Have had two questions in the last two days from people asking whether they can get vitamin B12 from cooked fortified foods. To answer them, I updated Vitamin B12: Are You Getting It – Vegan Sources:
Tucker et al. (2000, USA, 13) found that vitamin B12 from fortified breakfast cereals and dairy products was associated with better vitamin B12 status than was B12 intake from red meat, poultry, and fish, leading the researchers to suspect that the B12 from meat might be damaged by cooking. The B12 in animal foods tends not to be cyanocobalamin, the form used in fortified foods and that is more stable during cooking. For example, in an acid medium (pH 4-7), cyanocobalamin can withstand boiling at 120° C (1).
Even so, for people wondering whether they are destroying the B12 in their fortified foods by cooking, we do not have enough evidence to know for certain, so it is safest to make sure you rely on uncooked sources of vitamin B12.
1. Personal communication, March 6-7, 2002 with Dr. Fumio Watanabe, Kochi Women’s University, Department of Health Science, 5-15 Eikokuji-cho Kochi 780-8515 Japan.
13. Tucker KL, Rich S, Rosenberg I, Jacques P, Dallal G, Wilson PW, Selhub J.
Plasma vitamin B-12 concentrations relate to intake source in the Framingham
Offspring study. Am J Clin Nutr. 2000 Feb;71(2):514-22. | link