What is the relationship between vitamin levels and delirium?

From the Guidelines

Vitamin deficiencies, particularly B vitamins and vitamin D, can contribute to delirium, and supplementation should be considered in patients with suspected or at-risk delirium, especially those with malnutrition or poor dietary intake. According to the most recent guideline on clinical nutrition and hydration in geriatrics 1, nutritional interventions, including vitamin supplementation, should be part of a multidisciplinary approach to prevent and treat delirium in older patients. The guideline recommends a multi-component non-pharmacological intervention that includes hydration and nutrition management to prevent delirium in older patients hospitalized for urgent surgery.

Key vitamins to consider in delirium prevention and treatment include:

• Thiamine (B1): deficiency can lead to Wernicke's encephalopathy, and supplementation of 100-300mg daily for 3-5 days, followed by 100mg daily until normal diet is established, is recommended
• B12 (cyanocobalamin): deficiency can cause neuropsychiatric symptoms, and replacement is typically 1000mcg daily for a week, then weekly for a month, then monthly
• Folate: deficiency may contribute to delirium, and replacement at 1-5mg daily may be necessary
• Vitamin D: deficiency has been associated with cognitive impairment and delirium, and replacement of 1000-2000 IU daily is recommended for most adults, as suggested by a study on vitamin D and cognition in older adults 1

Assessment of vitamin status should be part of the workup for delirium, especially in at-risk populations, and vitamin replacement should be initiated promptly when deficiency is suspected, as correcting these deficiencies can improve cognitive function and help resolve delirium.

From the Research

Vitamin Levels in Delirium

• Delirium has been linked to thiamine deficiency, with studies suggesting that thiamine plays a crucial role in cellular energy production and normal neuronal activity 2.
• Thiamine deficiency can lead to serious clinical conditions, including Wernicke's encephalopathy and Wernicke-Korsakoff syndrome, which are characterized by delirium, among other symptoms 2, 3, 4.
• Biomarkers of delirium, such as microglial activation, high cerebrospinal fluid lactate levels, and MHPG, a metabolite of norepinephrine, have been identified in patients with Wernicke-Korsakoff syndrome 3.
• Thiamine deficiency can be caused by various factors, including alcoholic and non-alcoholic factors, and can lead to distinct yet overlapping neuropsychiatric disorders, including Wernicke encephalopathy and Korsakoff psychosis 4.
• Early diagnosis and treatment of thiamine deficiency are essential to prevent the development of delirium and other symptoms associated with Wernicke-Korsakoff syndrome, and treatment should be based on the administration of thiamine at the appropriate doses 5.

Thiamine Deficiency and Delirium

• Thiamine deficiency is a common cause of delirium, particularly in patients with chronic and excessive alcohol consumption, but can also be caused by other factors 2, 5.
• Delirium is a frequent complication in patients with thiamine deficiency, and can have severe consequences, including increased risks of mortality, cognitive impairment, and dependence at discharge 6.
• The diagnosis of thiamine deficiency and delirium is often clinical, with complementary tests used to support the diagnosis and rule out other causes of similar symptoms 5.
• Treatment of thiamine deficiency and delirium should be started early, with parenteral administration of thiamine at the appropriate doses, without waiting to confirm the diagnosis 5.