Vitamin B12 Added as a Fortificant to Flour Retains High Bioavailability when Baked in Bread

Recent Advances in Dietary Sources, Health Benefits, Emerging Encapsulation Methods, Food Fortification, and New Sensor-Based Monitoring of Vitamin B12: A Critical Review

In this overview, the latest achievements in dietary origins, absorption mechanism, bioavailability assay, health advantages, cutting-edge encapsulation techniques, fortification approaches, and innovative highly sensitive sensor-based detection methods of vitamin B12 (VB12) were addressed. The cobalt-centered vitamin B is mainly found in animal products, posing challenges for strict vegetarians and vegans. Its bioavailability is highly influenced by intrinsic factor, absorption in the ileum, and liver reabsorption. VB12 mainly contributes to blood cell synthesis, cognitive function, and cardiovascular health, and potentially reduces anemia and optic neuropathy. Microencapsulation techniques improve the stability and controlled release of VB12. Co-microencapsulation of VB12 with other vitamins and bioactive compounds enhances bioavailability and controlled release, providing versatile initiatives for improving bio-functionality. Nanotechnology, including nanovesicles, nanoemulsions, and nanoparticles can enhance the delivery, stability, and bioavailability of VB12 in diverse applications, ranging from antimicrobial agents to skincare and oral insulin delivery. Staple food fortification with encapsulated and free VB12 emerges as a prominent strategy to combat deficiency and promote nutritional value. Biosensing technologies, such as electrochemical and optical biosensors, offer rapid, portable, and sensitive VB12 assessment. Carbon dot-based fluorescent nanosensors, nanocluster-based fluorescent probes, and electrochemical sensors show promise for precise detection, especially in pharmaceutical and biomedical applications.

Comparative bioavailability of vitamins in human foods sourced from animals and plants

Vitamins are essential components of enzyme systems involved in normal growth and function. The quantitative estimation of the proportion of dietary vitamins, that is in a form available for utilization by the human body, is limited and fragmentary. This review provides the current state of knowledge on the bioavailability of thirteen vitamins and choline, to evaluate whether there are differences in vitamin bioavailability when human foods are sourced from animals or plants. The bioavailability of naturally occurring choline, vitamin D, vitamin E, and vitamin K in food awaits further studies. Animal-sourced foods are the almost exclusive natural sources of dietary vitamin B-12 (65% bioavailable) and preformed vitamin A retinol (74% bioavailable), and contain highly bioavailable biotin (89%), folate (67%), niacin (67%), pantothenic acid (80%), riboflavin (61%), thiamin (82%), and vitamin B-6 (83%). Plant-based foods are the main natural sources of vitamin C (76% bioavailable), provitamin A carotenoid β-carotene (15.6% bioavailable), riboflavin (65% bioavailable), thiamin (81% bioavailable), and vitamin K (16.5% bioavailable). The overview of studies showed that in general, vitamins in foods originating from animals are more bioavailable than vitamins in foods sourced from plants.

Vitamin B12 deficiency

Of the water-soluble vitamins, vitamin B12 (B12) has the lowest daily requirement. It also has several unique properties including a complex pathway for its absorption and assimilation requiring intact gastric and terminal small intestinal function, an enterohepatic pathway, and several dedicated binding proteins and chaperons. The many causes of B12 deficiency include malabsorption and defects in cellular delivery and uptake, as well as limited dietary intake. B12 is required as a cofactor for only two reactions in humans, the cytosolic methionine synthase reaction and the mitochondrial methymalonyl CoA mutase reaction. Disruption of either of these reactions gives rise to B12 deficiency. Although more common with advancing age, because of the higher prevalence of malabsorptive disorders in the elderly, B12 deficiency is widely distributed across all age groups particularly where food insecurity occurs. The consequences and severity of B12 deficiency are variable depending on the degree of deficiency and its duration. Major organ systems affected include the blood, bone marrow and nervous system. Megaloblastic anemia results from a defect in thymidine and therefore DNA synthesis in rapidly dividing cells. Nervous system involvement is varied, some of which results from defective myelin synthesis and repair. Cognitive impairment and psychosis may also occur. Diagnosis of B12 deficiency rests on clinical suspicion followed by laboratory testing, which consists of a panel of tests, that together provide clinically reliable predictive indices. B12 metabolism and deficiency is closely intertwined with folate, another B-vitamin. This chapter explores the various aspects of a unique and fascinating micronutrient.

Vitamin d-fortified bread: Systematic review of fortification approaches and clinical studies

Vitamin d-fortified bread has been proposed as a strategy to increase the average daily intake and serum status of this nutrient. This review aimed to bring together the different types of scientific articles on vitamin d-fortified bread. The databases used for the research were PUBMED, WEB of SCIENCE and SCOPUS; all original indexed studies written in English, published between January 2000 and March 2021, were considered. Three important points were identified: i) theoretical models of fortification; ii) stability, bioaccessibility, and bioavailability studies of vitamin d-fortified breads; and iii) clinical effects of vitamin d-fortified breads. This review showed that vitamin d-fortified bread is a promising vehicle for fortification strategy effects, leading to increased serum concentrations of 25(OH)D and decreased parathyroid hormone. However, further studies are needed to elucidate the effects and effectiveness of this fortification strategy in the prevention/treatment of vitamin D deficiency.

Vitamin B12 (Cobalamin) and Micronutrient Fortification in Food Crops Using Nanoparticle Technology

It is necessary to develop a resilient food supply that will withstand unexpected future shocks and deliver the required amounts of nutrients to consumers. By increasing the sustainability of food and agriculture, the food system will be able to handle challenges such as climate change, declining agricultural resources, growing population/urbanization, pandemics, and recessions/shortages. Micronutrient deficiency, otherwise called hidden hunger, is one of the major malnutrition consequences worldwide, particularly in middle- or low- income countries. Unlike essential mineral or nutrient compounds, micronutrients could be less of a priority due to their small levels of requirement. However, insufficient micronutrients caused critical adverse health symptoms and are excessively vital for young children's development. Therefore, there have been numerous attempts to enhance minerals and nutrients in food crops, including biofortification, food fortification, and supplementation. Based on several interventions involving micronutrients, modern technology, such as nanotechnology, can be applied to enhance sustainability and to reduce the food system's environmental impact. Previous studies have addressed various strategies or interventions to mitigate major micronutrient deficiency including iron, iodine, zinc, and vitamin A. Comparably small amounts of studies have addressed vitamin B12 deficiency and its fortification in food crops. Vitamin B12 deficiency causes serious adverse health effects, including in the nervous or blood systems, and occurs along with other micronutrient deficiencies, such as folate, iron, and zinc, worldwide, particularly in middle- and low-income countries. Mitigation for B12 deficiency has mainly focused on developing pharmacological and medical treatments such as vitamin B12 serum or supplements. Further studies are required to undertake a sustainable approach to fortify vitamin B12 in plant-based food sources for public health worldwide. This review paper highlights nanoparticle application as a promising technology for enhancing vitamin B12 without conventional genetic modification requirements. The nanoparticle can efficiently deliver the mineral/nutrient using coating techniques to targeted sites into the plant. This is mainly because nanoparticles have better solubility and permeability due to their nano size with high surface exposure. Vitamin B12-coated nanoparticles would be absorbed, translocated, and accumulated by the plant and eventually enhance the bioavailability in food crops. Furthermore, by reducing adverse environmental effects, such as leaching issues that mainly occur with conventional fertilizer usage, it would be possible to develop more sustainable food fortification.

Efficacy of B12 Fortified Nutrient Bar and Yogurt in Improving Plasma B12 Concentrations-Results From 2 Double-Blind Randomized Placebo Controlled Trials

BACKGROUND

Dietary vitamin B₁₂ (B₁₂) deficiency is common in Indians. Long-term compliance to tablet supplementation is poor in asymptomatic individuals.

OBJECTIVE

To study efficacy of B₁₂ fortified nutrient bar and yogurt in improving plasma B₁₂ concentrations in children and adults.

METHODS

Two double-blind, placebo-controlled directly observed therapy randomized controlled trials were conducted for 120 days: (1) Healthy children (10-13 years) were fed nutrient bar fortified with B₁₂ (2 μg), multiple micronutrients B₁₂ (1.8 μg) or placebo. (2) Healthy adults (18-50 years) were fed yogurt fortified with B₁₂ (2 μg) or Propionibacterium (1 × 10⁸ cfu/g) or placebo. B₁₂, folate, homocysteine, and hemoglobin concentrations were measured before and post intervention.

RESULTS

We randomized 164 children and 118 adults; adherence was 96% and 82%, respectively. In children, B₁₂ fortified bars increased B₁₂ concentrations significantly above baseline (B₁₂ alone +91 pmol/L, B₁₂+ multiple micronutrients +82 pmol/L) compared to placebo. In adults, B₁₂ fortified yogurt increased B₁₂ significantly (+38 pmol/L) but Propionibacterium and placebo did not. In both trials, homocysteine fell significantly with B₁₂ supplementation. Rise of B₁₂ and fall of homocysteine were influenced by dose of B₁₂ and folic acid. There was no significant difference in change of anthropometry and hemoglobin between groups.

CONCLUSIONS

B₁₂ fortified foods are effective in improving B₁₂ status in Indian children and adults. They could be used to improve B₁₂ status in the national programs for children, adolescents, and women of reproductive age. They could also be used as over-the-counter products.

Measuring vitamin B-12 bioavailability with [13C]-cyanocobalamin in humans

BACKGROUND

Vitamin B-12 deficiency is widespread in many parts of the world, affecting all age groups and increasing with age. It is primarily due to a low intake of animal source foods or malabsorption. The measurement of bioavailability of vitamin B-12 is etiologically important in deficiency but is limited due to the use of radioactive isotopes like [57Co]- or [14C]-cyanocobalamin.

OBJECTIVES

The aim of this study was to measure the bioavailability of [13C]-cyanocobalamin in humans and to assess the effect of parenteral replenishment of vitamin B-12 on the bioavailability.

METHODS

We synthesized a stable isotope-labeled vitamin B-12, [13C]-cyanocobalamin, using Salmonella enterica by providing [13C2]-ethanolamine as a sole carbon source. After purification and mass spectrometry-based characterization, its oral bioavailability was measured in the fasted state with high and low oral doses, before and after parenteral replenishment of vitamin B-12 stores, from the kinetics of its plasma appearance in a 2-compartment model.

RESULTS

[13C]-cyanocobalamin was completely decyanated to [13C]-methylcobalamin describing metabolic utilization, and its plasma appearance showed early and late absorption phases. At a low dose of 2.3 µg, the mean bioavailability was 46.2 ± 12.8 (%, mean ± SD, n = 11). At a higher dose of 18.3 µg, the mean bioavailability was 7.6 ± 1.7 (%, mean ± SD, n = 4). Parenteral replenishment of the vitamin B-12 store in deficient individuals prior to the measurement resulted in a 1.9-fold increase in bioavailability.

CONCLUSIONS

Vitamin B-12 bioavailability is dose dependent and at a low dose that approximates the normal daily requirement (46%). The stable isotope method described here could be used to define the etiology of deficiency and to inform the dietary requirement in different physiologic states as well as the dose required for supplementation and food fortification. This trial was registered at the Clinical Trials Registry of India as CTRI/2018/04/012957.

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

Vitamin B12 deficiency still persists, mainly caused by low intake of animal food products affecting vegetarians, vegans, and populations of underdeveloped countries. In this study, we investigate the biosynthesis of vitamin B12 by potential probiotic bacterium using an agroindustry residue, the liquid acid protein residue of soybean (LAPRS), as a low-cost, animal derivate-free alternative culture medium. Cultures of Propionibacterium freudenreichii subsp. shermanii ATCC 13673 growing in LAPRS for vitamin B12 biosynthesis were studied using the Plackett-Burman experimental approach, followed by a central composite design 2² to optimize the concentration of significant variables. We also performed a proteolytic treatment of LAPRS and evaluated the optimized-hydrolyzed medium influence on the microbial growth and metabolism in shaker flask and bioreactor experiments. In this all-plant source medium, P. freudenreichii subsp. shermanii produced high concentrations of cells and high amounts of vitamin B12 (0.6 mg/g cells) after process optimization. These results suggest the possibility of producing vitamin B12 by a potential probiotic bacterium in a very cheap, animal derivate-free medium to address the needs of specific population groups, at the same time reducing the production costs of this essential vitamin.

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

Traditionally, the bioavailability of vitamin B-12 (B12) from in vivo labeled foods was determined by labeling the vitamin with radiocobalt (⁵⁷Co, ⁵⁸Co or ⁶⁰Co). This required use of penetrating radioactivity and sometimes used higher doses of B12 than the physiological limit of B12 absorption. The aim of this study was to determine the bioavailability and absorbed B12 from chicken eggs endogenously labeled with ¹⁴C-B12 using accelerator mass spectrometry (AMS). ¹⁴C-B12 was injected intramuscularly into hens to produce eggs enriched in vivo with the ¹⁴C labeled vitamin. The eggs, which provided 1.4 to 2.6 μg of B12 (~1.1 kBq) per serving, were scrambled, cooked and fed to 10 human volunteers. Baseline and post-ingestion blood, urine and stool samples were collected over a one-week period and assessed for ¹⁴C-B12 content using AMS. Bioavailability ranged from 13.2 to 57.7% (mean 30.2 ± 16.4%). Difference among subjects was explained by dose of B12, with percent bioavailability from 2.6 μg only half that from 1.4 μg. The total amount of B12 absorbed was limited to 0.5–0.8 μg (mean 0.55 ± 0.19 μg B12) and was relatively unaffected by the amount consumed. The use of ¹⁴C-B12 offers the only currently available method for quantifying B12 absorption in humans, including food cobalamin absorption. An egg is confirmed as a good source of B12, supplying approximately 20% of the average adult daily requirement (RDA for adults = 2.4 μg/day).