Vitamin B12

What is vitamin B12?

Vitamin B12 (cobalamin) is the most complex of all vitamins. It plays a crucial role in nerve function, blood formation, and cell division. B12 is found almost exclusively in animal foods.

Functions

• Blood formation 2D Without B12, the body cannot produce normal red blood cells, leading to megaloblastic anaemia.
• Deficiency can cause chronic fatigue.
• DNA synthesis 2D Required for normal cell division, especially important during pregnancy.

Forms

• Cyanocobalamin 2D Synthetic form, stable and inexpensive. Must be converted in the body.
• Methylcobalamin 2D Active form, directly usable. Best choice for most people.
• Adenosylcobalamin 2D Active form used in the mitochondria.
• Hydroxocobalamin 2D Often used in injections. Long half-life.

Risk groups for deficiency

Dosage

RDI: 2.4 bcg. Sublingual tablets: 10002D5000 bcg. Vegans should take B12 supplements daily.

Swedish recommendations (National Food Agency)

The National Food Agency's recommendations for daily intake of vitamin B12:

Age group	Recommended intake
Children 22D5 years	0.8 bcg
Children 62D9 years	1.3 bcg
Adolescents 102D17 years	2.0 bcg
Adults 18+ years	2.0 bcg
Pregnant women	2.0 bcg
Breastfeeding women	2.6 bcg
Vegans (all ages)	Supplementation strongly recommended

Source: National Food Agency, NNR 2023. Vegans must take B12 supplements as the vitamin is found almost exclusively in animal foods.