Human Vitamin Research Articles

The validation of an LC-MS/MS method for the quantification of vitamin D metabolites in human milk and their biological variability in Gambian women.

Vitamin D is required for healthy growth and development, but data on human milk vitamin D content is limited. We describe a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the analysis of vitamin D metabolites in human milk, and its application in samples collected on two consecutive days from women in rural Gambia. Vitamin D compounds were extracted from 1mL of milk by liquid-liquid extraction and derivatised with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) prior to analysis by LC-MS/MS. The limit of quantification was 0.05 nmol/L for vitamin D2, 0.025 nmol/L for vitamin D3 and 0.1 nmol/L for 25(OH)D2 and 25(OH)D3. Within- and between-day imprecision was <12% for all analytes except vitamin D2 (14%). From all data combined, geometric mean (-/+ 1SD) vitamin D3 concentration was 0.94 (0.43, 1.80) nmol/L and for 25(OH)D3 0.32 (0.23, 0.42) nmol/L. The intra-individual coefficient of variation (%CV) was 32% and 12% for vitamin D3 and 25(OH)D3, respectively. Inter-individual %CVs were 89% and 34% for vitamin D3 and 25(OH)D3, respectively. There was no significant association between vitamin D metabolite concentrations and milk fat (creamatocrit). Mean vitamin D content of human milk as ARA averaged 42 IU/L with 25(OH)D3 responsible for around two-thirds of the biological activity. In conclusion, this work describes a reliable LC-MS/MS method for quantification of vitamin D and 25(OH)D in low volumes of human milk providing a platform for future work. This study contributes to current understanding of variability of milk vitamin D content.

Kinetics of Riboflavin Production by Hyphopichia wangnamkhiaoensis under Varying Nutritional Conditions.

Riboflavin, an essential vitamin for humans, is extensively used in various industries, with its global demand being met through fermentative processes. Hyphopichia wangnamkhiaoensis is a novel dimorphic yeast species capable of producing riboflavin. However, the nutritional factors affecting riboflavin production in this yeast species remain unknown. Therefore, we conducted a kinetic study on the effects of various nutritional factors-carbon and energy sources, nitrogen sources, vitamins, and amino acids-on batch riboflavin production by H. wangnamkhiaoensis. Batch experiments were performed in a bubble column bioreactor to evaluate cell growth, substrate consumption, and riboflavin production. The highest riboflavin production was obtained when the yeast growth medium was supplemented with glucose, ammonium sulfate, biotin, and glycine. Using these chemical components, along with the mineral salts from Castañeda-Agullo's culture medium, we formulated a novel, low-cost, and effective culture medium (the RGE medium) for riboflavin production by H. wangnamkhiaoensis. This medium resulted in the highest levels of riboflavin production and volumetric productivity, reaching 16.68 mg/L and 0.713 mg/L·h, respectively, within 21 h of incubation. These findings suggest that H. wangnamkhiaoensis, with its shorter incubation time, could improve the efficiency and cost-effectiveness of industrial riboflavin production, paving the way for more sustainable production methods.

Green Innovation and Synthesis of Honeybee Products-Mediated Nanoparticles: Potential Approaches and Wide Applications.

Bee products, abundant in bioactive ingredients, have been utilized in both traditional and contemporary medicine. Their antioxidant, antimicrobial, and anti-inflammatory properties make them valuable for food, preservation, and cosmetics applications. Honeybees are a vast reservoir of potentially beneficial products such as honey, bee pollen, bee bread, beeswax, bee venom, and royal jelly. These products are rich in metabolites vital to human health, including proteins, amino acids, peptides, enzymes, sugars, vitamins, polyphenols, flavonoids, and minerals. The advancement of nanotechnology has led to a continuous search for new natural sources that can facilitate the easy, low-cost, and eco-friendly synthesis of nanomaterials. Nanoparticles (NPs) are actively synthesized using honeybee products, which serve dual purposes in preventive and interceptive treatment strategies due to their richness in essential metabolites. This review aims to highlight the potential role of bee products in this line and their applications as catalysts and food preservatives and to point out their anticancer, antibacterial, antifungal, and antioxidant underlying impacts. The research used several online databases, namely Google Scholar, Science Direct, and Sci Finder. The overall findings suggest that these bee-derived substances exhibit remarkable properties, making them promising candidates for the economical and eco-friendly production of NPs.

Dimeric transport mechanism of human vitamin C transporter SVCT1

Vitamin C plays important roles as a cofactor in many enzymatic reactions and as an antioxidant against oxidative stress. As some mammals including humans cannot synthesize vitamin C de novo from glucose, its uptake from dietary sources is essential, and is mediated by the sodium-dependent vitamin C transporter 1 (SVCT1). Despite its physiological significance in maintaining vitamin C homeostasis, the structural basis of the substrate transport mechanism remained unclear. Here, we report the cryo-EM structures of human SVCT1 in different states at 2.5–3.5 Å resolutions. The binding manner of vitamin C together with two sodium ions reveals the counter ion-dependent substrate recognition mechanism. Furthermore, comparisons of the inward-open and occluded structures support a transport mechanism combining elevator and distinct rotational motions. Our results demonstrate the molecular mechanism of vitamin C transport with its underlying conformational cycle, potentially leading to future industrial and medical applications.

Longitudinal Changes in Human Milk Minerals and Vitamins in the Chinese Population: A Scoping Review.

This scoping review aims to investigate longitudinal changes in minerals and vitamins concentrations in human milk among the Chinese population. Following the PRISMA-ScR guidelines, a comprehensive and systematic literature search was conducted using both English and Chinese databases. Data were extracted and categorized into six defined lactation stages. We found that the concentration of most minerals decreased throughout the lactation period, although calcium (Ca) and magnesium (Mg) fluctuated slightly across lactation periods. Fat-soluble vitamins also showed a decline throughout the lactation period, while water-soluble vitamins exhibited an increasing trend. However, folic acid, biotin, and pantothenic acid demonstrated a downward trend. Overall, this review has identified the longitudinal changes in minerals and vitamins concentrations in human milk among the Chinese population. In order to conduct a more in-depth examination of maternal characteristics and nutritional factors of the composition of human milk, it is recommended to utilize standardized protocols for the collection and analysis of human milk samples.

Vitamin K Epoxide Reductase Complex-Protein Disulphide Isomerase Assemblies in the Thiol-Disulphide Exchange Reactions: Portrayal of Precursor-to-Successor Complexes.

The human Vitamin K Epoxide Reductase Complex (hVKORC1), a key enzyme that converts vitamin K into the form necessary for blood clotting, requires for its activation the reducing equivalents supplied by its redox partner through thiol-disulphide exchange reactions. The functionally related molecular complexes assembled during this process have never been described, except for a proposed de novo model of a 'precursor' complex of hVKORC1 associated with protein disulphide isomerase (PDI). Using numerical approaches (in silico modelling and molecular dynamics simulation), we generated alternative 3D models for each molecular complex bonded either covalently or non-covalently. These models differ in the orientation of the PDI relative to hVKORC1 and in the cysteine residue involved in forming protein-protein disulphide bonds. Based on a comparative analysis of these models' shape, folding, and conformational dynamics, the most probable putative complexes, mimicking the 'precursor', 'intermediate', and 'successor' states, were suggested. In addition, we propose using these complexes to develop the 'allo-network drugs' necessary for treating blood diseases.

Synergy of Mutation-Induced Effects in Human Vitamin K Epoxide Reductase: Perspectives and Challenges for Allo-Network Modulator Design.

The human Vitamin K Epoxide Reductase Complex (hVKORC1), a key enzyme transforming vitamin K into the form necessary for blood clotting, requires for its activation the reducing equivalents delivered by its redox partner through thiol-disulfide exchange reactions. The luminal loop (L-loop) is the principal mediator of hVKORC1 activation, and it is a region frequently harbouring numerous missense mutations. Four L-loop hVKORC1 mutants, suggested in vitro as either resistant (A41S, H68Y) or completely inactive (S52W, W59R), were studied in the oxidised state by numerical approaches (in silico). The DYNASOME and POCKETOME of each mutant were characterised and compared to the native protein, recently described as a modular protein composed of the structurally stable transmembrane domain (TMD) and the intrinsically disordered L-loop, exhibiting quasi-independent dynamics. The DYNASOME of mutants revealed that L-loop missense point mutations impact not only its folding and dynamics, but also those of the TMD, highlighting a strong mutation-specific interdependence between these domains. Another consequence of the mutation-induced effects manifests in the global changes (geometric, topological, and probabilistic) of the newly detected cryptic pockets and the alternation of the recognition properties of the L-loop with its redox protein. Based on our results, we postulate that (i) intra-protein allosteric regulation and (ii) the inherent allosteric regulation and cryptic pockets of each mutant depend on its DYNASOME; and (iii) the recognition of the redox protein by hVKORC1 (INTERACTOME) depend on their DYNASOME. This multifaceted description of proteins produces "omics" data sets, crucial for understanding the physiological processes of proteins and the pathologies caused by alteration of the protein properties at various "omics" levels. Additionally, such characterisation opens novel perspectives for the development of "allo-network drugs" essential for the treatment of blood disorders.

Combining fluorescent quantum dots with transition metal oxide shell as core-shell nanocomposite for turn-on sensing of ascorbic acid

Ascorbic acid (AA) is an essential vitamin in humans, and numerous AA detection studies have been conducted. Most quantum dots (QDs)-based approaches depend on redox reactions involving AA, and they require the introduction of an intermediate (e.g., metal ions, OPD, TMB) or the assembly of fluorescent substances with nanosheets (such as MnO2) that can be degraded by AA. These methods are complex, unstable, and are susceptible to interferences. To address these problems, a core-shell fluorescence probe was developed for turn-on sensing of AA. The transition metal oxide shell FeOOH was generated around the surface of CuInZnS QDs to quench the fluorescence. In the presence of AA, the FeOOH shell was decomposed into Fe2+ and the fluorescence of QDs was recovered. Using a physical shell, the obtained nanocomposite realized direct AA detection, avoiding the effects of interfering substances caused by QDs exposure. Moreover, our probe showed great potential in point-of-care tests and was readily adapted for use as a smartphone-assisted paper sensor.

Relationship between human papillomavirus and serum vitamin D levels: a systematic review

BackgroundHuman papillomavirus (HPV) is one of the most prevalent sexually transmitted diseases worldwide. The present review was conducted to accumulate evidence on the relationship between cervicovaginal human papillomavirus infection and serum vitamin D status.MethodsElectronic databases including Web of Science, Embase, Scopus, and PubMed were searched by different combinations of keywords related to “human papillomavirus” and “vitamin D”, obtained from Mesh and Emtree with AND, and OR operators without any time restriction until December 24, 2022. Selection of articles was based on the inclusion and exclusion criteria. Newcastle-Ottawa Scale was used for quality assessment. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist was applied for reporting.ResultsIn total, 276 citations were retrieved. After removing duplicates, and non-related articles, the full texts of 7 articles were reviewed including 11168 participants. Three studies reported that there was a positive relationship between vitamin D deficiency and cervicovaginal human papillomavirus while three studies did not. One study showed a significant positive association between higher vitamin D stores and short-term high-risk human papillomavirus persistence.ConclusionsThe findings showed no firm evidence for any association between serum vitamin D level and cervicovaginal human papillomavirus infection, although the possible association could not be discarded. Further investigations are needed to reach sound evidence.

Adjustable ultraviolet and white light dual emission phosphor Y2Sr(Ga1-yAly)4SiO12:xPr3+ for health lighting.

Mid-ultraviolet light (290-320 nm) can promote human vitamin D synthesis, which helps in the prevention and treatment of rickets and cartilage disease. For people who lack sufficient ultraviolet radiation all year round, it is significant to supplement the ultraviolet component in daily lighting sources. However, there are few luminous materials showing a combination of mid-ultraviolet light and white light emission on the market. Here, we designed a new material, Y2Sr(Ga1-yAly)4SiO12:xPr3+ (YSGAS:xPr3+), which achieves dual emission of 320 nm ultraviolet and white light from a single substrate with a single doped phosphor. Without Al3+ ions, the emission intensity of the Y2SrGa4SiO12:xPr3+ phosphor shows a contribution-dependent relationship, and concentration quenching due to exchange interaction. The crystal field environment was regulated by partially replacing Ga3+ ions with Al3+ ions. After introducing Al3+, YSGAS:xPr3+ phosphors exhibit dual ultraviolet emission (320 nm) and visible light emission. The emission color of YSGAS:xPr3+ can be adjusted by changing the Al3+ concentration, and Y2Sr(Ga0.6Al0.4)4SiO12:1%Pr3+ emits both ultraviolet light and white light. The LED device prepared by using the YSGAS:Pr3+ phosphor and chips shows a color temperature of 4858 K and appropriate CIE coordinates of (0.3474, 0.3390), indicating wide application prospects in the field of "health lighting" for particular populations.

A Review of Afamin A Metabolic Novel Marker of Many Diseases

Human plasma vitamin E-binding glycoprotein afamin is mostly produced in the liver and released into the circulation. The review in this study related to a glycoprotein afamin marker that is important in many disease(Type 2 diabetes mellitus,cancer,obesity , Gestational diabetes mellitus,oxidative stress,and metabolic syndrome. Although ovarian follicles and human cerebrospinal fluid also contain sizable amounts of AFM, the liver is the main organ that generates it. Though there are minor AFM manifestations have been also reported in the human heart, testis, brain, kidney, and ovary. Afamin is promising metabolic novel marker for gestational diabetes,type 2 diabetes mellitus cancer,metabolic syndrome,and related disease.

Carnauba Wax Applied to the Shell Surface of Chicken Eggs Improved the Shelf Life and Internal Quality of the Eggs

The egg is a nutrient-rich food, essential for human health, containing proteins, vitamins, and minerals. However, it is perishable and begins to lose internal quality shortly after being laid. The quality of eggs deteriorates due to the loss of water and carbon dioxide, which is more pronounced at higher temperatures. Therefore, the aim of this study was to investigate the effect of coating eggs with a semi-solid product formulated with carnauba wax on the preservation and internal quality of eggs during a 28-day storage period at room temperature. 144 white eggs from 50-week-old hens were used, divided into three groups: eggs coated with carnauba wax, eggs coated with mineral oil (positive control), and a control group without coating (negative control). The results were subjected to analysis of variance (ANOVA), followed by the comparison of means through the Tukey test at a significance level of 5% (p&lt;0.05), using the statistical program SISVAR. Eggs coated with carnauba wax showed less weight loss throughout the storage period, lower pH in both the yolk and albumen, higher yolk index and higher Haugh Unit compared to uncoated eggs and eggs coated with mineral oil. This suggests a significant improvement in the quality of coated eggs. Therefore, the use of carnauba wax coating can be an effective solution for extending the shelf life and preserving the quality of eggs, especially in regions where refrigerated storage cannot be guaranteed.

The effects of prenatal and postnatal high-dose vitamin B-12 supplementation on human milk vitamin B-12: a randomized, double-blind, placebo-controlled trial in Tanzania

BackgroundVitamin B-12 status in human milk (HM) has critical implications for infant growth and development. Few studies have separately evaluated the effects of prenatal and postnatal maternal high-dose vitamin B-12 supplementation on HM vitamin B-12 concentration. ObjectivesThis randomized controlled trial aimed to assess the effects of prenatal and postnatal vitamin B-12 supplementation on HM vitamin B-12 at 6 wk and 7 mo postpartum. MethodsPregnant women were enrolled in Dar es Salaam, Tanzania, between 2001 and 2004. From recruitment (12–27 weeks of gestation) through 6 wk postpartum, participants were randomly assigned to daily oral multiple micronutrient supplementation or placebo. From 6 wk to 18 mo postpartum, a subset of participants was randomly assigned to a postnatal supplement or placebo. The supplement included 50 μg/d of vitamin B-12 and various other vitamins. HM vitamin B-12 concentrations were analyzed at 6 wk and 7 mo postpartum for 412 participants. ResultsThe prevalence of HM vitamin B-12 of <310 pmol/L was 73.3% and 68.4% at 6 wk and 7 mo postpartum, respectively. Prenatal supplementation increased HM vitamin B-12 concentration (percent difference: 34.4; 95% CI: 17.0, 54.5; P < 0.001) at 6 wk; this effect was not present at 7 mo. Postnatal supplementation increased HM vitamin B-12 concentration (percent difference: 15.9; 95% CI: 1.91, 31.9; P = 0.025) at 7 mo. Effect modification between prenatal and postnatal supplementation on HM vitamin B-12 status at 7 mo was found, with the effects of prenatal and postnatal supplements more pronounced among those receiving control during the other period; the prenatal supplement had a greater effect with postnatal control, and the postnatal supplement had a greater effect with prenatal control. ConclusionsPrenatal maternal vitamin B-12 supplementation has benefits on short-term HM status, and postnatal maternal vitamin B-12 supplementation has benefits on long-term HM status.This trial was registered at clinicaltrials.gov as NCT00197548. https://clinicaltrials.gov/ct2/show/NCT00197548.

Emerging Trends of Human Consumption of Insects and Their Future Conservation

In recent years, there has been a notable surge in the global interest surrounding the consumption of insects, known as entomophagy. This trend is propelled by its potential to address various pressing challenges. Entomophagy is deeply rooted in many cultures historically and is regarded as a sustainable solution to contemporary problems such as food security, environmental sustainability, and public health. In this context, this paper explores the emerging trends in human insect consumption and underscores conservation's pivotal role in securing the future of edible insects. This study unveils the multifaceted benefits of entomophagy by emphasizing the cultural significance of insects as a food source, their environmental advantages, and their potential to improve nutrition and reduce the ecological footprint of food production. Notably, various insects such as crickets, grasshoppers, termites, mealworms, and silkworm provide the primary sources of the human diet, including proteins, fats, vitamins, and minerals. Simultaneously, this review sheds light on the challenges posed by overexploitation, and habitat destruction, necessitating robust strategies for insect conservation. The paper advocates for sustainable harvesting, habitat restoration, public education and awareness, and innovative market strategies as critical tools for preserving insect biodiversity while promoting responsible insect consumption. Ultimately, entomophagy and insect conservation convergence presents an intriguing paradigm for a more sustainable and resilient global food system.

Per, and -Polyfluoroalkyl Substances (PFAS): Human Vitamin D Deficiency and Blood Plasma Protein Binding

Per, and -Polyfluoroalkyl Substances (PFAS): Human Vitamin D Deficiency and Blood Plasma Protein Binding

A nutritional supplement during preconception and pregnancy increases human milk vitamin D but not B-vitamin concentrations

Optimal maternal vitamin status during pregnancy and lactation is essential to support maternal and infant health. For instance, vitamin D3 is involved in infant bone development, and B-vitamins are involved in various metabolic processes, including energy production. Through a double-blind randomised controlled trial, we investigated the effects of maternal supplementation from preconception throughout pregnancy until birth on human milk (HM) concentrations of vitamin D3 and B-vitamins. In addition, we aimed to characterise longitudinal changes in milk concentrations of these vitamins. Both control and intervention supplements contained calcium, iodine, iron, β-carotene, and folic acid, while the intervention also contained zinc, vitamins B2, B6, B12, and D3, probiotics, and myo-inositol. HM samples were collected across 4 time points from 1 week to 3 months post-delivery from 158 mothers in Singapore, and 7 time points from 1 week to 12 months from 180 mothers in New Zealand. HM vitamin D was quantified using supercritical fluid chromatography and B-vitamins with mass spectrometry. Potential intervention effects on HM vitamins D3, B2, B6, and B9, as well as other B-vitamin (B1 and B3) concentrations were assessed using linear mixed models with a repeated measures design. Over the first 3 months of lactation, HM 25-hydroxyvitamin D3 concentrations were 20% (95% CI 8%, 33%, P=0.001) higher in the intervention group, with more marked effects in New Zealand. There were no observed intervention effects on HM concentrations of vitamins B1, B2, B3, B6, and B9. In New Zealand mothers, longitudinally, vitamin D3 concentrations gradually increased from early lactation up to 12 months, while vitamins B1 and B2 peaked at 6 weeks, B3 at 3 weeks, and B6 and B9 at 3 months. Maternal supplementation during preconception and pregnancy increased HM vitamin D, but not B-vitamin concentrations in lactation. Further studies are required to examine the discrete benefits of vitamin D supplementation starting preconception vs during pregnancy, and to further characterise the effects of supplementation on later offspring health outcomes. Registered at ClinicalTrials.gov on the 16 July 2015 (identifier NCT02509988); Universal Trial Number U1111-1171-8056. This study was academic-led by the EpiGen Global Research Consortium.

Current evidence of the role of vitamin E in prolonging a healthy life

This is a narrative review of the evidence of α-tocopherol importance in human health, especially with regards to its vitamin role. α-Tocopherol is a potent peroxyl radical scavenger, and this role is prominent in its efficacy in maintaining the metabolic health of tissues. Vitamin E deficiency is discussed as a tool to understand the impact of α-tocopherol’s absence promoting increased lipid peroxidation and polyunsaturated fatty acid depletion. Downstream deficiency consequences include impacts on choline and one-carbon metabolism, glucose and energy metabolism, and their interactions with critical thiols, such as glutathione. Importantly, human vitamin E deficiency, caused by genetic defects in the α-tocopherol transfer protein (α-TTP), provides important clues for the necessity of α-tocopherol for the peripheral nervous system. Moreover, α-TTP expression in the liver, brain, eyes, and placenta illustrates that these tissues are especially vulnerable and require this specific α-tocopherol delivery mechanism for their protection. Although clinical trial evidence is limited and equivocal about the health benefits of vitamin E supplements, there is epidemiologic evidence of the long-term benefits of increased α-tocopherol intakes in ’healthy’ diets (high in vegetables and fruits, fish, nuts, and seeds, as well as fiber). Significance statement The elaborate regulation of α-tocopherol concentrations by the human body suggests that the consistent consumption of the recommended amounts of dietary α-tocopherol (15 mg) over a lifetime are protective of the at-risk tissues, as well as providing protection from chronic diseases.

Can vitamin B6 alleviate the adverse reactions of quadruple anti-Helicobacter pylori regimen? : randomized controlled trial

BackgroundVitamin B6 is an essential water-soluble vitamin for humans. It is often used to prevent a variety of neuropathies, relieve vomiting, and relieve symptoms such as hand and foot neuritis.AimTo evaluate whether vitamin B6 can alleviate the adverse reactions caused by the quadruple anti-Helicobacter pylori treatment regimen containing minocycline and metronidazole.MethodsIn this randomized controlled trial, 280 patients with H. pylori infection were randomly placed into one of two treatment groups—the conventional treatment group and the vitamin B6 supplement treatment group—for 2 weeks. The primary endpoint was the total incidence of adverse reactions up to 2 weeks after treatment initiation. The study was designed according to CONSORT Medicinal Interventions. And it was registered with Chinese Clinical Trial Registry under the number ChiCTR2100053833.ResultsIn terms of efficacy, vitamin B6 does not affect the efficacy of conventional regimen. In the vitamin B6 supplement treatment group, the incidence of adverse reactions was 56.92%, which was significantly lower than the 74.62% observed in the conventional treatment group. In addition, the severity of adverse reactions was also significantly reduced. The proportion of moderate to severe central nervous system symptoms decreased from 58.7 to 14.63%. And, the proportion of moderate to severe gastrointestinal reactions decreased from 33.33 to 0%. We speculate that the mechanism of vitamin B6 of reducing adverse reaction may be related to the production of GABA in the brain.ConclusionsVitamin B6 can alleviate adverse reactions of the quadruple anti-H. pylori regimen containing minocycline and metronidazole.

Soil microbiome influences human health in the context of climate change.

Soil microbiomes continue to evolve and shape the human microbiota according to external anthropogenic and climate change effects. Ancient microbes are being exposedas a result of glacier melting, soil erosion and poor agricultural practices. Soil microbes subtly regulate greenhouse gas emissions and undergo profound alterations due to poor soil maintenance. This review highlights how the soil microbiome influences human digestion processes, mineral and vitamin production, mental health and mood stimulation. Although much about microbial functions remains unknown, increasing evidence suggests that beneficial soil microbes are vital for enhancing human tolerance to diseases and pathogens. Further research is essential to delineate the specific role of the soil microbiome in promoting human health, especially in light of the increasing anthropogenic pressures and changing climatic conditions.

Analysis of vitamin D metabolites in biological samples using a nanoluc-based vitamin D receptor ligand sensing system: NLucVDR

Many assays are currently being developed to measure the levels of vitamin D metabolites in various samples (such as blood, urine, and saliva). This study focused on the measurement of vitamin D metabolites in serum and urine using the NLucVDR assay system, which consists of a split-type nanoluciferase and ligand-binding domain (LBD) of the human vitamin D receptor. Blood and urine samples were collected from 23 participants to validate the NLucVDR assay. The 25(OH)D3 levels in the serum and urine determined by the NLucVDR assay showed good correlations with those determined by standard analytical methods (ECLIA for serum and LC-MS/MS for urine), with correlation coefficients of 0.923 and 0.844 for serum and urine samples, respectively. In the case of serum samples, 25(OH)D3 levels determined by the NLucVDR assay were in good agreement with those determined by ECLIA. Therefore, the NLucVDR assay is a useful tool for measuring serum 25(OH)D3 levels. The contribution of each vitamin D metabolite to the luminescence intensity obtained during the NLucVDR assay depends on its concentration and affinity for NLucVDR. Thus, the contribution of 25(OH)D3 in serum appears to be much higher than that of the other metabolites. In contrast, the 25(OH)D3 levels in the urine determined by the NLucVDR assay were more than 20-fold higher than those determined by a standard analytical method (LC-MS/MS), suggesting that some vitamin D metabolite(s) in the urine remarkably increased the luminescence intensity of the NLucVDR assay. Notably, the 25(OH)D3 concentration in the urine determined by the NLucVDR assay and the serum 25(OH)D3 concentration determined by standard analytical methods showed a significant positive correlation (r = 0.568). These results suggest that the analysis of a small amount of urine using the NLucVDR assay may be useful for predicting the serum 25(OH)D3 levels.