All About Vitamin B12

Roles of Vitamin B12


Vitamin B12 is essential for many aspects of human health.

·      Brain development

·      Neural myelination

·      Cognitive function

·      Neurological function

·      Psychological function

·      Fetal and child growth

·      Synthesis of fatty acids in myelin

·      DNA synthesis (1, 2, 3)


Sources of Vitamin B12

Vitamin B12 is naturally occurring in animal products such as seafood, meat, poultry, eggs, and milk products. (4) There is no naturally occurring vitamin B12 in plant foods, but many cereals are fortified with B12, a great option for vegans and vegetarians to help reach recommended levels. (4)


Vitamin B12 Deficiency

Vitamin B12 is crucial in the functioning of so many of the body’s essential pathways, and a deficiency is therefore an immense health problem. Approximately 15% of the world population is deficient, either through lack of ingestion, or because of a problem with absorption. (5)


A deficiency of vitamin B12 in early childhood has been associated with unfavourable health outcomes including:

·      Reduced cognitive development

·      Neural damage

·      Brain atrophy (3)


Other common symptoms of Vitamin B12 include:

·      Megaloblastic anemia

·      Fatigue and weakness

·      Constipation

·      Loss of appetite and weight loss. (4)


Vitamin B12 Supplementation

Studies have shown that supplementing with Vitamin B12 in individuals who show even a borderline deficiency may have multiple beneficial effects.


Vitamin B12 is required for the synthesis of fatty acids in myelin and, in conjunction with folate, for DNA synthesis. Adequate intake of vitamin B12 is essential for normal blood function and neurological function. 



1. Federal Register of Legislation. Australia New Zealand Food Standards Code – Schedule 4 – Nutrition, health and related claims. FSANZ [Internet]. 2017 [cited June 21 2020]. Available from: 

2. Department of Health and Ageing, National Health and Medical Research Council. Nutrient Reference Values for Australia and New Zealand.  Including Recommended Dietary Intakes. Canberra: Commonwealth of Australia; 2006.

3. Venkatramanan S, Armata IE, Strupp BJ, Finkelstein JL. Vitamin B-12 and Cognition in Children. Advances in Nutrition. 2016;7(5):879-88.

4. National Institutes of Health. Vitamin B12 Fact Sheet for Health Professionals [Internet]. 2020 [cited July 6 2020]. Available from:

5. Unal D, Çelebi F, Bildik HN, Koyuncu A, Karahan S. Vitamin B12 and haemoglobin levels may be related with ADHD symptoms: a study in Turkish children with ADHD. Psychiatry and Clinical Psychopharmacology. 2019;29(4):515-9.

6. Trautmann C, Bock A, Urbach A, Hübner CA, Engmann O. Acute vitamin B12 supplementation evokes antidepressant response and alters Ntrk-2. Neuropharmacology. 2020;171.



Brittany Darling
Tags: Vitamin B12