Considering the Case for Vitamin B 12 Fortification of Flour

Abstract

Reasons to fortify flour with vitamin B₁₂ are considered, including the high prevalence of depletion and deficiency of this vitamin that occurs in persons of all ages in resource-poor countries and in the elderly in wealthier countries, and the adverse functional consequences of poor vitamin B₁₂ status. From a global perspective, the main cause of inadequate intake and status is a low intake of animal-source foods; even lacto-ovo vegetarians have lower serum vitamin B₁₂ concentrations than omnivores, and for various reasons many populations have limited consumption of animal-source foods. Infants are vitamin B₁₂-depleted from early infancy if their mothers' vitamin B₁₂ status and intake are poor during pregnancy and lactation. Even in the United States, more than 20% of the elderly have serum vitamin B₁₂ concentrations that indicate depletion, and an additional 6% have deficiency, primarily due to gastric atrophy, which impairs the absorption of the vitamin from food but usually not from supplements or fortified foods. Although the evidence is limited, it shows that fortified flour, consumed as bread, can improve vitamin B₁₂ status. Where vitamin B₁₂ fortification is implemented, the recommendation is to add 20 μg/kg flour, assuming consumption of 75 to 100 g flour per day, to provide 75% to 100% of the Estimated Average Requirement; the amount of the vitamin that can be added is limited by its cost. The effectiveness of this level of addition for improving vitamin B₁₂ status in programs needs to be determined and monitored. In addition, further research should evaluate the bioavailability of the vitamin from fortified flour by elderly people with food cobalamin malabsorption and gastric atrophy.