[Neurological Symptoms Associated With Vitamin Deficiency and Excess: Past and Present Findings]

Vitamin deficiencies and excesses are known to cause various types of brain or peripheral nerve injuries. Improved nutritional status and dietary patterns have led to reduced prevalence, and at least some of these conditions are rare in recent times. However, delayed diagnosis (For example, in patients with Wernicke's encephalopathy) may worsen patient prognosis even in current times. Recent studies have reported an association between cognitive function and some vitamins. In this article, we summarize past and present research focused on neurological symptoms that occur secondary to vitamin deficiencies and excesses.