Possible Interaction: Riboflavin and Vitamin B 6

“Plasma PLP showed a stepwise decrease across riboflavin status categories from optimal (EGRac ≤1.26) to low (EGRac 1.27-1.39) to deficient status (P = 0.001), independent of dietary vitamin B-6 intake.”

“In men, pork and beef; squid, octopus, shrimp, and clams; eggs; mushrooms; Japanese-style sweets; ice cream; …, monounsaturated fatty acid, polyunsaturated fatty acid (PUFA), n-3 PUFA, n-6 PUFA, cholesterol, vitamin D, vitamin B2, vitamin B6 , vitamin B12, niacin, pantothenic acid, magnesium, … for interaction <0.05 for all).”

“Pyridoxine 5′-phosphate oxidase is dependent on flavin mononucleotide (FMN) as a cofactor which is produced from riboflavin (vitamin B2) i.e. in this biochemical pathway, dietary vitamin B6 cannot be used without vitamin B2.”

“Besides, initial consumption of vitamin B2 was not sometimes considered, but deficiency in riboflavin caused considerable impairments of vitamin B6 and niacin metabolism.”

“Our findings suggest an interaction between the status of riboflavin and vitamin B6 at intake levels normally found among Dutch elderly people.”

“ Poor riboflavin status in patients may be restricting availability of pyridoxal phosphate (PLP) due to combined effects of enhanced PLP requirements and effects of poor riboflavin status on the synthesis of PLP by pyridoxine phosphate oxidase (PPO).”

“ Pyridoxine status of patients, but not of control subjects, was directly affected by riboflavin status as judged from significant correlations between EGRAC and both AST activity and ASTAC.”

“Riboflavin therapy was effective biochemically, subjectively, and objectively, and riboflavin and pyridoxine were even more effective when concomitantly administered.”

“The results support the suggestion that the rate of metabolism of riboflavin in the red cell controls the activity of both enzymes, and the rate of red-cell metabolism of vitamin B-6.”

“The administration of pyridoxine resulted in a significant increase in the blood levels of riboflavin and the pyridoxal fraction of vitamin B6.”

“Several investigators have now reported that pyridoxine antagonizes the beneficial effects of levodopa, 5-8 and at least one multiple vitamin preparation without pyridoxine is now available because of this.”