Exceptions
High parenteral doses of vitamin B6 are used to treat isoniazid overdose with no adverse effects found, although a preservative in parenteral vitamin B6 may cause transient worsening of metabolic acidosis. High doses of vitamin B6 are used to treat gyromitra mushroom (false morel) poisoning, hydrazine exposure and homocystinuria Doses of 50 mg to 100 mg per day may also be used to treat pyridoxine deficient seizures and when patients are taking other medications that reduce vitamin B6. Daily doses of 10 mg to 50 mg are recommended for patients undergoing hemodialysis.Outside of rare medical conditions, placebo-controlled studies have generally failed to show benefits of high doses of vitamin B6. Reviews of supplementing with vitamin B6 have not found it to be effective at reducing swelling, reducing stress, producing energy, preventing neurotoxicity, or treating asthma. A

Diagnosis
The clinical hallmark of megavitamin-B6 syndrome is ataxia due to sensory polyneuropathy. Blood tests are performed to rule out other causes and to confirm an elevated level of vitamin B6 with an absence of hypophosphatasia. Examination does not typically show signs of a motor deficit, dysfunction of the autonomic nervous system or impairment of the central nervous system, although in severe cases motor and autonomic imparement can occur. When examined, patients typically have diminished reflexes (hyporeflexia), such as a diminished response when performing an ankle jerk reflex test. Nerve conduction studies typically show normal motor conduction but decrease in large sensory wave amplitude in the arms and legs. Needle electromyography studies generally reveal no signs of denervation.
There is growing consensus in the pediatric community that this disorder should be renamed "medical abuse" to highlight the harm caused by the deception and to make it less likely that the sufferer can use a psychiatric defense when harm is done. Diagnosis
Due to the behaviors involved, diagnosing factitious disorder is very difficult. If the healthcare provider finds no physical reason for the symptoms, they may refer the person to a psychiatrist or psychologist (mental health professionals who are specially trained to diagnose and treat mental illnesses). Psychiatrists and psychologists use thorough history, physical examinations, laboratory tests, imagery, and psychological testing to evaluate a person for physical and mental conditions. Once the persons history has been thoroughly evaluated, diagnosing factitious disorder imposed on self requires a clinical assessment. Clinicians should be aware that those presenting with symptoms (or persons reporting for that person) may exaggerate, and caution should be taken to ensure there is evidence for a diagnosis. Lab tests may be required, including complete blood count (CBC), urine toxicology, drug levels from blood, cultures, coagulation tests, assays for thyroid function, or DNA typing. In some cases CT scan, magnetic resonance imaging, psychological testing, electroencephalography, or electrocardiography may also be employed.