Polyneuropathy is one of the most frequent manifestations in chronic
uremia. Among the factors related to
polyneuropathy,
vitamin B6 deficiency is well known. The exact prevalence of
vitamin B6 deficiency related to
neurological manifestations has not been previously reported. We studied
vitamin B6 status, collected self-reported symptoms, and carried out full neurological examinations in 66 patients on chronic
peritoneal dialysis.
Vitamin B6 status was estimated by direct measurement of
pyridoxal phosphate. In general, symptoms related to
vitamin B6 deficiency are
peripheral neuropathies, such as
paresthesia, burning and painful
dysesthesias, and thermal sensations. These symptoms were reported and assigned one of five grade scores. Of our 66 patients, 12 patients complained at least one sensory abnormality. The levels of
vitamin B6 in the patients varied between 1.0 ng/mL and 30 ng/mL. Patients who complained of neurological symptoms owing to
vitamin B6 deficiency were significantly older than the other patients. In analyzing the symptomatic cases before and after
vitamin B6 supplementation, a significant correlation was seen between the level of
vitamin B6 and symptoms. Within one month after initiation of oral
vitamin B6 supplementations (30 mg daily), levels of
pyridoxal phosphate rose, and sensory abnormalities improved in 8 of 12 patients. When
peripheral neuropathy is suspected in elderly patients on chronic
peritoneal dialysis,
vitamin B6 deficiency should be taken into consideration as the cause. If
vitamin B6 deficiency is appropriately treated by oral supplementation, sensory abnormalities can be eliminated.