested that the low serum FA concentration and rapid plasma clearance of ³HPGA in RA might reflect ASA-induced alterations of FA binding, resulting in a redistribution rather than deficiency of this vitamin.
   
   
3. Morgan SL et al. The effect of folic acid supplementation on the toxicity of low-dose methotrexate in patients with rheumatoid arthritis. Arthritis & Rheumatism 1990; 33(1): 9-18.
   
   Abstract: Thirty-two patients with rheumatoid arthritis completed a 24-week, placebo-controlled, double-blind trial of folic acid (FA) supplementation during low-dose methotrexate (MTX) therapy. Administration of the daily FA supplement significantly lowered toxicity scores without affecting efficacy, as measured by joint counts, joint indices, and patient and physician evaluation of disease activity. Fifteen patients experienced some sort of toxicity; 67% were in the placebo group, and 33% were in the FA supplement group. Four patients in the placebo group had toxicity levels serious enough to require discontinuation of the MTX, while no patients in the FA supplement group discontinued MTX because of toxicity. Low-normal initial plasma and red blood cell folate levels were predictive of future toxicity with MTX therapy. We conclude that a daily supplement of 1 mg of FA during low-dose MTX therapy (median dose 7.5 mg/week [16.4 moles]) is useful in lessening toxicity without altering efficacy during the first 6 months of treatment.