Bioavailability Of Vitamin B12 Research Articles

Effect of calcium supplementation on reversing metformin-based inhibition of vitamin B12 bioavailability in healthy adults using a [13C] cyanocobalamin tracer – A pilot study

Metformin is a widely prescribed first line drug for the treatment of type 2 diabetes mellitus (DM). Studies have shown that the use of metformin is often associated with a decrease in vitamin B12 (B12) levels in patients with DM. Few studies have shown that this effect could be mitigated with calcium supplementation. In the present study, we quantified the effect of metformin, and metformin co-administered with calcium on B12 absorption using a novel stable isotope [13C] cyanocobalamin tracer. A pilot crossover study was conducted to estimate the bioavailability of B12 in healthy subjects, using [13C] cyanocobalamin as a tracer. In the study, [13C] cyanocobalamin was administered orally to the participants followed by hourly venous sampling to measure the concentration of the tracer and estimate bioavailability. This protocol was followed for three experiment days, each separated by a one month wash out period. As part of the study, all participants received the tracer alone for the control day (C), metformin 850mg along with the tracer for the metformin day (M) and metformin 850mg with calcium 500mg and the tracer for the metformin calcium day (MC). Seven participants completed all three experiment days. The mean B12 bioavailability (±SD, n=7) was 42.6±10.2% for the control day (C), 30.8±15.3% for the metformin day (M) and 46.4±8.6% for the metformin-calcium day (MC). Repeated measures ANOVA was done and the pairwise comparison showed a significant difference in the B12 bioavailability between control and metformin day (C vs M p=0.010), and between the metformin and metformin with calcium day (M vs MC p=0.003). B12 bioavailability reduced significantly from baseline (C) when metformin (M) was administered and this reduction was reversed when calcium was co-administered (MC) in healthy participants. In patients using metformin, calcium supplementation as a strategy to prevent B12 deficiency needs to be further studied.

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.

Fermented vegetables and fruits as vitamin B12 sources: An overview

There is a trend towards the consumption of plant foods, especially from the public that aims to reduce meat consumption. Plant-based food diets may have low source of vitamin B12 as plants do not produce them. A possible alternative to mitigate this is the consumption of fermented vegetables and fruits. Therefore, we aimed to provide an overview of the work being done with fermented vegetables and fruits, and show evidence that it is possible to obtain the necessary daily amount of vitamin B12 for human health and maintenance. Vitamin B12, also known as cobalamin, acts as a cofactor for the enzyme methionine synthase and methylmalonylCoA mutase in eukaryotes. The dietary reference values for adult men and women range between 2 and 4 μg/day; however, the requirement may increase depending on special recommendations. The main causes for vitamin B12 deficiency are autoimmune conditions (e.g., pernicious anaemia), malabsorption, and dietary insufficiency. One of the commonly adopted measures to deal with vitamin deficiency is supplementation. It is also possible to obtain food enriched with vitamin B12 through fermentation. Different plant materials and microorganisms can be used to produce fermented products and enhance traditional products, such as tempeh, to increase vitamin B12 concentration in the final product. The bioaccessibility and bioavailability of vitamin B12 in fermented vegetables and fruits are important factors to be considered, and demand more studies. The intake of soy fermented foods, such as tempeh, tofu, and cheonggukjang was associated with cognitive enhancement and neuroprotective effects. In addition to fermented vegetables and fruits, other non-animal sources of vitamin B12 that deserve great attention are algae and mushrooms. Since fermentation can produce considerable amounts of vitamin B12, fermented vegetables and fruits are feasible alternative sources for the intake of this vitamin.

Investigation of the potential of Glycyrrhiza glabra as a bioavailability enhancer of Vitamin B12.

Vitamin B12 deficiency is prevalent among individuals globally. Inadequate consumption of B12 rich diet and low bioavailability (due to diet based/physiological factors) are linked to the deficiency of Vitamin B12 inside the body. Bioavailability enhancers augment the bioavailability of an ingested substance (drug/nutrient) thus increasing their concentration inside the body and maximizing their therapeutic benefits. In traditional medicine, Licorice (Glycyrrhiza glabra) finds utility in the treatment of various health conditions. Thus, the present study aimed to examine the potential of ethanolic extract obtained from G. glabra roots to enhance the bioavailability of Vitamin B12. The effect of ethanolic extract of G. glabra (GgEtOH) on intestinal absorption enhancement of B12 was assessed in vitro on Caco-2 and ex-vivo everted gut sac models. The influence of extract on the pharmacokinetics of Vitamin B12 was determined in vivo in Swiss albino mice. GgEtOH significantly enhanced the permeation (Papp) of B12 by 2-5 fold in vitro (25, 50, and 100 μg/ml concentrations) and ex-vivo (250 and 500 μg/ml concentrations). The pharmacokinetic parameters of B12 such as Cmax, AUC, Tmax, etc. were also significantly elevated in vivo upon oral administration of B12 (1 mg/kg dose) in combination with GgEtOH (100 and 1,000 mg/kg dose). These preliminary findings indicate that the ethanolic extract of G. glabra is capable of enhancing the bioavailability of Vitamin B12. To the best of our knowledge, this is the first report to demonstrate herbal extract-mediated enhancement of Vitamin B12 bioavailability through in vitro, ex vivo, and in vivo assays.

A Dietitian-Led Vegan Program May Improve GlycA, and Other Novel and Traditional Cardiometabolic Risk Factors in Patients With Dyslipidemia: A Pilot Study

BackgroundSystematic inflammation and lipid profiles are two major therapeutic targets for cardiovascular diseases. The effect of a nutritionally balanced vegan diet on systematic inflammation and lipoprotein subclass awaits further examination.ObjectiveTo investigate the change in novel and traditional cardiometabolic risk factors before and after a dietitian-led vegan program, and to test the bioavailability of vitamin B12 in Taiwanese purple laver as part of a vegan diet.DesignA one-arm pilot intervention study.Participants/SettingNine patients with dyslipidemia participated in this 12-week vegan program.Main Outcome MeasuresNuclear Magnetic Resonance (NMR) detected GlycA signals (systematic inflammation) and lipoprotein subclass (atherogenicity); trimethylamine N-oxide (TMAO); and other cardiometabolic risk factors.Statistical Analyses PerformedWilcoxon signed-rank test.ResultsIn this 12-week vegan intervention emphasizing whole foods, systematic inflammation improved as indicated by a reduction in GlycA (median: −23 μmol/L, p = 0.01). LDL-c (low-density lipoprotein cholesterol) (median −24 mg/dl, p = 0.04) and LDL-p (low-density lipoprotein particles) (median −75 nmol/L, p = 0.02) both decreased significantly. VLDL (very-low-density lipoprotein) and chylomicron particles showed a decreasing trend (−23.6 nmol/L, p = 0.05). Without caloric restriction, body mass index (BMI) (−0.7 kg/m2, p = 0.03), waist circumferences (−2.0 cm, p < 0.001), HbA1c (−0.2%, p = 0.02), and (HOMA-IR) homeostatic model assessment for insulin resistance (−0.7, p = 0.04) have all improved. The change in the TMAO and vitamin B12 status as measured by holo-transcobalamin appeared to depend on baseline diets, TMAO, and vitamin B12 status.ConclusionsA dietitian-led vegan program may improve systematic inflammation and other novel and traditional cardiometabolic risk factors in high-risk individuals.

Development of vitamin B12 containing pullulan-bovine serum albumin microparticles designed dry powder inhaler: In-vitro and in-vivo study

The poor permeability and low bioavailability of vitamin B12 (vit. B12) through the mucosal lining of lungs are required substitutes. Therefore, the present work aims to develop a dry powder inhaler (DPI) of (Vit.B12) encapsulated into bovine serum albumin (BSA) followed by pullulan coated micro particles (Vit.B12-Pull-BSA) through spray drying. Briefly, pullulan was used as a mucoadhesive agent whereas BSA was used as an encapsulating agent. The obtained Vit.B12-Pull-BSA micro-particles were characterized using different in-vitro spectroscopic techniques, in vitro dissolution, mucoadhesion study, particle size analysis, etc. As a result, the surface morphology of Vit.B12-Pull-BSA micro-particles shows spherical micro-particle with circular surface morphology that can be suitable for pulmonary drug delivery. The PXRD study reveals the conversion of the crystalline nature of vitamin B12 to amorphous nature. Particle size showed 590.1 nm and zeta potential of microparticles was −27.3 mV respectively, which indicates the good stability of particles. The in-vitro assessment of Vit.B12-Pull-BSA microparticles using cascade Impactor revealed that 90.8 ± 1.1% of dry powder formulation was emitted from the device whereas 64.1 ± 6.8% of vitamin B12 loaded particles were reached at a fine stage that suggests preferential delivery of micro-particle. Male Wister rats were utilized for pharmacokinetic analysis through intratracheal administration of Vit.B12-Pull-BSA micro-particles that confirmed the increase in the permeability. Accordingly, it increases the 4.5 folds' relative bioavailability of vitamin B12. In conclusion, the Vit.B12-Pull-BSA micro-particles-based DPI offers improved permeability and bioavailability that can provide the alternative for conventional drug delivery.

B12 levels and frailty syndrome.

Vitamin B12, widely known as cobalamin, is a water-soluble vitamin crucial for human metabolism. It is synthesized only by prokaryotic organisms and since humans do not have the ability to synthesize it, they rely on its exogenous dietary intake. After its consumption, vitamin B12 undergoes a complicated procedure of absorption and assimilation and it is essential for cellular function, especially for nervous system, red blood cell production and DNA synthesis. Deficiency of vitamin B12 is considered as an important public health issue worldwide, while it is common in the elderly. Deficiency of this vitamin, as well as high levels, indicate a risk factor for morbidity with various clinical manifestations. Frailty is an age-related syndrome, which affects the elderly and is characterized by decreased function in many physiological systems, accompanied by vulnerability to stressors. A narrative non-systematic mini review of the literature was conducted and highlighted that vitamin B12 levels may have an impact on frailty and vice versa. As shown in several studies, vitamin B12 levels may be related to sarcopenia, cognitive and musculoskeletal disorders, neurological or psychiatric symptoms, which are closely linked to frailty. Furthermore, it is suggested that the extensions of frailty may affect the bioavailability of vitamin B12.

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

Vitamin B-12deficiency is widespread inmany parts of the world,affecting all age groups and increasing with age.It is primarily due to a low intake of animalsourcefoodsor 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. 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. 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, fromthe kinetics of itsplasma appearancein a 2-compartment model. [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 2.3µg,themeanbioavailability was 46.2±12.8 (%, mean±SD, n = 11). At a higher dose of 18.3µg, the mean bioavailability was 7.6±1.7 (%, mean±SD, n=4). Parenteral replenishment of the vitaminB-12 store in deficient individuals prior to the measurement resulted in a 1.9-fold increase in bioavailability. VitaminB-12 bioavailability is dose dependent and at a low dose that approximates the normal daily requirement (46%). The stable isotope method described here couldbe used to define the etiology of deficiency and to informthe dietaryrequirement in different physiologic states as well asthe doserequired forsupplementationandfood fortification. This trial was registered at the Clinical Trials Registry of India as CTRI/2018/04/012957.

Measuring Oral Vitamin B12 Bioavailability Using [13C]-cyanocobalamin in Humans

Abstract Objectives To biosynthesize a stable-isotope labeled [13C]-cyanocobalamin and to measure its bioavailability in humans. Methods Salmonella enterica was precultured in Luria-Bertani medium and single-cell colonies were grown in No carbon E medium, supplemented with [13C]-ethanolamine as a sole-carbon source along with other precursors (dicyanocobinamide and dimethylbenzimidazole) and incubated for 48 h at 30°C and centrifuged. The pellets were resuspended in methanol/sodium cyanide and incubated overnight and extracts were purified by HPLC. The peaks corresponding to standard cyanocobalamin were collected and characterized by MALDI-MS. After animal testing, healthy young subjects were orally administered with [13C]-cyanocobalamin in a protocol that included hourly blood sampling for 12 h post-dose, and daily sampling for the next 5 days, to characterize its kinetics at a higher dose than the daily requirement (∼10x, n = 4, 2 males and females) and its appearance was modeled using a two-compartment model with early and late absorption phases. The same model was applied for lower dose at daily requirement (∼2.5 μg, n = 11 males), with sampling for 12 h post-dose. In addition, the effect of co-ingested food (n = 1, male) and the effect of parenteral replenishment of existing body vitamin B12 stores by intramuscular injection of 1 mg hydroxocobalamin, (n = 3, males) on bioavailability was also studied. The appearance of tracer in plasma was quantified by Q-Exactive-Orbitrap-MS. Results Biosynthesized [13C]-cyanocobalamin was labeled with up to 7–13[C] atoms and at a daily requirement dose (∼2.5 μg), its mean bioavailability was 50.4 ± 8.2%, but this was also dependent on the existing body store of vitamin B12. Two-weeks after replenishing the body stores, bioavailability increased by 1.5-fold (from 45.6 ± 0.02% to 67.8 ± 0.06%). At a higher dose (∼20 μg), its bioavailability was 6.0 ± 1.2% but the absolute amount absorbed was similar to that with the low dose. Conclusions A novel stable isotope-based vitamin B12 bioavailability assessment is described at low and high doses. This has implications toward rationalizing dosages used in clinical supplementation and public health fortification programs. Funding Sources Department of Biotechnology, India (to SD and AVK) and by the Wellcome Trust/DBT India Alliance Margdarshi Fellowship [No. IA/M/14/1/501,681] awarded to AVK.

Vitamin B12 and its binding proteins in milk from cow and buffalo in relation to bioavailability of B12

Milk is an important source of highly bioavailable vitamin B12 (cobalamin) in human nutrition. In most animal products, vitamin B12 is strongly bound to various specific protein carriers. The 2 vitamin B12-specific proteins, predominantly transcobalamin (TC) and haptocorrin (HC), were earlier found in milk from Holstein Friesian cows and in human or sow milk, respectively. As the type of vitamin B12 binders may influence bioavailability of the vitamin, we examined vitamin B12 carriers in pooled milk specimens derived from European and Indian cow and buffalo herds. The total endogenous vitamin B12 concentration was comparable in all milk pools (≈3 nM), but the vitamin carriers varied considerably: TC + caseins in Danish cows, TC + HC in Indian cows and buffaloes, and mainly HC in Italian buffaloes. Danish cow milk contained half as much TC as vitamin B12, and the surplus vitamin was all attached via a single coordination bond to abundantly available histidine residues of casein. The specific binding proteins in Indian cow milk (TC + HC) approximately matched the molar content of vitamin B12. Milk from the 2 buffalo breeds contained more specific binders than vitamin B12, and the surplus proteins included the unsaturated TC ≈ 3 nM (Indian stock), or both TC ≈ 4 nM and HC ≈ 23 nM (Italian stock). The abundant HC of the latter sample bound nearly all endogenous vitamin B12. We tested (in vitro) the transfer of vitamin B12 from milk proteins to human carriers, involved in the intestinal uptake. The bovine TC-vitamin B12 complex rapidly dissociated at pH 2 (time of half reaction, τ1/2 < 1 min, 37°C) and was susceptible to digestion with trypsin + chymotrypsin (pH 7.5). Transfer of vitamin B12 from the precipitated bovine casein (pH 2) to human carriers proceeded with τ1/2 ≈ 7 min (37°C) and τ1/2 ≈ 35 min (20°C). Liberation of vitamin B12 from buffalo HC was hampered because of its pH stability and slow proteolysis. Nutritional availability of vitamin B12 is expected to be high in cow milk (with TC-vitamin B12 and casein-vitamin B12 complexes) but potentially constrained in buffalo milk (with HC-vitamin B12). This especially concerns the Italian buffalo milk, where a high excess of HC was found. We speculate whether the isolated stock of Italian buffalo maintained the ancestral secretion of carriers (HC ≫ vitamin B12, TC ≈ 0), whereas intensive crossbreeding of cows and buffaloes from other regions caused a change to TC ≤ vitamin B12, with low or absent HC. The substitution of HC by less sturdy carriers is apparently more beneficial to human consumers as far as vitamin B12 bioavailability is concerned.

Vitamin B12 buccoadhesive tablets: auspicious non-invasive substitute for intra muscular injection: formulation, in vitro and in vivo appraisal

Attempting to prepare a convenient bioavailable formulation of vitamin B12 (cyanocobalamin), 17 tablet formulations were prepared by direct compression. Different concentrations of hydroxypropyl methyl cellulose (HPMC), carbopol 971p (CP971p), and chitosan (Cs) were used. The tablets were characterized for thickness, weight, drug content, hardness, friability, surface pH, in vitro drug release, and mucoadhesion. Kinetic analysis of the release data was conducted. Vitamin B12 bioavailability from the optimized formulations was studied on rabbits by the aid of enzyme-linked immunosorbent assay. Neurotone® I.M. injection was used for comparison. HPMC (F1-F4), CP971p (F5-F8), and HPMC/CP971p (F12-F15)-based formulations showed acceptable mechanical properties. The formulated tablets showed maximum swelling indices of 232 ± 0.13. The surface pH values ranged from 5.3 ± 0.03 to 6.6 ± 0.02. Bioadhesive force ranged from 66 ± 0.6 to 150 ± 0.5 mN. Results showed that CP971p-based tablets had superior in vitro drug release, mechanical, and mucoadhesive properties. In vitro release date of selected formulations were fitted well to Peppas model. HPMC/CP971p-based formulations showed bioavailability up to 2.7-folds that of Neurotone® I.M. injection.

Methods to assess vitamin B12 bioavailability and technologies to enhance its absorption.

Vitamin B12 (B-12) deficiency is still relatively common in low-, medium-, and high-income countries, mainly because of dietary inadequacy and, to a lesser extent, malabsorption. This narrative review is based on a systematic search of evidence on methods to assess B-12 bioavailability and technologies to enhance its absorption. A total of 2523 scientific articles identified in PubMed and 1572 patents identified in Orbit Intelligence were prescreened. Among the reviewed methods, Schilling's test and/or its food-based version (using cobalamin-labeled egg yolk) were used for decades but have been discontinued, largely because they required radioactive cobalt. The qualitative CobaSorb test, based on changes in circulating holo-transcobalamin before and after B-12 administration, and the 14C-labeled B-12 test for quantitative measurement of absorption of a low-dose radioactive tracer are currently the best available methods. Various forms of B-12 co-formulated with chemical enhancers (ie, salcaprozate sodium, 8-amino caprylate) or supplied via biotechnological methods (ie, microbiological techniques, plant cells expressing cobalamin binding proteins), encapsulation techniques (ie, emulsions, use of chitosan particles), and alternative routes of administration (ie, intranasal, transdermal administration) were identified as potential technologies to enhance B-12 absorption in humans. However, in most cases the evidence of absorption enhancement is limited.

Nitrous oxide induced subacute combined degeneration with longitudinally extensive myelopathy with inverted V-sign on spinal MRI: a case report and literature review

BackgroundNitrous oxide (N2O), a long-standing anesthetic, is also neurotoxic by interfering with the bioavailability of vitamin B12 if abused. A few case studies have reported the neurological and psychiatric complications of N2O.Case presentationHere, we reported a patient of N2O induced subacute combined degeneration (SCD) with longitudinally extensive myelopathy with inverted V-sign exhibiting progressive limb paresthesia and unsteady gait.ConclusionsThis case raises the awareness of an important mechanism of neural toxicity of N2O, and clinical physicians should be well recognized this in the field of substance-related disorders.

Vitamin B12 deficiency and impaired expression of amnionless during aging.

BackgroundPhysical frailty and loss of mobility in elderly individuals lead to reduced independence, quality of life, and increased mortality. Vitamin B12 deficiency has been linked to several age‐related chronic diseases, including in the musculo‐skeletal system, where vitamin B12 deficiency is generally believed to be linked to poor nutritional intake. In the present study, we asked whether aging and frailty associate with altered vitamin B12 homeostasis in humans and investigated the underlying molecular mechanisms using preclinical models.MethodsWe analysed a subset of the Singapore Longitudinal Aging Study and stratified 238 participants based on age and Fried frailty criteria. Levels of methyl‐malonic acid (MMA), a marker for vitamin B12 deficiency, and amnionless, the vitamin B12 co‐receptor that anchors the vitamin B12 transport complex to the membrane of epithelial cells, were measured in plasma. In addition, vitamin B12 levels and the molecular mechanisms of vitamin B12 uptake and excretion were analysed in ileum, kidney, liver, and blood using a rat model of natural aging where nutritional intake is fully controlled.ResultsWe demonstrate that aging and frailty are associated with a higher prevalence of functional vitamin B12 deficiency that can be detected by increased levels of MMA in blood (ρ = 0.25; P = 0.00013). The decline in circulating vitamin B12 levels is recapitulated in a rat model of natural aging where food composition and intake are stable. At the molecular level, these perturbations involve altered expression of amnionless in the ileum and kidney. Interestingly, we demonstrate that amnionless can be detected in serum where its levels increase during aging in both rodents and human (P = 3.3e‐07 and 9.2e‐07, respectively). Blood amnionless levels negatively correlate with vitamin B12 in rats (r2 = 0.305; P = 0.0042) and positively correlate with the vitamin B12 deficiency marker MMA in humans (ρ = 0.22; P = 0.00068).ConclusionsOur results demonstrate that aging and frailty cause intrinsic vitamin B12 deficiencies, which can occur independently of nutritional intake. Mechanistically, vitamin B12 deficiency involves the physio‐pathological decline of both the intestinal uptake and the renal reabsorption system for vitamin B12. Finally, amnionless is a novel biomarker which can detect perturbed vitamin B12 bioavailability during aging and physical frailty.

Vitamin B12–Loaded Buccoadhesive Films as a Noninvasive Supplement in Vitamin B12 Deficiency: In Vitro Evaluation and In Vivo Comparative Study With Intramuscular Injection

This study aimed to formulate and evaluate vitamin B12–loaded buccal mucoadhesive hydrogel films. Various film formulations were prepared using chitosan and polyvinyl alcohol. The prepared films were characterized for thickness, weight variation, drug content, percentage moisture uptake and moisture content, surface pH, mechanical properties, in vitro release, and mucoadhesion. Vitamin B12 bioavailability from the optimized formulation was studied on rabbits by the aid of enzyme-linked immunosorbent assay. Neuroton® I.M. injection was used for comparison. The films had acceptable mechanical and mucoadhesion properties. The percentages of moisture content of the optimized formulation were 3.2 ± 0.95, whereas the percentage drug released was 98.59 ± 1.41% at the end of 40 min. FTIR revealed the incidence of drug/polymer interaction. Differential scanning calorimetry revealed the possibility of the dispersion of cyanocobalamin in a molecular state with complete amorphization in the polymers. The estimated AUC0-8h showed 1.5-fold increases in the bioavailability of cyanocobalamin from the optimized formulation compared with the marketed I.M. injection. These findings warrant that vitamin B12 buccal film formulation can be considered as an effective alternative portal with noninvasive and more convenient characteristics compared with the I.M. injection dosage form.

Short communication: Casein hydrolysate and whey proteins as excipients for cyanocobalamin to increase intestinal absorption in the lactating dairy cow

Bioavailability of vitamin B12 is low in humans and animals. Improving vitamin B12 absorption is important for optimal performance in dairy cows and for increasing vitamin B12 concentrations in milk for human consumption. However, when supplemented in the diet, 80% of synthetic vitamin B12, cyanocobalamin (CN-CBL), is degraded in the rumen of dairy cows and only 25% of the amount escaping destruction in the rumen disappears from the small intestine between the duodenal and ileal cannulas. In pigs, vitamin B12 from milk is more efficiently absorbed than synthetic CN-CBL. The objective of this study was to determine the efficacy of casein hydrolysate and whey proteins as excipients for CN-CBL to increase portal-drained viscera (PDV) flux of the vitamin in lactating dairy cows. Four multiparous lactating Holstein cows (237±17 DIM) equipped with a rumen cannula and catheters in the portal vein and a mesenteric artery were used in a randomized Youden square design. They were fed every 2h to maintain steady digesta flow. On experimental days, they received a postruminal bolus of (1) CN-CBL alone (0.1g), (2) CN-CBL (0.1g) + casein hydrolysate (10g), or (3) CN-CBL (0.1g) + whey proteins (10g). Starting 30 min after the bolus, blood samples were taken simultaneously from the 2 catheters every 15 min during the first 2h and then every 2h until 24h postbolus. Milk yield, DMI, and vitamin B12 portal-arterial difference and PDV flux were analyzed using the MIXED procedure of SAS. Milk yield and DMI were not affected by treatments. The portal-arterial difference of vitamin B12 during the 24-h period following the bolus of vitamin was greater when the vitamin was given in solution with casein hydrolysate (2.9±4.6 pg/mL) than alone (−17.5±5.2 pg/mL) or with whey protein (−13.4±4.2 pg/mL). The treatment effects were similar for the PDV flux. The present results suggest that CN-CBL given with casein hydrolysate increases vitamin B12 absorption as compared with CN-CBL given alone.

Nutritional profile of Indian vegetarian diets--the Indian Migration Study (IMS).

BackgroundThe cardiovascular and other health benefits and potential harms of protein and micronutrient deficiency of vegetarian diets continue to be debated.MethodsStudy participants included urban migrants, their rural siblings and urban residents (n = 6555, mean age - 40.9 yrs) of the Indian Migration Study from Lucknow, Nagpur, Hyderabad and Bangalore. Information on diet (validated interviewer-administered semi-quantitative food frequency questionnaire), tobacco, alcohol, physical activity, medical histories, as well as blood pressure, fasting blood and anthropometric measurements were collected. Nutrient databases were used to calculate nutrient content of regional recipes. Vegetarians ate no eggs, fish, poultry and meat. Using multivariate linear regression with robust standard error model, we compared the macro- and micro-nutrient profile of vegetarian and non-vegetarian diets.ResultsVegetarians, (32.8% of the population), consumed greater amounts of legumes, vegetables, roots and tubers, dairy and sugar, while non-vegetarians had a greater intake of cereals, fruits, spices, salt (p < 0.01), fats and oils. Vegetarians had a higher socioeconomic status, and were less likely to smoke, drink alcohol (p < 0.0001) and engage in less physical activity (p = 0.04). On multivariate analysis, vegetarians consumed more carbohydrates (β = 7.0 g/day (95% CI: 9.9 to 4.0), p < 0.0001), vitamin C (β = 8.7 mg/day (95% CI: 4.3 to13.0), p < 0.0001) and folate (β = 8.0 mcg/day (95% CI: 3.3 to 12.7), p = 0.001) and lower levels of fat (β = −1.6 g/day (95% CI: −0.62 to −2.7), p = 0.002), protein (β = −6.4 g/day (95% CI: −5.8 to −7.0), p < 0.0001), vitamin B12 (β = −1.4 mcg/day (95% CI: −1.2 to −1.5), p < 0.0001) and zinc (β = −0.6 mg/day (95% CI: −0.4 to −0.7), p < 0.0001).ConclusionOverall, Indian vegetarian diets were found to be adequate to sustain nutritional demands according to recommended dietary allowances with less fat. Lower vitamin B12 bio-availability remains a concern and requires exploration of acceptable dietary sources for vegetarians.

Development and in vivo evaluation of an oral vitamin B12 delivery system

Recently, poly(acrylic acid)-cysteine (PAA-cys) based formulations have shown to modulate vitamin B12 absorption across Caco-2 cells monolayers and rat intestinal mucosa. The aim of the present study was to provide a proof-of-principle for a delivery system based on PAA-cys in vivo by administering vitamin B12 to Sprague Dawley rats. In vitro, the permeation enhancing effect of unmodified and thiolated PAA was evaluated using rat intestinal mucosa mounted on Ussing type chambers and was compared to that of verapamil and reduced glutathione (GSH). Vitamin B12 transport in the presence of 0.5% (m/v) PAA-cys was 3.96-fold improved compared to buffer, while 91.5% and 56.5% increased compared to verapamil and GSH, respectively. In vivo, the oral administration of minitablets based on 0.5mg vitamin B12 with 4.5mg PAA or PAA-cys resulted in a significant improvement of vitamin B12 absolute bioavailability. The area under the serum concentration–time curve (AUC0–8) of vitamin B12 after administration of PAA and PAA-cys minitablets was 1.74-fold and 2.92-fold higher in comparison with oral solution, respectively. Thiolated formulations provided an absolute bioavailability of 0.89%. According to the achieved results, PAA-cys can be considered a valuable tool for improving the oral bioavailability of vitamin B12.

Study of chicken egg protein influence on bioavailability of vitamin B12 by SEC-ICP MS and ESI MS

The goal of the presented study was to provide preliminary information on cobalt speciation in chicken eggs. Simulation of a digestive system was set up to acquire information about bioavailability of cobalt. Additionally, it was found that cobalt recovery by means of enzymatic digestion was decreasing with longer boiling time from 100 to 62%. Size exclusion, silica based column was coupled to ICP MS and used for separation of B12 analogues from their degradation products and adducts with proteins extracted from egg tissue. Silica based column offered detection limits down to 0.1 ng mL−1 due to higher recovery of cobalt from stationary phase in comparison to most commonly used Superdex (DL 10 ng mL−1). Phosphitin and ovalbumin showed good affinity to B12 and they were assigned to cobalophilins responsible for protection of cobalamins from enzymatic, acidic or thermal degradation.

In vivo enrichment of chicken eggs with 14C‐B12 for determining vitamin B12 bioavailability in humans

Animal source foods such as eggs are the only natural dietary source of vitamin B12 but there is limited information on its bioavailability from these sources. The objective was to test the feasibility of enriching eggs in vivo with sufficient 14C‐B12 for use in human bioavailability studies. 14C‐B12 was biosynthesized using Salmonella enterica, purified and injected into the thigh muscle of a laying hen. Eggs were collected 21 d, pooled, scrambled and cooked. A serving of egg containing ~0.7 μg 14C‐B12 (~30 nCi) was fed to each of 10 healthy humans after an overnight fast. 14C, detected by accelerator mass spectrometry, first appeared in plasma at 3–4 h after dose and peaked at 7–10 h, with 5–40% appearing in urine in the first 24 h. Fecal 14C analyses in progress will enable calculation of % bioavailability of B12. We conclude that this protocol can be used for human B12 bioavailability studies. Funded by the American Egg Board.