Skip to main content
ARS Home » Pacific West Area » Davis, California » Western Human Nutrition Research Center » Obesity and Metabolism Research » Research » Publications at this Location » Publication #349003

Research Project: Novel Functions and Biomarkers for Vitamins and Minerals

Location: Obesity and Metabolism Research

Title: Vitamin B12 added as a fortificant to flour retains high bioavailability when baked in bread

Author
item Garrod, Marjorie
item Buchholz, Bruce - Lawrence Livermore National Laboratory
item Miller, Joshua - Rutgers University
item Haack, Kurt - Lawrence Livermore National Laboratory
item Green, Ralph - University Of California, Davis
item Allen, Lindsay

Submitted to: Nuclear Instruments and Methods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/25/2018
Publication Date: 6/18/2018
Citation: Garrod, M.G., Buchholz, B.A., Miller, J.W., Haack, K.W., Green, R., Allen, L.H. 2018. Vitamin B12 added as a fortificant to flour retains high bioavailability when baked in bread. Nuclear Instruments and Methods. https://doi.org/10.1016/j.nimb.2018.05.042.
DOI: https://doi.org/10.1016/j.nimb.2018.05.042

Interpretive Summary: Vitamin B12 deficiency and depletion are common across the world, especially in populations that consume low amounts of animal source foods. WHO and the Food Fortification Initiative recommend that wheat flour be fortified with vitamin B12 in regions where intake of B12 is low. The purpose of this pilot study in five participants was to determine if fortification of flour with B12 produced a bread product with intact B12 still present and to determine if healthy elderly absorb sufficient B12 from bread fortified in this manner. High-purity crystalline vitamin B12 labelled with an extremely low dose of 14C isotope, was dissolved in water and added to flour (2 µg B12 /100 g flour) in a bread maker and made into rolls with on average 31.5 nCi 14C-B12 in a total of 0.8 µg B12 per roll. The 14C isotope first appeared in plasma 4 h after ingestion of the 14C fortified bread and plasma levels returned almost to background by 72 h. Measurement of 14C in plasma verified that the dose was absorbed into the systemic circulation. The cumulative % dose recovered in urine during the next 6 days was 4.8-37.0% (mean = 20.1%). Most of the 14C label in the stool appeared by day 4, and the cumulative % dose recovered in stool was 24.5- 43.0% (mean = 31.8%). Bioavailability among the 5 participants, calculated by subtracting the sum of urinary and fecal 14C excretion from the administered dose, was 28.4-63.7% (mean = 48.0%). This study showed that when B12 is added as a fortificant to flour it survives the fermentation and baking processes, and retains ~ 50% bioavailability when fed in small doses to healthy subjects. The Recommended Dietary Allowance of B12 for adults is 2.4 µg/d and assumes that usual bioavailability of low doses of the vitamin in the crystalline form is 60%, while for the same amount in foods such as meat and fish it is 50%. Our pilot study shows that B12 added to bread as a fortificant in flour was absorbed as well as it is from endogenous food sources such as meat and fish.

Technical Abstract: Vitamin B12 deficiency and depletion are common world-wide, particularly in populations that consume low amounts of animal source foods. WHO and the Food Fortification Initiative recommend that wheat flour be fortified with vitamin B12 in regions where intake of B12 is low. The purpose of this pilot study in five participants was to determine if fortification of flour with B12 produced a bread product with intact B12 still present and to determine if healthy elderly absorb sufficient B12 from bread fortified in this manner. High-purity crystalline 14C-B12 was dissolved in water and added to flour (2 µg B12 /100 g flour) in a bread maker and made into rolls (average 1.17 kBq (31.5 nCi) 14C-B12 in a total of 0.8 µg B12 per roll). Excess 14C first appeared in plasma 4 h after ingestion of the 14C fortified bread and plasma levels returned almost to background by 72 h. Measurement of 14C in plasma verified that the dose was absorbed into the systemic circulation. The cumulative % dose recovered in urine was 4.8-37.0% (mean = 20.1%). Most of the 14C label in the stool appeared by day 4, and the cumulative % dose recovered in stool was 24.5- 43.0% (mean = 31.8%). Bioavailability among the 5 participants, calculated by subtracting the sum of urinary and fecal 14C excretion from the administered dose, was 28.4-63.7% (mean = 48.0%). This study showed that when B12 is added as a fortificant to flour it survives the fermentation and baking processes, and retains ~ 50% bioavailability when fed in small doses to healthy subjects. The Recommended Dietary Allowance of B12 for adults is 2.4 µg/d and assumes that usual bioavailability of low doses of the vitamin in the crystalline form is 60%, while for the same amount in foods such as meat and fish it is 50%. Our pilot study shows that B12 added to bread as a fortificant in flour was absorbed as well as it is from endogenous food sources such as meat and fish.