To determine B12 bioavailability from 14C-B12 fortified bread in healthy subjects and in subjects with proton pump inhibitor induced achlorhydria.

Cobalamin (vitamin B12) deficiency is highly prevalent in the US and worldwide. Deficiency is most common in the elderly, with an average prevalence ≈25% over age 60 y. About 40% of older persons with low serum cobalamin have food cobalamin malabsorption (F-CM), in which gastric atrophy/achlorhydria and/or dysfunction is implicated. Because of the prevalence of deficiency in those over age 60 y, it is generally recommended that the elderly consume a higher proportion of their cobalamin from fortified foods than what is recommended for younger people. However there is considerable debate about whether crystalline cobalamin is absorbed as well by the elderly with F-CM as it is by younger people, especially if it is added as a fortificant to food. The data to be collected in this study will provide information useful to on-going deliberations concerning the future fortification of wheat flour with vitamin B12 in the United States.

Inclusion Criteria:

• good overall health
• normal absorptive capacity (controls) or with a serum B12 <300 pg/mL and a pepsinogen I level >100 μg/L (ACs).
• All subjects must be available to complete the protocol

Exclusion Criteria:

• Any chronic health disorder
• Anemia of any kind
• Renal insufficiency
• excessive alcohol consumption
• Prior GI surgery
• Use of OTC or prescription drugs that interfere with B-12 absorption or metabolism
• Use of vitamin supplements
• Pregnancy or lactation