Metabolism and pharmacokinetics of vitamin D in patients with cystic fibrosis.

Patients with cystic fibrosis (CF) commonly have lower circulating concentrations of 25-hydroxyvitamin D (25(OH)D) than healthy populations. We comprehensively compared measures of vitamin D metabolism among individuals with CF and healthy control subjects. In a cross-sectional study, serum from participants with CF (N = 83) and frequency-matched healthy control subjects by age and race (N = 82) were analyzed for: 25(OH)D2 and 25(OH)D3, 1α,25-dihydroxyvitamins D2 and D3 (1α,25(OH)2D2 and 1α,25(OH)2D3), 24,25-dihydroxyvitamin D3 (24,25(OH)2D3), 4ß,25-dihydroxyvitamin D3 (4ß,25(OH)2D3), 25-hydroxyvitamin D3-3-sulfate (25(OH)D3-S), and 25-hydroxyvitamin D3-3-glucuronide (25(OH)D3-G). In a 56-day prospective pharmacokinetic study, ∼25 µg deuterium-labeled 25(OH)D3 (d6-25(OH)D3) was administered intravenously to participants (N = 5 with CF, N = 5 control subjects). Serum was analyzed for d6-25(OH)D3 and d6-24,25(OH)2D3, and pharmacokinetic parameters were estimated. In the cross-sectional study, participants with CF had similar mean (SD) total 25(OH)D concentrations as control subjects (26.7 [12.3] vs. 27.7 [9.9] ng/mL) and had higher vitamin D supplement use (53% vs. 22%). However, participants with CF had lower total 1α,25(OH)2D (43.6 [12.7] vs. 50.7 [13.0] pg/mL), 4ß,25(OH)2D3 (52.1 [38.9] vs. 79.9 [60.2] pg/mL), and 25(OH)D3-S (17.7 [11.6] vs. 30.1 [12.3] ng/mL) (p < 0.001 for all). The pharmacokinetics of d6-25(OH)D3 and d6-24,25(OH)D3 did not differ between groups. In summary, although 25(OH)D concentrations were comparable, participants with CF had lower 1α,25(OH)2D, 4ß,25(OH)2D3, and 25(OH)D3-S concentrations than healthy controls. Neither 25(OH)D3 clearance, nor formation of 24,25(OH)2D3, appears to account for these differences and alternative mechanisms for low 25(OH)D in CF (i.e., decreased formation, altered enterohepatic recirculation) should be explored.

In Vitro Non-Genomic Effects of Calcifediol on Human Preosteoblastic Cells.

Several recent studies have demonstrated that the direct precursor of vitamin D3, the calcifediol [25(OH)D3], through the binding to the nuclear vitamin D receptor (VDR), is able to regulate the expression of many genes involved in several cellular processes. Considering that itself may function as a VDR ligand, although with a lower affinity, respect than the active form of vitamin D, we have assumed that 25(OH)D3 by binding the VDR could have a vitamin's D3 activity such as activating non-genomic pathways, and in particular we selected mesenchymal stem cells derived from human adipose tissue (hADMSCs) for the in vitro assessment of the intracellular Ca2+ mobilization in response to 25(OH)D3. Our result reveals the ability of 25(OH)D3 to activate rapid, non-genomic pathways, such as an increase of intracellular Ca2+ levels, similar to what observed with the biologically active form of vitamin D3. hADMSCs loaded with Fluo-4 AM exhibited a rapid and sustained increase in intracellular Ca2+ concentration as a result of exposure to 10-5 M of 25(OH)D3. In this work, we show for the first time the in vitro ability of 25(OH)D3 to induce a rapid increase of intracellular Ca2+ levels in hADMSCs. These findings represent an important step to better understand the non-genomic effects of vitamin D3 and its role in endocrine system.

A pilot-randomized, double-blind crossover trial to evaluate the pharmacokinetics of orally administered 25-hydroxyvitamin D3 and vitamin D3 in healthy adults with differing BMI and in adults with intestinal malabsorption.

BACKGROUND: Obese and malabsorptive patients have difficulty increasing serum 25-hydroxyvitamin D [25(OH)D] after taking vitamin D supplementation. Since 25(OH)D is more hydrophilic than vitamin D, we hypothesized that oral 25(OH)D supplementation is more effective in increasing serum 25(OH)D concentrations in these patients. OBJECTIVES: We aimed to investigate the pharmacokinetics of oral 25-hydroxyvitamin D3 [25(OH)D3] and oral vitamin D3 in healthy participants with differing BMI and malabsorptive patients. METHODS: A randomized, double-blind crossover trial was performed in 6 malabsorptive patients and 10 healthy participants who were given 900 µg of either vitamin D3 or 25(OH)D3 orally followed by a pharmacokinetic study (PKS). After ≥28 d from the first dosing, each participant returned to receive the other form of vitamin D and undergo another PKS. For each PKS, serum vitamin D3 and 25(OH)D3 were measured at baseline and at 2, 4, 6, 8, and 12 h and days 1, 2, 3, 7, and 14. Pharmacokinetic parameters were calculated. RESULTS: Data were expressed as means ± SEMs. The PKS of 900 µg vitamin D3 revealed that malabsorptive patients had 64% lower AUC than healthy participants (1177 ± 425 vs. 3258 ± 496 ng · h/mL; P < 0.05). AUCs of 900 µg 25(OH)D3 were not significantly different between the 2 groups (P = 0.540). The 10 healthy participants were ranked by BMI and categorized into higher/lower BMI groups (5/group). The PKS of 900 µg vitamin D3 showed that the higher BMI group had 53% lower AUC than the lower BMI group (2089 ± 490 vs. 4427 ± 313 ng · h/mL; P < 0.05), whereas AUCs of 900 µg 25(OH)D3 were not significantly different between the 2 groups (P = 0.500). CONCLUSIONS: Oral 25(OH)D3 may be a good choice for managing vitamin D deficiency in malabsorption and obesity. This trial was registered at clinicaltrials.gov as (NCT03401541.

Personalise vitamin D3 using physiologically based pharmacokinetic modelling.

Plasma concentration of vitamin D3 metabolite 25-hydroxyvitamin D3 (25(OH)D3 ) is variable among individuals. The objective of this study is to establish an accurate model for 25(OH)D3 pharmacokinetics (PKs) to support selection of a suitable dose regimen for an individual. We collated vitamin D3 and 25(OH)D3 plasma PK data from reported clinical trials and developed a physiologically-based pharmacokinetic (PBPK) model to appropriately recapitulate training data. Model predictions were then qualified with 25(OH)D3 plasma PKs under vitamin D3 and 25(OH)D3 dose regimens distinct from training data. From data exploration, we observed the increase in plasma 25(OH)D3 after repeated dosing was negatively correlated with 25(OH)D3 baseline levels. Our final model included a first-order vitamin D3 absorption, a first-order vitamin D3 metabolism, and a nonlinear 25(OH)D3 elimination function. This structure explained the apparent paradox. Remarkably, the model accurately predicted plasma 25(OH)D3 following repeated dosing up to 1250 µg/d in the test set. It also made sensible predictions for large single vitamin D3 doses up to 50,000 µg in the test set. Model predicts 10 µg/d regimen may be ineffective for achieving sufficiency (plasma 25(OH)D3 ≥ 75 nmol/L) for a severely deficient individual (baseline 25(OH)D3 = 10 nmol/L), and it might take the same person over 200 days to reach sufficiency at 20 µg/d dose. We propose to personalize vitamin D3 supplementation protocol with this PBPK model. It would require measuring 25(OH)D3 baseline levels, which is not routinely performed under the current UK public health advice. STUDY HIGHLIGHTS: WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC? Vitamin D PK exhibits substantial inter-individual variability. Different officially recommended daily doses are confusing. ​ WHAT QUESTION DID THIS STUDY ADDRESS? Is the UK's recommended 10 µg daily dose sufficient? Should everyone be given same dose? ​ WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE? Our model accurately predicts plasma 25(OH)D under daily oral administration of vitamin D3 . The 10 µg daily vitamin D3 dose is insufficient for prophylaxis (plasma 25(OH)D at 75 nmol/L). ​ HOW MIGHT THIS CHANGE DRUG DISCOVERY, DEVELOPMENT, AND/OR THERAPEUTICS? Combining blood test to measure 25(OH)D baseline with this PBPK model will help inform dosage selection and select follow-up date to improve effectiveness of Hypovitaminosis D treatment.

Effects of Simulated Weightlessness on Metabolizing Enzymes and Pharmacokinetics of Folic Acid in SD Rats.

Folic acid (FA) affect human physiology and drug metabolism. Up to now, the effect of microgravity on the pharmacokinetics of FA remains unclear. The pharmacokinetics of FA in Sprague-Dawley (SD) rats are laying a foundation for safe medicine administration of astronauts. Proteins expression of such FA metabolic enzymes as Methyltetrahydrofolate reductase (MTHFR), Cystathionine beta synthase (CBS) and Methionine synthase (MS) in a variety of organs was analyzed with Western-Blot, and mRNA expression was detected by RT-PCR. The plasma concentration-time profile of FA in normal or tail-suspended SD rats was acquired by liquid chromatography-tandem mass spectrometry (LC-MS/MS) after oral administration of FA. Area under curve (AUC) and Cmax of FA in SD rats decreased significantly with extending period of tail-suspension. In terms of expressed level of metabolic enzymes over four suspension terms, as well as the level of the corresponding mRNAs, the following regularities were found: an obvious sharp decline of MTHFR tissue in kidney, a time-dependent increase of CBS in liver tissue and duodenum tissues, the resemblance of MS fluctuation to that of CBS in tested tissues. A four-week simulated microgravity of SD rats exhibits an unequivocal diminish of bioavailability of FA, and simulated microgravity shows a varying effect on the expression of FA-metabolizing enzyme in a variety of tissues.

Effects of colon-targeted vitamins on the composition and metabolic activity of the human gut microbiome- a pilot study.

An increasing body of evidence has shown that gut microbiota imbalances are linked to diseases. Currently, the possibility of regulating gut microbiota to reverse these perturbations by developing novel therapeutic and preventive strategies is being extensively investigated. The modulatory effect of vitamins on the gut microbiome and related host health benefits remain largely unclear. We investigated the effects of colon-delivered vitamins A, B2, C, D, and E on the gut microbiota using a human clinical study and batch fermentation experiments, in combination with cell models for the assessment of barrier and immune functions. Vitamins C, B2, and D may modulate the human gut microbiome in terms of metabolic activity and bacterial composition. The most distinct effect was that of vitamin C, which significantly increased microbial alpha diversity and fecal short-chain fatty acids compared to the placebo. The remaining vitamins tested showed similar effects on microbial diversity, composition, and/or metabolic activity in vitro, but in varying degrees. Here, we showed that vitamins may modulate the human gut microbiome. Follow-up studies investigating targeted delivery of vitamins to the colon may help clarify the clinical significance of this novel concept for treating and preventing dysbiotic microbiota-related human diseases. Trial registration: ClinicalTrials.gov, NCT03668964. Registered 13 September 2018 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03668964.

Improving the bioavailability of oil-soluble vitamins by optimizing food matrix effects: A review.

The potency of oil-soluble vitamins (vitamins A, D, E and K) in fortified foods can be improved by understanding how food matrices impact their bioavailability. In this review, the major food matrix effects influencing the bioavailability of oil-soluble vitamins are highlighted: oil content, oil composition, particle size, interfacial properties, and food additives. Droplet size and aggregation state in the human gut impact vitamin bioavailability by modulating lipid digestion, vitamin release, and vitamin solubilization. Vitamins in small isolated oil droplets typically have a higher bioavailability than those in large or aggregated ones. Emulsifiers, stabilizers, or texture modifiers can therefore affect bioavailability by influencing droplet size or aggregation. The dimensions of the hydrophobic domains in mixed micelles depends on lipid type: if the domains are too small, vitamin bioavailability is low. Overall, this review highlights the importance of carefully designing food matrices to improve vitamin bioavailability.

Obesity-related asthma in children: A role for vitamin D.

Excess adipose tissue predisposes to an enhanced inflammatory state and can contribute to the pathogenesis and severity of asthma. Vitamin D has anti-inflammatory properties and low-serum levels are seen in children with asthma and in children with obesity. Here we review the intersection of asthma, obesity, and hypovitaminosis D in children. Supplementation with vitamin D has been proposed as a simple, safe, and inexpensive adjunctive therapy in a number of disease states. However, little research has examined the pharmacokinetics of vitamin D and its therapeutic potential in children who suffer from obesity-related asthma.

Microbial Metabolites, Postbiotics, and Intestinal Epithelial Function.

Chronic inflammatory disorders are rising worldwide. The implication of the microbiota in persistent inflammation has been studied for years, but a direct causal relationship has not yet been stablished. Intestinal epithelial cells (IECs) form a protective barrier against detrimental luminal components. Indeed, a decrease in epithelial integrity may trigger a severe inflammatory reaction due to the infiltration of potentially harmful molecules and microorganisms. Bacterial imbalance, more commonly known as dysbiosis, occurs during inflammation and several strategies have been proposed to counteract this condition. Probiotics have been widely used to positively alter the inherited microbial composition and recover a eubiotic status. Nevertheless, probiotics are thought to impair the return of the indigenous microbiome, and to aggravate inflammation in compromised patients. In contrast, postbiotics-bacterial-free metabolites secreted by probiotic strains-have been proposed as a better and safer strategy. Recent scientific studies that have demonstrated the immunomodulatory properties and epithelial protection of postbiotics are summarized in this review, with an emphasis on the available methods that are currently in use to better understand the role of postbiotics in health and nutrition.

Investigation of ex vivo Skin Penetration of Coenzyme Q10 from Microemulsions and Hydrophilic Cream.

INTRODUCTION: Coenzyme Q10 (CoQ10) has been widely used in topical and cosmeceutical products due to its cutaneous antioxidant and energizer effects. CoQ10 is found in a higher concentration in the epidermis compared to dermis. The epidermal level of CoQ10 can be reduced due to several factors such as skin UV irradiation and photoaging. Various dermal nano-formulations have been investigated to overcome the skin barrier and enhance the poor penetration of CoQ10. The nanocarriers are designed to target and concentrate the CoQ10 in the viable epidermis. Most of these studies, however, failed to show the depth and extent of penetration of CoQ10 from the various carrier systems. OBJECTIVE: The distribution of CoQ10 across the various skin layers has to be shown using skin slices representing the different skin layers. METHODS: To realize this objective, a sensitive and selective HPLC method was developed and validated for the quantification of CoQ10 in the different skin slices. The method applicability to skin penetration (using excised human skin) as well as stability studies was investigated using CoQ10-loaded lecithin-based microemulsion (ME) and hydrophilic cream formulations. RESULTS: It could be shown that the highest concentration of CoQ10 in the viable epidermis, the target skin layer for CoQ10, was observed after application of the CoQ10 in the hydrophilic cream. This cream contains 10% of 2-ethylhexyl laurate which works obviously as a penetration enhancer for CoQ10. In contrast, the penetration of CoQ10 was lower from the ME. Just in the deeper dermis, a certain amount of CoQ10 could be detected. CONCLUSIONS: The HPLC method quantified the trace quantities of the CoQ10 distributed across the various skin layers and, hence, can be used to investigate the skin penetration of CoQ10 from various dermal standard and nano-formulations.

Differential effects of vitamin D3 vs vitamin D2 on cellular uptake, tissue distribution and activation of vitamin D in mice and cells.

To combat vitamin D deficiency, vitamin D3 and vitamin D2 are commonly used as a supplement or to fortify food sources. Human data show that the response of 25-hydroxyvitamin D (25(OH)D) to supplementation with vitamin D3 is higher than to vitamin D2. To elucidate the metabolic route of both vitamers, we conducted a study with vitamin D-depleted mice, which were allotted into three groups (n = 12) and received equal doses of either deuterated vitamin D3, deuterated vitamin D2 or both for 4 weeks. To further investigate the hepatic uptake and hydroxylation of both D-vitamers to 25(OH)D, we conducted cell culture experiments with murine and human hepatoma cells (Hepa1-6 and HepG2). The vitamin D metabolite concentrations in serum, tissues and cells were analyzed by LC-MS/MS or ELISA. In mice, vitamin D2 resulted in lower serum and tissue concentrations of vitamin D (P < 0.001) than vitamin D3, while the group which received both D-vitamers showed values in between. Interestingly, vitamin D2 fed mice had 1.9-times and 2.9-times higher serum concentrations of total and free 25(OH)D (P < 0.001) than mice fed vitamin D3, while the concentration of 1,25-dihydroxyvitamin D (1,25(OH)2D) was 1.8-times lower (P < 0.001). The gene and protein expression of enzymes, involved in the hydroxylation and renal uptake of vitamin D remained largely unaffected by the D-vitamer. In contrast to the mice data, hepatoma cells preferred vitamin D3 for 25-hydroxylation over vitamin D2 (P < 0.001). In general, the formation of 25(OH)D was much more pronounced in human than in murine hepatoma cells (P < 0.001). To conclude, in contrast to humans, vitamin D2 was more efficient in increasing 25(OH)D than vitamin D3 in mice, although this difference was not caused by a preferential hydroxylation of vitamin D2 in the liver. The metabolic routes of D3 and D2 in mice differ, showing lower circulating 1,25(OH)2D and tissue vitamin D concentrations in D2- than in D3-fed mice.

Revealing the targets and mechanisms of vitamin A in the treatment of COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), an epidemic disease characterized by rapid infection and a high death toll. The clinical diagnosis of patients with COVID-19 has risen sharply, especially in Western countries. Globally, an effective treatment for COVID-19 is still limited. Vitamin A (VA) exhibits pharmacological activity in the management of pneumonia. Thus, we reason that VA may potentially serve as an anti-SARS-CoV-2 regimen. In this study, bioinformatics analysis and computation assays using a network pharmacology method were conducted to explore and uncover the therapeutic targets and mechanisms of VA for treating COVID-19. We identified candidate targets, pharmacological functions, and therapeutic pathways of VA against SARS-CoV-2. Bioinformatics findings indicate that the mechanisms of action of VA against SARS-CoV-2 include enrichment of immunoreaction, inhibition of inflammatory reaction, and biological processes related to reactive oxygen species. Furthermore, seven core targets of VA against COVID-19, including MAPK1, IL10, EGFR, ICAM1, MAPK14, CAT, and PRKCB were identified. With this bioinformatics-based report, we reveal, for the first time, the anti-SARS-CoV-2 functions and mechanisms of VA and suggest that VA may act as a potent treatment option for COVID-19, a deadly global epidemic.

Enhancement in brain uptake of vitamin D3 nanoemulsion for treatment of cerebral ischemia: formulation, gamma scintigraphy and efficacy study in transient middle cerebral artery occlusion rat models.

AIM: For the treatment of cerebral ischaemia, vitamin-D3 loaded nanoemulsions were developed. METHOD: Tween 20 and polyethylene glycol were chosen as surfactant/co-surfactant, while oleic acid as the oil phase. The formulation was characterised for various in-vitro parameters. Targeting efficiency was investigated through radiometry, gamma scintigraphy and efficacy was studied in transient middle cerebral artery occlusion (MCAo) rat model. RESULT: Vitamin D3-nanoemulsion showed a mean size range of 49.29 ± 10.28 nm with polydispersity index 0.17 ± 0.04 and zeta potential 13.77 mV. The formulation was found stable during thermodynamic stability study and permeated within 180 min through sheep nasal mucosa (permeation coefficient 7.873 ± 0.884 cm/h). Gamma scintigraphy and radiometry assay confirmed better percentage deposition (2.53 ± 0.17%) of 99mTc-vitamin D3-nanoemulsion through nasal route compared to IV administered 99mTc-vitamin D3 solution (0.79 ± 0.03%). Magnetic Resonance Imaging (MRI) of the ischaemic model confirmed better efficacy of vitamin D3-nanoemulsion. CONCLUSION: This work demonstrated better permeation, deposition, and efficacy of vitaminD3-nanoemulsion through the intranasal route.

Micronutrient supplementation of lactating Guatemalan women acutely increases infants' intake of riboflavin, thiamin, pyridoxal, and cobalamin, but not niacin, in a randomized crossover trial.

BACKGROUND: Maternal supplementation during lactation could increase milk B-vitamin concentrations, but little is known about the kinetics of milk vitamin responses. OBJECTIVES: We compared acute effects of maternal lipid-based nutrient supplement (LNS) consumption (n = 22 nutrients, 175%-212% of the RDA intake for the nutrients examined), as a single dose or at spaced intervals during 8 h, on milk concentrations and infant intake from milk of B-vitamins. METHODS: This randomized crossover trial in Quetzaltenango, Guatemala included 26 mother-infant dyads 4-6 mo postpartum who were randomly assigned to receive 3 treatments in a random order: bolus 30-g dose of LNS (Bolus); 3 × 10-g doses of LNS (Divided); and no LNS (Control), with control meals. Mothers attended three 8-h visits during which infant milk consumption was measured and milk samples were collected at every feed. Infant intake was assessed as $\mathop \sum \nolimits_{i\ = \ 1}^n ( {{\rm{milk\ volum}}{{\rm{e}}_{{\rm{feed\ }}n}} \times \ {\rm{nutrient\ concentratio}}{{\rm{n}}_{{\rm{feed}}\ n}}} )$ over 8 h. RESULTS: Maternal supplementation with the Bolus or Divided dose increased least-squares mean (95% CI) milk and infant intakes of riboflavin [milk: Bolus: 154.4 (138.2, 172.5) µg · min-1 · mL-1; Control: 84.5 (75.8, 94.3) µg · min-1 · mL-1; infant: Bolus: 64.5 (56.1, 74.3) µg; Control: 34.5 (30.0, 39.6) µg], thiamin [milk: Bolus: 10.9 (10.1, 11.7) µg · min-1 · mL-1; Control: 7.7 (7.2, 8.3) µg · min-1 · mL-1; infant: Bolus: 5.1 (4.4, 6.0) µg; Control: 3.4 (2.9, 4.0) µg], and pyridoxal [milk: Bolus: 90.5 (82.8, 98.9) µg · min-1 · mL-1; Control: 60.8 (55.8, 66.3) µg · min-1 · mL-1; infant: Bolus: 39.4 (33.5, 46.4) µg; Control: 25.0 (21.4, 29.2) µg] (all P < 0.001). Only the Bolus dose increased cobalamin in milk [Bolus: 0.054 (0.047, 0.061) µg · min-1 · mL-1; Control: 0.041 (0.035, 0.048) µg · min-1 · mL-1, P = 0.039] and infant cobalamin intake [Bolus: 0.023 (0.020, 0.027) µg; Control: 0.015 (0.013, 0.018) µg, P = 0.001] compared with Control. Niacin was unaffected. CONCLUSIONS: Maternal supplementation with LNS as a Bolus or Divided dose was similarly effective at increasing milk riboflavin, thiamin, and pyridoxal and infant intakes, whereas only the Bolus dose increased cobalamin. Niacin was unaffected in 8 h. This trial was registered at clinicaltrials.gov as NCT02464111.

[Bioavailability of natural versus synthetic B vitamins and their effects on metabolic processes]. / Bioverfügbarkeit eines natürlichen versus eines synthetischen Vitamin-B- Komplexes und deren Auswirkungen auf metabolische Prozesse.

BACKGROUND: Owing to the widespread use of vitamin supplements to prevent and compensate for deficiencies, the equivalence of natural versus synthetic vitamins with respect to their bioavailability and metabolic influence is discussed controversially. METHOD: Thirty healthy female (n=22) and male participants (n=8) were investigated in a randomized, double-blind, cross-over study over a supplementation period of 6 weeks for each condition. The participants received a daily dose of a complex of the 8 natural B vitamins (group N), determined by the natural composition of quinoa seedlings, resp. synthetic B vitamins (group S), both corresponding to about 2.5 times the Recommended Dietary Allowance (RDA) of the national nutrition board. The primary criterion under investigation was changes in the blood levels of the individual B vitamins. Secondary criteria were the influence of both B complexes on homocysteine, antioxidant status, polyphenols, peroxide loading and peroxidase activity. RESULTS: Compared to baseline values, serum levels of all B vitamins measured increased: Vitamins B1 (N +23%; S +27%), B2 (N +14%; S +13%), B6 (N +101%; S +101%), B9 (N +86%; S +153%) and B12 (N +16%) were elevated at the end of the first supplementation period (p < 0.05), while serum levels of vitamins B1, B9 and B12 remained elevated compared to baseline even after the 2-week washout phase. During the second supplementation period, the vitamin concentrations in group N, with the exception of vitamin B1, could be increased once again (p < 0.05). In contrast, in group S only for vitamins B2 and B12 substantial increases (p < 0.05) were found. The influence of B vitamins on metabolic parameters such as homocysteine and polyphenols, which were markedly reduced, was also clearly measurable; however, total antioxidant capacity and peroxidase activity increased. The peroxide concentration remained almost unchanged in both groups. CONCLUSION: This clinical pilot study showed comparable bioavailability for both natural and synthetic B vitamins, with a 2.5-fold concentration of the RDA. Both vitamin B preparations showed a clear influence on metabolic parameters, whereas that of the natural B vitamins tended to have a slightly stronger effect than the synthetic analogues.

Vitamin D Metabolism Is Dysregulated in Asthma and Chronic Obstructive Pulmonary Disease.

Rationale: Vitamin D deficiency is common in patients with asthma and chronic obstructive pulmonary disease (COPD). Low 25-hydroxyvitamin D (25[OH]D) levels may represent a cause or a consequence of these conditions.Objectives: To determine whether vitamin D metabolism is altered in asthma or COPD.Methods: We conducted a longitudinal study in 186 adults to determine whether the 25(OH)D response to six oral doses of 3 mg vitamin D3, administered over 1 year, differed between those with asthma or COPD versus control subjects. Serum concentrations of vitamin D3, 25(OH)D3, and 1α,25-dihydroxyvitamin D3 (1α,25[OH]2D3) were determined presupplementation and postsupplementation in 93 adults with asthma, COPD, or neither condition, and metabolite-to-parent compound molar ratios were compared between groups to estimate hydroxylase activity. Additionally, we analyzed 14 datasets to compare expression of 1α,25(OH)2D3-inducible gene expression signatures in clinical samples taken from adults with asthma or COPD versus control subjects.Measurements and Main Results: The mean postsupplementation 25(OH)D increase in participants with asthma (20.9 nmol/L) and COPD (21.5 nmol/L) was lower than in control subjects (39.8 nmol/L; P = 0.001). Compared with control subjects, patients with asthma and COPD had lower molar ratios of 25(OH)D3-to-vitamin D3 and higher molar ratios of 1α,25(OH)2D3-to-25(OH)D3 both presupplementation and postsupplementation (P ≤ 0.005). Intergroup differences in 1α,25(OH)2D3-inducible gene expression signatures were modest and variable if statistically significant.Conclusions: Attenuation of the 25(OH)D response to vitamin D supplementation in asthma and COPD associated with reduced molar ratios of 25(OH)D3-to-vitamin D3 and increased molar ratios of 1α,25(OH)2D3-to-25(OH)D3 in serum, suggesting that vitamin D metabolism is dysregulated in these conditions.

Transdermal vitamin D supplementation-A potential vitamin D deficiency treatment.

Vitamin D deficiency has high prevalence worldwide. Vitamin D3, the active form of vitamin D, exhibits array of roles in body, from calcium homeostasis and bone mineralization to cancer, neurological disorders, immunomodulatory action, and cardiac health. Current approaches for supplementing vitamin D3 are restricted to oral and parenteral routes. This review highlights recent research in the field of transdermal delivery of vitamin D, its active form and analogues with the aid of penetration enhancers and novel carrier system as nutritional supplement in case of vitamin D deficiency. The penetration of vitamin D3 is challenging; however, by means of reducing hydrophobicity of the active and encapsulating vitamin D3 in a suitable carrier system, penetration is achieved. The results show that penetration of vitamin D3 through skin is feasible. Further clinical trials could strengthen these results. However, the present research till date shows transdermal vitamin D3 a promising way of supplementation.

Stability and bioavailability of vitamin D3 encapsulated in composite gels of whey protein isolate and lotus root amylopectin.

A gel delivery system was developed in the present work using whey protein isolate and lotus root amylopectin via regulating pH. The texture, thermodynamics, rheology and microstructure of gels were evaluated. Results showed that pH at 7.0 induced a more compact and stable gel structure than other pH. The composite gel formed at pH 7.0 was accordingly employed to encapsulate vitamin D3. Results exhibited that the encapsulation of composite gel of whey protein isolate and lotus root amylopectin could enhance the storage stability of vitamin D3 and protect vitamin D3 from photochemical degradation. Moreover, this encapsulation could control the release of vitamin D3 in simulated intestinal fluid. Animal experiments exhibited that the bioavailability was significantly increased after vitamin D3 was encapsulated by the composite gel. This work indicated that the whey protein isolate-lotus root amylopectin gel is a good delivery system to improve the stability and bioavailability of vitamin D3.

Vitamin C Bioequivalence from Gummy and Caplet Sources in Healthy Adults: A Randomized-Controlled Trial.

Background: The efficacy of Vitamin C (L-ascorbic acid) supplementation can be assessed by uptake into the blood and retention in leukocytes. Vitafusion® Power C gummy is an alternative vitamin C source which may exhibit similar bioavailability to comparator caplets.Objective: The objective of this study was to evaluate the bioequivalence of vitamin C from a vitafusion® Power C gummy formulation and a comparator caplet in healthy adults.Methods: Thirty healthy men and women, 34.0 ± 11.4 years of age and Body Mass Index (BMI) 24.5 ± 3.6 kg/m2 completed the randomized examiner-blind, comparator controlled, cross-over trial with two sequences: gummy (1000 mg) to caplet (1000 mg) or caplet to gummy. Intake of foods fortified with Vitamin C was restricted 7 days prior to each dosing. Blood samples were collected pre-dose and at 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 h post-dose for plasma and leukocytes; and urine was collected pre-dose and between 0-2, 2-4, 4-8, 8-12 and 12-24 h post-dose for L-ascorbic acid analysis.Results: Vitafusion® Power C gummy and comparator caplet demonstrated similar plasma absorption profiles as there were no significant differences in plasma L-ascorbic acid total Area Under the Curve (AUC)0-24h, and Tmax between gummy and caplet. The caplet did elicit a significantly higher Cmax than the gummy (p < 0.05), however, the difference was numerically small. Leukocyte L-ascorbic acid total AUC0-24h and Cmax were not significantly different between gummy and caplet, however Tmax of the gummy group was significantly longer (p = 0.012). Urinary L-ascorbic acid levels were also not significantly different between gummy and caplet. There were no serious adverse events and safety parameters remained within normal clinical range for both products.Conclusion: Vitafusion® Power C gummy exhibited similar Vitamin C absorption and bioavailability to a comparator caplet in healthy adults and were considered bioequivalent.

Pharmacokinetic data support 6-hourly dosing of intravenous vitamin C to critically ill patients with septic shock.

OBJECTIVES: To study vitamin C pharmacokinetics in septic shock. DESIGN: Prospective pharmacokinetic study. SETTING: Two intensive care units. PARTICIPANTS: Twenty-one patients with septic shock enrolled in a randomised trial of high dose vitamin C therapy in septic shock. INTERVENTION: Patients received 1.5 g intravenous vitamin C every 6 hours. Plasma samples were obtained before and at 1, 4 and 6 hours after drug administration, and vitamin C concentrations were measured by high performance liquid chromatography. MAIN OUTCOME MEASURES: Clearance, volume of distribution, and half-life were calculated using noncompartmental analysis. Data are presented as median (interquartile range [IQR]). RESULTS: Of the 11 participants who had plasma collected before any intravenous vitamin C administration, two (18%) were deficient (concentrations < 11 µmol/L) and three (27%) had hypovitaminosis C (concentrations between 11 and 23 µmol/L), with a median concentration 28 µmol/L (IQR, 11-44 µmol/L). Volume of distribution was 23.3 L (IQR, 21.9-27.8 L), clearance 5.2 L/h (IQR, 3.3-5.4 L/h), and half-life 4.3 h (IQR, 2.6-7.5 h). For the participants who had received at least one dose of intravenous vitamin C before sampling, T0 concentration was 258 µmol/L (IQR, 162- 301 µmol/L). Pharmacokinetic parameters for subsequent doses were a median volume of distribution 39.9 L (IQR, 31.4-44.4 L), clearance 3.6 L/h (IQR, 2.6-6.5 L/h), and half-life 6.9 h (IQR, 5.7-8.5 h). CONCLUSION: Intravenous vitamin C (1.5 g every 6 hours) corrects vitamin C deficiency and hypovitaminosis C and provides an appropriate dosing schedule to achieve and maintain normal or elevated vitamin C levels in septic shock.