Vitamin B6 deficiency causes and neurological symptoms

Petrauskaite Ieva 1, Proseviciute Ruta 1, Sarnauskas Tomas 1

1Lithuanian University of Health Sciences, Faculty of Medicine, Kaunas, Lithuania


Vitamin B6, or pyridoxine, participates in many processes in the human organism. It catalyses various enzyme reactions, acts as an antioxidant, modulator of steroid receptors and even has an antiepileptic effect. Deficiency of this vitamin is often related to altered metabolic pathways of folate and 1-carbon, impaired DNA synthesis, reparation and methylation. Therefore, the lack of it may correlate with the development of malignant processes (i.e. colorectal cancer). People get pyridoxine from food in various forms but once it enters our body, it is converted into pyridoxal phosphate, which is the only active form of vitamin B6 and is responsible for the majority of its functions. The absorption of the vitamin occurs in the small intestine, while the excess is excreted with urine. There are many possible reasons for the deficiency of pyridoxine. As a primary lack of the vitamin is very rare, secondary deficiency is usually diagnosed. It can be caused by excessive use of alcohol or pyridoxine inactivating drugs such as isoniazid or oral contraceptives. The lack of vitamin B6 is also related to chronic kidney diseases, especially because in these cases people need to follow specific diet recommendations and the excretion of the vitamin with urine or dialysate is altered. Another reason for low pyridoxine levels can be inflammatory bowel disease which manifests with malabsorption and excessive elimination of various substances from the body. When the deficiency of vitamin B6 reaches certain levels, it usually causes neurological symptoms. The lack of pyridoxine can lead to neonatal epileptic seizures that are resistant to antiepileptic drugs. It is also observed that in older people the amount of this vitamin correlates with the memory function. Therefore, it can have an impact on the cognitive state of the patients with Alzheimer’s disease. Vitamin B6 deficiency can also cause peripheral neuropathies and hyperhomocysteinemia which can lead to ischemic processes (i.e. ischemic stroke). Treatment of the lack of vitamin B6 depends on the main disease, severity of symptoms and general health of the patient. Acute neurological symptoms, such as seizures, should be treated immediately with an intravenous vitamin B6 injection. In other cases it is important to maintain adequate levels of pyridoxine in the organism, treat the main disease and remove the cause of the deficiency if possible.

Keywords: Vitamin B6, pyridoxine, pyridoxal phosphate, deficiency, neurological symptoms.