Vitamin B-6 Dependency Syndromes Treatment & Management

Updated: Oct 19, 2022
  • Author: Haritha Reddy Chelimilla, MD; Chief Editor: Jatinder Bhatia, MBBS, FAAP  more...
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Medical Care

Recommended maintenance doses of pyridoxine (vitamin B-6) have ranged from 2-300 mg/d. [1, 2] Responses to treatment have included an improvement in the intelligence quotient (IQ) score and reversal of mental retardation in patents with pyridoxine-dependent seizure (PDS), depending on the dose on pyridoxine given. The suggested mechanism of this is normalization of CSF glutamate. Some studies have also found an improvement in the quality of behavior and IQ following an increase in the dose (150-500 mg/d) of pyridoxine given to older children with PDS. [1, 28]

For patients with acute seizures pyridoxine can be administered intravenously, under EEG monitoring if available and with adequate respiratory support in case apnea occurs as an immediate treatment response. A dose of 100 mg of pyridoxine- HCl should be given intravenously with additional doses may be administered over the course of 30 min as needed for response. Clinicians should be aware of possible cardiorespiratory depressive effects of a first pyridoxine administration.

Kuo et al suggested that pyridoxine phosphate should be considered as the drug of choice in atypical cases in children who do not respond to pyridoxine. [11] This is in an attempt to reduce failure rate and further delay in seizure control because pyridoxal phosphate is the active coenzyme for more than 100 enzymes. Further research is needed.

Monitor seizure activity in patients with vitamin B-6 dependency syndrome.



Consultations include the following:

  • Neurologist

  • Metabolic physician/Geneticist

  • Eye specialist

  • Rehabilitation specialists - Dietitian, physiotherapist, speech pathologist, and occupational therapist


Diet and Activity


Oral supplementation of vitamin B-6 is essential because dietary sources cannot be manipulated to achieve such a high requirement (100 mg/d). No other nutritional support specific to PDS is indicated; however, sequelae of this disease may increase the nutritional risk. According to the Dietary Guidelines for Children and Adolescents, ensuring nutritional adequacy of the diet is essential. This includes adequate vitamin B-6 intake, which meets recommended dietary intake specific to age and sex. Children with mental retardation often cannot achieve sufficient caloric requirements through oral intake alone; thus, supplementary feeding, including enteral feeding, may be indicated. A referral to a dietitian to ensure nutritional adequacy of the diet is recommended initially and then periodically as required.

Coughlin et al reported that adjunct lysine reduction therapies are associated with significant improvements in development; however, the effectiveness of these treatments is limited if they are delayed beyond the first few months of life. A lysine-restricted diet often involves the use of low-protein foods and medical foods and should be monitored by a multidisciplinary team, including a metabolic dietitian. [29]


Physical activity has not been reported to be of special benefit in children with PDS.