Vitamin B12

Our vitamin B12 or cobalamin is one of the eight group B vitamins. Its name (cobalamin)
refers to its cobalt content, which is unique among vitamins. Dose: 5.5 µg
(0.005 mg)/day

Scientific evidence

Its absorption into the body requires the presence of hydrochloric acid and combination with a substance produced by the stomach (the intrinsic factor). It is then stored by the liver, pancreas, heart and brain. In view of its storage, a vitamin B12 deficiency can only appear after a certain period and in specific circumstances. It is seen most often in people with a vegan diet, those with chronic intestinal diseases, people who have undergone bariatric surgery (malabsorption problem), in the event of pernicious anaemia (an immune disease) or in the elderly due to reduced intestinal absorption.

A deficiency can produce different symptoms, such as anaemia, pins and needles in the hands and feet, constipation interspersed with diarrhoea, or weight loss. An insufficient intake causes anaemia, mood problems and, among the elderly, reasoning and memory problems. Vitamin B12 does not seem to present any risks, even at high doses. Very high doses may aggravate acne, so care should be taken by teenagers.

The daily recommended dose for women is 0.4 μg/day. However, it should be increased to 0.45 μg/day in pregnant women and 0.5 μg/day during breastfeeding.

Good for

Nervous system health and energy

Found in

Offal, meat, poultry, fish and seafood, dairy products and eggs.


Vitamin B12 is a water-soluble vitamin stored mainly in the liver. Vitamin B12 is eliminated through the bile, unlike the other water-soluble vitamins, which are eliminated via the urine.

It helps:

  • to metabolise energy normally
  • with the normal functioning of the nervous system
  • with normal homocysteine metabolism
  • with normal mental functions
  • in the formation of red blood cells
  • with the functioning of the immune system
  • to reduce fatigue
  • with cell division

Science in numbers

Alternative name

The red vitamin

Number of studies


Discovered in