Vitamin B12 (Cyanocobalamin, Cobalamin)
Vitamin B12 is a water-soluble vitamin that plays an essential role in many processes in the body. It is required for:
- cell replication, particularly red blood cells
- converting food into energy
- maintaining proper functioning of the nerve cells
- maintaining proper production of the genetic material in cells
Vitamin B12 deficiency is rare in younger people, but not unusual in older people and Vegans.
Our bodies cannot produce Vitamin B12
Vitamin B12 originates from bacteria, fungi and algae and is present is almost all animal tissue, but plants contain very little or none (this is why Vegans are at risk). Vitamin B12 is the only vitamin that can be stored in large amounts in the body, mostly in the liver.
Processing, cooking in water, defrosting and even long storage will remove Vitamin B12 from foods
Vitamin B12 occurs in low concentrations in many natural foods, but is quite easily lost. Foods that are a good source of Vitamin B12 include: meat (especially liver), fish and shellfish, poultry, eggs, milk, and milk products.
Your lifestyle may increase the risk of deficiency
Aside from a poor diet, deficiencies can occur due to:
- alcohol intake
- heavy exercise
- high stress
Whilst Vitamin B12 deficiency is rare in younger people, even a moderate deficit has health consequences. The symptoms of mild deficiency are similar for all B Group vitamins:
- energy production is reduced which can cause tiredness, irritability, fatigue, and apathy.
- nervous system symptoms such as muscle weakness, cramps and numbness.
In addition, more severe Vitamin B12 deficiency causes a type of anaemia that does not respond to iron supplements.
|Age||Estimated Average Requirements (EAR)||Recommended Daily Intake (RDI)|
|Women||all||2.0 mcg/day||2.4 mcg/day|
|Men||all||2.0 mcg/day||2.4 mcg/day|
|Children||14-18 yr||2.0 mcg/day||2.4 mcg/day|
|Children||9-13 yr||1.5 mcg/day||1.8 mcg/day|
|Children||4-8 yr||1.0 mcg/day||1.2 mcg/day|
|Children||1-3 yr||0.7 mcg/day||0.9 mcg/day|
* Source: Nutrient Reference Values for Australia and New Zealand. National health and Medical Research Council
There are insufficient data to allow setting of a maximum recommended dose.
There is no evidence that the current levels of intake from foods and supplements represent a health risk. No adverse effects have been associated with excess Vitamin B12 intake from food or supplements in healthy individuals.