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

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. This recommendation 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.

14C-Cobalamin Absorption from Endogenously Labeled Chicken Eggs Assessed in Humans Using Accelerator Mass Spectrometry

“…Stool collections were homogenized in order to obtain representative samples [28]. A stool sample ≤ 350 g was placed in a 3.8 L paint can and an equivalent weight of water added.…”

“…Samples were prepared as graphite for measurement using standard procedures [29,30]. Since the carbon concentrations can vary widely, carbon concentrations of all urine samples and stool homogenates were measured at LLNL using an Exeter Analytical CE440 carbon analyzer (North Chelmsford, MA, USA) as described [28]. All 14 C AMS measurements were conducted on the 1-MV National Electrostatics Corporation (Middleton, WI) AMS system at LLNL and normalized to four identically prepared IAEA C-6 isotopic standards [28,29,31].…”

“…Since the carbon concentrations can vary widely, carbon concentrations of all urine samples and stool homogenates were measured at LLNL using an Exeter Analytical CE440 carbon analyzer (North Chelmsford, MA, USA) as described [28]. All 14 C AMS measurements were conducted on the 1-MV National Electrostatics Corporation (Middleton, WI) AMS system at LLNL and normalized to four identically prepared IAEA C-6 isotopic standards [28,29,31]. An isotopic fractionation correction of δ 13 C = −25 per mil was used for all samples and results were reported as described previously [28].…”

Flour fortification for nutritional and health improvement: A review

“…It has been reported the use of fortified flours with different vitamins to reduce nutritional deficiencies and to prevent and control various diseases. For example, rice has been fortified with vitamin A, to improve the iron status and vitamin A nutrition of populations, while maize flour has been fortified with B vitamins, contributing in the elimination of beriberi and pellagra in many countries, also vitamin B12 added as a fortifier for flour retains high bioavailability when baked in bread, which when consumed contributes in the diminution in this vitamin deficiency (Akhtar et al, 2011;Das et al, 2013;Garrod et al, 2019;Johnson et al, 2004;Peña-Rosas et al, 2014;Serdula, 2010a;WHO, 2018a), vitamin D has been used to fortified chapattis consumed by residents of private sunbeds in Romania, showing higher serum vitamin D levels and significantly increased bone density (Allen, Dangour, Chalabi, & Tedstone, 2015;Ritu & Gupta, 2015;WHO, 2016).…”

Biosynthesis of vitamin B12 by Propionibacterium freudenreichii subsp. shermanii ATCC 13673 using liquid acid protein residue of soybean as culture medium

“…2 Several studies have been developed in recent years aiming at offering alternative sources of vitamin B12 to meet the nutritional demands of these populations. [4][5][6] Food fortification is one of the alternatives to increase the nutritional value of food products and to reduce the problems caused by the lack of micronutrients, including vitamin B12. 7 Another approach that has been researched is the direct addition of microorganisms, specially lactic acid bacteria, to foods, or through the fermentation of food itself (food bioenrichment).…”