Vitamin B6 is a water-soluble nutrient. Orally, pyridoxine is used most commonly for treating primary homocystinuria, hyperhomocysteinemia, Alzheimer’s disease, and preventing neuritis associated with isoniazid or penicillamine. Pyridoxine is also used orally for boosting immunity, muscle cramps, protection against cancer, diuresis, conjunctivitis, cystitis, primary hyperoxaluria, preventing kidney stones, carpal tunnel syndrome (CTS), night leg cramps, arthritis, and allergies. It is used for attention deficit-hyperactivity disorder (ADHD), Down syndrome, migraine headaches, asthma, pyridoxine-responsive sideroblastic anemia, sickle cell anemia, preventing anemia due to pyridoxine deficiency, xanthurenicaciduria, primary cystathioninuria, acne, various skin conditions, stimulating appetite, hyperlipidemia, heart disease, radiation sickness, and to improve dream recall. Pyridoxine is also used orally for dizziness, motion sickness, psychosis, autism, hyperkinesis, acute chorea, chronic progressive hereditary chorea, tardive dyskinesia, absence (petit mal) seizures, febrile convulsions, gyrate atrophy of the choroid and retina, diabetes, diabetic neuropathy, age-related macular degeneration (AMD), alcohol intoxication, preventing leukopenia secondary to mitomycin, reversing procarbazine neurotoxicity, preventing seizures associated with cycloserine, fluorouracil-induced erythrodysesthesia, and acute hydrazine toxicity. It is also used orally to decrease the rate of restenosis after coronary angioplasty, inflammatory bowel disease (IBD), and for Lyme disease.