Depressed plasma pyridoxal phosphate concentrations in adult asthmatics.


Reynolds RD, Natta CL




Am J Clin Nutr


In 15 adult patients with bronchial asthma, plasma and erythrocyte pyridoxal phosphate (PLP) concentrations were significantly lower than in 16 controls (P less than 0.0001 and P less than 0.005, respectively). Oral supplementation of seven asthmatics with 50 mg pyridoxine as pyridoxine X HC1 twice daily failed to produce a sustained elevation of PLP in either the plasma or erythrocytes. However, all subjects reported a dramatic decrease in frequency and severity of wheezing or asthmatic attacks while taking the supplement. The reasons for the failure of a uniform elevation in plasma and erythrocyte PLP concentration and for the apparent beneficial effects of pyridoxine supplementation on the asthmatic symptoms of the patients are unknown at present.