Micronutrient: Vitamin B12

Type of Papers: Reports completed by expert consultations and published by the World Health Organization jointly with the Food and Agriculture Organization of the United Nations (FAO).

Note: Two WHO reports were summarized together as they contain much of the same information. See references below.


Prevalence of Deficiency:

Risk Factors for Deficiency:

Biochemical Indicators:

Dietary Sources and Bioavailability:

Recommended Nutrient Intakes (µg/day): The following are the Recommended Nutrient Intakes (RNI) as defined by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization.



0-6 months


7-12 months


1-3 years


Upper Limits:

Effective Interventions:

Health Consequences of Deficiency and Benefits of Intervention:


Vitamin B12. Vitamin and mineral requirements in human nutrition. Report of a joint FAO/WHO expert consultation on human vitamin and mineral requirements, Bangkok, Thailand, 21–30 September 1998. 2nd ed. Geneva: World Health Organization, 2004:279-288.

Allen LH, De Benoist B, Dary O, Hurrell R, eds. Guidelines on food fortification with micronutrients. Geneva: World Health Organization, 2006: 64-67.