This is one of the most important vitamins in the B-group. Strict vegetarians may need supplements of this vitamin.

What Vitamin B12 does:

Protects against anaemia; 
Increases energy;
 Important for growth and appetite in children;
 Improves brain functions (e.g. memory, concentration, learning, balance);
Maintains a healthy nervous system;
 Stabilises menstruation and combats postnatal depression;
 May protect against cancer

Food sources of Vitamin B12:

Liver, Kidney, Oily fish, Beef, Pork, Lamb, Cheese, Free-range eggs, Milk, Fortified cereals.

Enemies:

Sunlight

Vitamin B12 deficiency symptoms:

Smooth sore tongue
Shortness of breath
Apathy or feeling of weakness Loss of concentration
Mood swings
Anaemia Menstrual problems

Vitamin B12 deficiency high risk groups include:

Strict vegetarians

Heavy drinkers
Women on the pill

People on sleeping pills

RDA for Vitamin B12:

US RDA: 3mcg

EU RDA: 2mcg