Vitamin B12 Deficiency and Dementia


Vitamin B12 Deficiency and Dementia

According to recent studies, a vitamin B12 deficiency can increase the risk of dementia. So can vitamin B12 help fight dementia as an adjuvant therapy?

Guest Page: Dementia and Mirconutrients

Dementia related diseases are often associated with low micronutrient levels, because elderly people usually eat an unbalanced diet and also are likely to suffer malabsorption, limiting their absorption capabilities of essential nutrients. So what exactly is the relationship between dementia and micronutrients – in particular with vitamin B12? How can vitamin B12 help to prevent and treat dementia?

To help answer these questions we’ve asked Dr. Birgit Schiel to comment on the topic.

Malnutrition Leads to Cognitive Deficits

Studies show that mental performance is supported by sufficient levels of micronutrients. However, as dietary behaviour changes and the body’s resorption mechanisms deteriorate, the elderly people find it increasingly difficult to obtain a sufficient micronutrients supply.

Oxidative Stress as a Factor Affecting Neurodegeneration

Micronutrients help protect nerve cells from oxidative damage and can counteract oxidative processes like atherosclerotic pathological changes, thus improving microcirculation in the brain. They also improve metabolism of homocysteine, reducing inflammation. 

Using Micronutrients to Prevent Dementia

The following nutrients are particularly important in preserving mental ability:

  • B-vitamins (i.e. folic acid, vitamin B12) improves cell energy metabolism and blood low to the brain.

  • Omega 3 fatty acids (particularly docosahexaenoic acid  – DHA) plays an important role in the functionality of the CNS.

  • Coenzyme Q10 can help protect against the damage of brain cells and aids the stabilisation of cell membranes.

  • Acetylcarnitine promotes the release of acetylcholine, is neuroprotective and may improve brain function.

  • Zinc important to prevent the loss of brain cells. Patients suffering from dementia often have reduced zinc levels.

  • Ginkgo allows better blood flow to the brain and a better memory performance.

Vitamin B12 – Deficiency Increases Risk of Dementia

A vitamin B12 deficiency can encourage cognitive decline in older age – this fact was been published in the 2011 in Neurology after studies took place.1 The results of these studies indicated that a lack of vitamin B12, which is essential for proper neuronal functioning, should be regarded as a potential risk factor in the development of dementia related diseases.

B Complex as a Treatment Option Against Cognitive Decline

‘Methylation catalysts’ such as folic acid, vitamin B12 and vitamin B6 can help prevent the atrophy of gray matter, thus preventing cognitive decline. This was discovered through a study at the University of Oxford, in which 156 patients with mild cognitive deficits took part. Each patient was given a vitamin B complex containing 800mcg folic acid, 20mg vitamin B6 and 500mcg vitamin B12. The study demonstrated that relatively simple intervention could reduce the loss of specific neurons in the medial temporal lobe.2

Methylcobalamin – Active Vitamin B12

Methylcobalamin is one form of vitamin B12 and it particularly important for cell growth in the central nervous system (CNS). Cyanocobalamin must first be metabolised in the liver into one of the active forms (5 desoxyadenosylcobalamin or methylcobalamin) before it is biologically usable. However, this requires good liver function. The neuroprotective properties of methylcobalamin can be explained through vitamin B12’s neuronal regenerative qualities and through folic acid’s homocysteine ​​reducing abilities.

Vitamin B12 and Dementia: Conclusion

In its active form (methylcobalamin), vitamin B12 offers a valid option for the prevention and treatment of dementia. Regular monitoring of vitamin B12 levels as well as associated parameters (homocysteine, folic acid and vitamin B6) may help identify a problem in good time.

About the author:

Birgit SchielDr. Birgit Schiel

Life and social coach (Focussing on health advice)
Individual diploma degree Health Sciences – Specialist subject: Pharmacy
Doctor of Natural Sciences

Scientific advisory activity at Pro Medico



  1. Vitamin B12, cognition, and brain MRI measures: a cross-sectional examination
  2. Preventing Alzheimer’s disease-related gray matter atrophy by B-vitamin treatment