Pyridoxine

Vitamin B6/Nutrient Depletion:

  • Amino acidsAmino acids: In humans, vitamin B6 decreased plasma levels of the amino acids tyrosine and methionine during endurance exercise (111).
  • AntiasthmaticsAntiasthmatics: Theophylline, a prescription drug used to help manage asthma, has been shown to lower pyridoxine levels (79; 80).
  • AntibioticsAntibiotics: According to secondary sources, destruction of gastrointestinal flora may reduce the production of vitamin B6.
  • CycloserineCycloserine: Cycloserine, an antibiotic prescribed for tuberculosis, may affect the metabolism of pyridoxine (88).
  • DialysisDialysis: In human research, dialysis decreased serum levels of vitamin B6 by 28-48% depending on the dialyzer used (89).
  • Erythropoietin stimulating agentsErythropoietin stimulating agents: In human research, vitamin B6 status in hemodialysis users was reduced with erythropoietin-stimulating agents and ion exchange phosphate-binding resins; consequently, supplementation is recommended (89).
  • FurosemideFurosemide: In humans, furosemide increased urinary excretion of vitamin B6 (90).
  • GlucoseGlucose: In human research, 100mg of pyridoxine daily improved glucose metabolism in gestational diabetes (32; 33).
  • Hormonal agentsHormonal agents: The need for vitamin B6 supplementation in women taking birth control pills lacks scientific proof, although some studies show decreased pyridoxine levels in these women (95). In a review of oral contraceptives, the authors reported a decrease in serum pyridoxal 5'-phosphate concentrations, indicating decreased stores of vitamin B6 in women on low-dose oral contraceptives and possible vitamin B6 inadequacy during pregnancy (96).
  • HydrazinesHydrazines: Pyridoxal-5-phosphate plasma concentrations were depressed in children receiving tuberculosis chemotherapy including isoniazid (97). Based on a case report, pyridoxine is suggested following isoniazid overdose (98). Hydralazine (Apresoline?) may increase pyridoxine requirements (99). Phenelzine may increase pyridoxine requirements (100).
  • Ion exchange phosphate binding resinsIon exchange phosphate binding resins: In human research, vitamin B6 status in hemodialysis users was reduced with erythropoietin-stimulating agents and ion exchange phosphate-binding resins; consequently, supplementation is recommended (89).
  • LipidsLipids: In humans, vitamin B6 decreased plasma levels of free fatty acids during endurance exercise (111).
  • Parkinson's agentsParkinson's agents: Pyridoxine enhances the metabolism of levodopa, reducing its antiparkinsonism effects. However, the use of carbidopa and levodopa (Sinemet?) may avoid this interaction, as carbidopa may reduce pyridoxine levels (34; 35).
  • Penicillamine (Cuprimine?, Depen?)Penicillamine (Cuprimine?, Depen?): According to secondary sources, penicillamine may reduce plasma levels of vitamin B6.