Quantitation of total vitamin D2 and D4 in UV-exposed mushrooms using HPLC with UV detection after novel two-step solid phase extraction.

A robust method for quantitation of total vitamin D2 and D4 in mushrooms by high performance liquid chromatography with UV detection (HPLC-UV) was developed to analyze mushrooms exposed to UV light. A two-step solid phase extraction (SPE) (silica, carbon black) removed chromatographic interferences typically resolved only with mass spectrometric detection (LC-MS) and allowed quantitation of all vitamin D and pre-D analytes. The vitamin and pre-vitamin forms of D2, D4 and D3 (internal standard), as well as other photoisomers and sterols were resolved. Results for six types of UV-exposed mushrooms were comparable to LC-MS. Screening of ten additional types of UV-exposed mushrooms without the IS confirmed lack of interference with the IS. The limit of quantification (µg/100 g fresh weight) was 0.4 for vitamin D and 0.9 for pre-vitamin D. Mushrooms do not have to be dried, and separatory funnels and large solvent volumes were also eliminated from sample preparation.

Mixture of air pollution, brominated flame retardants, polychlorinated biphenyls, per- and polyfluoroalkyl substances, and organochlorine pesticides in relation to vitamin D concentrations in pregnancy.

Over two-thirds of pregnant women in the U.S. have insufficient 25(OH)D (Vitamin D) concentrations, which can adversely impact fetal health. Several pollutants have been associated with 25(OH)D, but have not been considered in the context of chemical co-exposures. We aimed to determine associations between a broad mixture of prenatal environmental chemical exposures and 25(OH)D concentrations in mid-pregnancy. Stored mid-pregnancy serum samples were assayed from 421 women delivering live births in Southern California in 2000-2003. 25(OH)D, six BFRs, eleven polychlorinated biphenyls (PCBs), six per- and polyfluoroalkyl substances, and two organochlorine pesticides were detected in ≥60% of specimens. Gestational exposures to airborne particulate matter ≤ 10 µm (PM10) and ≤ 2.5 µm (PM2.5), nitrogen monoxide (NO), nitrogen dioxide (NO2), and ozone concentrations were derived from monitoring station data. Bayesian Hierarchical Modeling (BHM) and Bayesian Kernel Machine Regression (BKMR) analyses estimated overall mixture and individual chemical associations accounting for co-exposures and covariates with mean 25(OH)D levels, and BHM was used to estimate associations with insufficient (<75 nMol/L) 25(OH)D levels. Non-mixture associations for each chemical were estimated with linear and logistic models. PM10 [BHM estimate: -0.133 nmol/l 95% Credible Interval (-0.240, -0.026)] was associated with lower 25(OH)D in BHM and BKMR. Higher quantiles of combined exposures were associated with lower 25(OH)D, though with wide credible intervals. In non-mixture models, PM10, PM2.5, NO, and NO2 were associated with lower concentrations, while O3 and PBDE153 were associated with higher 25(OH)D and/or lower insufficiency. While some chemicals were associated with increased and others with decreased 25(OH)D concentrations, the overall mixture was associated with lower concentrations. Mixture analyses differed from non-mixture regressions, highlighting the importance of mixtures approaches for estimating real-world associations.

Determination of vitamin D metabolites in various biological samples through an improved chemical derivatization assisted liquid chromatography-tandem mass spectrometry approach.

Vitamin D (VD) metabolites are involved in a variety of important metabolic processes and physiological effects in organisms. Profiling of VD metabolites favors a deep understanding of the physiological role of VD. However, VD metabolites are difficult to detect due to their high chemical structural rigidity, structural similarity, and low sensitivities under liquid chromatography-tandem mass spectrometry (LC-MS). Herein, we present a chemical derivatization assisted LC-MS/MS strategy for the detection of VDs, in which 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) is employed to derivatize the conjugated diene of VD metabolites and provides sensitizing reporters for MS detection. After PTAD derivatization, the sensitivities of seven VD metabolites increased by 24-276 folds, with the limits of detection ranging from 3 to 20 pg mL-1. Using this method, we achieved a sensitive and accurate quantification of 7 VD metabolites (vitamin D2, vitamin D3, 25-hydroxyvitamin D2, 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D2, 1,25-dihydroxyvitamin D3, and 1,24,25-trihydroxyvitamin D3) of the VD metabolic pathway in different trace biological samples, including human serum, mouse tissues (namely liver, kidney, lung, and spleen), and cells. We believe that the present method can provide a promising tool for an in-depth analysis of VD metabolism.

Association of bisphenol A with 25(OH)D, 1,25(OH)2D levels and 1,25(OH)2D/25(OH)D ratio in cord blood.

The aim was to investigate the association between bisphenol A (BPA), 25-hydroxy vitamin D [25(OH)D], and 1α,25 dihydroxy vitamin D [1,25(OH)2D] levels in the cord blood of newborn babies. BPA was measured by high pressure liquid chromatography (HPLC) and vitamin D levels by commercial ELISA or ECLIA kits. BPA and Vitamin D levels were grouped according to tertile values. In the cord blood, the median 25(OH)D level was 14.9 ng/mL (IQR: 8.5-20.8) and median 1,25(OH)2D level was 53.3 pg/dL (IQR: 42.3-98.4). 25(OH)D levels were < 20 ng/mL in 76.5% of the babies. BPA was detectable in 72.4% of the cord blood samples; median BPA level was 1.57 ng/mL (IQR: < DL-4.05 ng/mL). Frequencies of vitamin D deficiency and frequencies of cases having the highest tertile active vitamin D levels were similar in groups of BPA tertiles in both univariate and multivariate analysis. In conclusion, both BPA exposure and insufficient vitamin D transfer via cord blood are common in newborns. Bisphenol A levels were not correlated with vitamin D levels in cord blood of healthy mother-fetus pairs.

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.

Comparing derivatization reagents for quantitative LC-MS/MS analysis of a variety of vitamin D metabolites.

The present study systematically compares the sensitivity and selectivity of the analysis of multiple vitamin D metabolites after chemical derivatization using different reagents for liquid chromatography-tandem mass spectrometry (LC-MS/MS). Generally, chemical derivatization is applied to vitamin D metabolites to increase the ionization efficiency, which is particularly important for very low abundant metabolites. Derivatization can also improve the selectivity of the LC separation. A wide variety of derivatization reagents has been reported in recent years, but information on their relative performance and applicability to different vitamin D metabolites is, unfortunately, not available in the literature. To fill this gap, we investigated vitamin D3, 3ß-25-hydroxyvitamin D3 (3ß-25(OH)D3), 3α-25-hydroxyvitamin D3 (3α-25(OH)D3), 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) and compared response factors and selectivity after derivatizing with several important reagents, including four dienophile reagents (4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), 4-[2-(6,7-dimethoxy-4-methyl-3-oxo-3,4-dihydroquinoxalinyl)ethyl]-1,2,4-triazoline-3,5-dione (DMEQ-TAD), Amplifex, 2-nitrosopyridine (PyrNO)) as well as two reagents targeting hydroxyl groups: isonicotinoyl chloride (INC) and 2-fluoro-1-methylpyridinium-p-toluenesulfonate (FMP-TS). In addition, a combination of dienophiles and hydroxyl group reagents was examined. For LC separations, reversed-phase C-18 and mixed-mode pentafluorophenyl HPLC columns using different compositions of the mobile phase were compared. With respect to detection sensitivity, the optimum derivatization reagent for the profiling of multiple metabolites was Amplifex. Nevertheless, FMP-TS, INC, PTAD, or PTAD combined with an acetylation reaction showed very good performance for selected metabolites. These reagent combinations provided signal enhancements on the order of 3- to 295-fold depending on the compound. Chromatographic separation of the dihydroxylated vitamin D3 species was readily achieved using any of the derivatization reactions, while for 25(OH)D3 epimers, only PyrNO, FMP, INC, and PTAD combined with acetylation enabled complete separation. In conclusion, we believe this study can serve as a useful reference for vitamin D laboratories, to help analytical and clinical scientists decide which derivatization reagent to choose for their application.

Measuring 25-hydroxyvitamin D in cats: comparison of a whole-blood lateral flow assay, 2 dried-blood-spot tests, and serum LC-MS/MS.

Measuring 25-hydroxyvitamin D (25D) can be a challenge in veterinary medicine because of laboratory accessibility and required sample volume. We compared 2 dried-blood-spot (DBS) tests and a lateral flow assay (LFA) to the gold standard, liquid chromatography-tandem mass spectrometry (LC-MS/MS). We hypothesized that there would be good agreement among the tests, within a clinically significant limit of agreement of ± 25 nmol/L. We collected blood from 6 healthy purpose-bred 2-y-old cats at 6 times over 6 wk, and measured 25D concentrations with all 4 tests. Agreement of the 3 candidate tests and LC-MS/MS was evaluated via Bland-Altman analysis, Passing-Bablok regression, and Lin correlation coefficients. Bland-Altman analysis demonstrated that the mean bias was >± 25 nmol/L for all 3 candidate tests in comparison to serum LC-MS/MS concentrations. The 95% CIs for the mean bias did not include zero, further supporting the presence of significant bias among methods. Additionally, all 3 tests had poor agreement with serum LC-MS/MS concentrations when analyzed by Lin correlation coefficient analysis, and bias between methods was further characterized by Passing-Bablok analysis. Based on these results, none of these 3 tests is recommended as an alternative to LC-MS/MS testing for 25D measurement in cats.

Improving vitamin D content in pork meat by UVB biofortification.

Vitamin D deficiency is prevalent worldwide and identification of alternative food-based strategies are urgently warranted. In two studies, 12-week old crossbred pigs (Duroc x (Large White x Landrace)) were exposed daily to narrowband UVB radiation for ∼10 weeks or control (no UVB exposure) until slaughter. In Study 1 (n = 48), pigs were exposed to UVB for 2 min and in Study 2 (n = 20), this duration was tripled to 6 min. All pigs were fed the maximum permitted 2000 IU vitamin D3/kg feed. Loin meat was cooked prior to vitamin D LC-MS/MS analysis. In Study 1, pork loin vitamin D3 did not differ between groups. Study 2 provided longer UVB exposure time and resulted in significantly higher loin vitamin D3 (11.97 vs. 6.03 µg/kg), 25(OH)D3 (2.09 vs. 1.65 µg/kg) and total vitamin D activity (22.88 vs. 14.50 µg/kg) concentrations, compared to control (P < 0.05). Pigs remained healthy during both studies and developed no signs of erythema. Biofortification by UVB radiation provides an effective strategy to further safely increase the naturally occurring vitamin D content of pork loin, alongside feed supplementation.

Development of Innovative Vitamin D Enrichment Designs for Two Typical Italian Fresh Cheeses: Burrata and Giuncata.

The aim of this research was to develop innovative cheeses fortified with vitamin D3 (VD3). Formulation studies and analyses of textural properties and chemicals were carried out for these developments. Two traditional Italian varieties of cheese (giuncata and burrata) were studied. For giuncata, the fortification of milk for cheese production provided a VD3 retention level of 43.9 ± 0.6% in the food matrix. For burrata, the VD3 ingredient was incorporated into the creamy inner part after mixing, maintaining the textural quality of the product (adhesiveness 4.3 ± 0.4 J × 10-3; firmness 0.7 ± 0.0 N; and cohesiveness 0.8 ± 0.2). The optimized enrichment designs allowed to obtain homogenous contents of VD3 during the production of giuncata (0.48 ± 0.01 µg/g) and burrata cheeses (0.32 ± 0.02 µg/g). Moreover, analyses revealed the high stability of VD3 during the storage of the two fortified cheese types (2 weeks, 4 °C). These fortification designs could be implemented at an industrial scale to obtain new cheese types enriched in VD3 and thus contribute to the reduction in VD deficiency prevalence.

Vitamin D metabolites and analytical challenges.

Vitamin D is an essential micronutrient for bone health and the general cellular functions of the body. Its insufficiency/deficiency leads to the pathophysiology of disorders like diabetes, cancer, autoimmune, neurodegenerative, and cardiovascular diseases. Clinical interest in Vitamin D metabolites and their role in various medical disorders have contributed to an increase in laboratory demands for vitamin D measurements. For clinical and research laboratories worldwide, analysis of vitamin D and associated metabolites is a significant problem. The best way for determining vitamin D levels is constantly being debated. Various methods such as immunoassays and chromatographic techniques are available for determining vitamin D levels. Additionally, biosensors have recently been considered promising options for routine vitamin D analysis. The existing methods and other developments in the measurement of vitamin D metabolites and associated analytical challenges are discussed in this review.

The modifiable effect of vitamin D in the association between long-term exposure to ambient air pollution and glycosylated hemoglobin in patients with hypertension.

OBJECTIVES: Evidence on the association between long-term exposure to ambient air pollution and serum glycosylated hemoglobin A1c (HbA1c) is limited and inconclusive. In addition, whether vitamin D can modify the association between air pollution exposure and glucose metabolism has not been previously investigated. We aimed to evaluate the effects of various air pollutants on serum HbA1c levels in patients with hypertension and, further, to explore the modification effect of individual serum vitamin D levels. METHODS: This study was derived from UK Biobank study, and 246 027 participants with hypertension were included in our analysis. Individual exposures to particulate matters (PMs) and nitrogen oxides were estimated using the land use regression model. The associations between air pollutants and HbA1c were assessed using the multivariable linear regression model. Among the 222 845 participants with a measurement of serum vitamin D, we explored the associations in subgroups stratified by vitamin D levels. RESULTS: Long-term air pollutant exposures were significantly associated with higher HbA1c levels. After adjusting for potential confounders, 10-µg/m3 (or 1-m-1) increases in concentrations of PM with diameters ≤2.5 µm (PM2.5), PM with diameters ≤10 µm, PM with diameters from 2.5 µm to 10 µm, PM2.5 absorbance, nitrogen oxides, and nitrogen dioxide were significantly associated with 0.59 (95% confidence interval, 0.28-0.89), 0.49 (0.33-0.65), 0.81 (0.48-1.14), 0.56 (0.44-0.69), 0.06 (0.04-0.09), and 0.16 (0.12-0.21) mmol/mol increase in serum HbA1c levels, respectively. The associations were weakened but remained significant after additional adjustment of vitamin D. In addition, the associations of air pollutants with HbA1c were more evident in participants with low serum vitamin D levels (all P values for interaction <0.001). CONCLUSIONS: Long-term exposures to ambient air pollutants were associated with higher levels of HbA1c in a dose-response fashion in a large UK cohort. Serum vitamin D status significantly modified these associations, and high serum vitamin D levels may attenuate the relationships between air pollution exposures and HbA1c levels.

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

BACKGROUND & AIMS: 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. METHODS: Both control and intervention supplements contained calcium, iodine, iron, ß-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. RESULTS: 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. CONCLUSIONS: 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. CLINICAL TRIAL REGISTRATION: 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.

Association of blood heavy metal levels with osteocalcin abnormality and incidence of osteoporosis in Saudi subjects / Associação de anormalidades de osteocalcina nos níveis de metais pesados no sangue e incidência de osteoporose em indivíduos sauditas

Serum toxic metals have been implicated in development of many diseases. This study investigated the association between blood levels of lead and cadmium with abnormal bone mineral density (BMD) and incidence of osteoporosis. Sixty Saudi male adults age matching were assigned into two groups: A healthy control group (n = 30) and osteoporosis patients diagnosed according to T-score (n = 30). Serum calcium, vitamin D, osteocalcin, lead, cadmium were measured. Osteoporotic group showed a highly significant elevation of blood lead and cadmium levels compared to the control group (p <0.001). BMD was negatively correlated with serum osteocalcin level compared with control. There was a significant negative correlation between the cadmium and lead levels (r=-0.465 and p-value = 0.01) and calcium (p < 0.004). Our findings suggested that high cadmium and lead were negative correlated to BMD and increased the risk factor for osteoporosis.

Os metais tóxicos do soro têm sido implicados no desenvolvimento de muitas doenças. Este estudo investigou a associação entre os níveis sanguíneos de chumbo e cádmio com densidade mineral óssea anormal (DMO) e incidência de osteoporose. Sessenta adultos sauditas do sexo masculino com idades iguais foram divididos em dois grupos: um grupo de controle saudável (n = 30) e pacientes com osteoporose diagnosticados de acordo com o T-score (n = 30). Cálcio sérico, vitamina D, osteocalcina, chumbo, cádmio foram medidos. O grupo osteoporótico apresentou elevação altamente significativa dos níveis de chumbo e cádmio no sangue em comparação ao grupo controle (p < 0,001). A DMO foi negativamente correlacionada com o nível de osteocalcina sérica em comparação com o controle. Houve correlação negativa significativa entre os níveis de cádmio e chumbo (r = -0,465 ep = 0,01) e cálcio (p < 0,004). Nossos achados sugeriram que cádmio e chumbo elevados foram correlacionados negativamente à DMO e aumentaram o fator de risco para osteoporose.

Particulate matter may have a limited influence on maternal vitamin D levels.

Evidence for an association between the amount of particulate matter (PM) in the atmosphere and vitamin D status of pregnant women is limited. We aimed to examine the independent association between PM and maternal levels of serum 25-hydroxyvitamin D (25OHD) during the second trimester and to explore possible modifications to the association by meteorological factors. 27,768 pregnant women presenting for prenatal examination who were tested for serum 25OHD concentration during the second trimester between January 1, 2016, and December 31, 2020, were included in this retrospective analysis. Exposure to PM was evaluated based on daily average PM with an aerodynamic diameter of ≤ 2.5 µm (PM2.5) and PM with an aerodynamic diameter of ≤ 10 µm (PM10). Corresponding meteorological data for daily average atmospheric temperature, atmospheric pressure, relative humidity, sunshine duration, and wind speed were collected. The maximum cumulative effects of PM2.5 occurred at lag 45 days, and the maximum cumulative effects of PM10 occurred at lag 60 days. In crude models, 45-day moving daily average PM2.5 concentrations were negatively associated with 25OHD levels (ß, - 0.20; 95% CI - 0.21 to - 0.19), as were 60-day moving daily average PM10 concentrations (ß, - 0.14; 95% CI - 0.15 to - 0.14). After adjusting for temporal and meteorological factors, the effect values were drastically reduced (adjusted ß of PM2.5, - 0.032; 95% CI - 0.046 to - 0.018; adjusted ß of PM10, - 0.039; 95% CI - 0.049 to - 0.028). Our study showed there was a small, independent, negative association between PM in the atmosphere and maternal serum 25OHD levels during the second trimester of pregnancy after adjusting for temporal and/or meteorological factors, which indicates that PM may have a limited influence on maternal serum 25OHD levels. Besides taking vitamin D supplements, pregnant women should keep participating in outdoor activities while taking PM protection measures to improve their vitamin D levels when PM levels are high in winter and spring.

Cooking methods are associated with inflammatory factors, renal function, and other hormones and nutritional biomarkers in older adults.

Evidence of the role of cooking methods on inflammation and metabolic health is scarce due to the paucity of large-size studies. Our aim was to evaluate the association of cooking methods with inflammatory markers, renal function, and other hormones and nutritional biomarkers in a general population of older adults. In a cross sectional analysis with 2467 individuals aged ≥ 65, dietary and cooking information was collected using a validated face-to-face dietary history. Eight cooking methods were considered: raw, boiling, roasting, pan-frying, frying, toasting, sautéing, and stewing. Biomarkers were analyzed in a central laboratory following standard procedures. Marginal effects from generalized linear models were calculated and percentage differences (PD) of the multivariable-adjusted means of biomarkers between extreme sex-specific quintiles (Q) of cooking methods consumption were computed ([Q5 - Q1/Q1] × 100). Participants' mean age was 71.6 years (53% women). Significant PD for the highest vs lowest quintile of raw food consumption was - 54.7% for high sensitivity-C reactive protein (hs-CRP), - 11.9% for neutrophils, - 11.9% for Growth Differentiation Factor-15, - 25.0% for Interleukin-6 (IL-6), - 12.3% for urinary albumin, and - 10.3% for uric acid. PD for boiling were - 17.8% for hs-CRP, - 12.4% for urinary albumin, and - 11.3% for thyroid-stimulating hormone. Concerning pan-frying, the PD was - 23.2% for hs-CRP, - 11.5% for IL-6, - 16.3% for urinary albumin and 10.9% for serum vitamin D. For frying, the PD was a 25.7% for hs-CRP, and - 12.6% for vitamin D. For toasting, corresponding figures were - 21.4% for hs-CRP, - 11.1% for IL-6 and 10.6% for vitamin D. For stewing, the PD was 13.3% for hs-CRP. Raw, boiling, pan-frying, and toasting were associated with healthy profiles as for inflammatory markers, renal function, thyroid hormones, and serum vitamin D. On the contrary, frying and, to a less extent, stewing showed unhealthier profiles. Cooking methods not including added fats where healthier than those with added fats heated at high temperatures or during longer periods of time.

Assessing the effects of ultraviolet radiation, residential greenness and air pollution on vitamin D levels: A longitudinal cohort study in China.

Vitamin D metabolism is essential in aging and can be affected by multiple environmental factors. However, most studies conducted single exposure analyses. We aim to assess the individual and combined effects of ultraviolet (UV) radiation, residential greenness, fine particulate matter (PM2.5), and ozone (O3) on vitamin D levels in a national cohort study of older adults in China. We used the 2012 and 2014 Chinese Longitudinal Healthy Longevity Survey data, and measured the environmental exposure in the same year. We interpolated the UV radiation from monitoring stations, measured residential greenness through satellite-derived Normalized Difference Vegetation Index (NDVI), modeled PM2.5 with satellite data, and estimated O3 using machine learning. We dichotomized serum 25-hydroxy vitamin D (25(OH)D), the primary circulating form of vitamin D, into non-deficiency (≥50 nmol/L) and deficiency (<50 nmol/L) categories. We used the generalized estimating equation for analysis, adjusted for sociodemographic information, lifestyle, physical condition, and season of blood draw, and calculated joint odds ratios based on the Cumulative Risk Index. We also explored the interaction between interested exposures, modification of participants' characteristics, and potential mediation. We included 1,336 participants, with a mean age of 83 at baseline. In single exposure models, the odds ratios of vitamin D deficiency (VDD) for per interquartile range increase in UV radiation, NDVI, PM2.5, and O3 and decrease were 0.39 (95 % CI:0.33,0.46), 0.90 (0.81,1.00), 1.65 (1.53,1.78), 1.67 (1.46,1.92), respectively. UV radiation mediated nearly 48 % and 78 % of the relationship between VDD and PM2.5 and O3, respectively. The association between UV radiation and VDD was stronger in females than men (OR: 2.25 vs 1.22). UV radiation, residential greenness can protect against VDD, while, PM2.5 and O3 increase the risk of VDD. UV radiation partly mediated the association between air pollution and VDD.

Levels of Vitamin D and Expression of the Vitamin D Receptor in Relation to Breast Cancer Risk and Survival.

Previous research suggests associations between low systemic levels of vitamin D and poor breast cancer prognosis and between expression of the vitamin D receptor (VDR) in breast cancers and survival. This study aimed to study associations between pre-diagnostic systemic levels of vitamin D and expression of VDR in subsequent breast tumors, and interactions between vitamin D and VDR on breast cancer mortality. Systemic vitamin D levels were measured in women within the Malmö Diet and Cancer Study. The expression of VDR was evaluated immunohistochemically in a tissue microarray of subsequent breast cancers. Statistical analyses followed. Women with high levels of vitamin D had a smaller proportion of VDR negative breast tumors compared to women with low levels of vitamin D (odds ratio: 0.68; 95% confidence interval: 0.41-1.13). Vitamin D levels were not found to modify the association between low VDR expression and high breast cancer mortality. To conclude, there was no statistical evidence for an association between pre-diagnostic levels of vitamin D and the expression of VDRs in breast cancer, nor did vitamin D levels influence the association between VDR expression and breast cancer mortality. Further studies are needed in order to establish the effects of vitamin D on breast cancer.

A correlational analysis of COVID-19 incidence and mortality and urban determinants of vitamin D status across the London boroughs.

One of the biggest challenges of the COVID-19 pandemic is the heterogeneity in disease severity exhibited amongst patients. Among multiple factors, latest studies suggest vitamin D deficiency and pre-existing health conditions to be major contributors to death from COVID-19. It is known that certain urban form attributes can impact sun exposure and vitamin D synthesis. Also, long-term exposure to air pollution can play an independent role in vitamin D deficiency. We conducted a correlational analysis of urban form and air quality in relation to the demographics and COVID-19 incidence and mortality across 32 London boroughs between March 2020 and January 2021. We found total population, number of residents of Asian ethnicity, 4-year average PM10 levels and road length to be positively correlated with COVID-19 cases and deaths. We also found percentage of households with access to total open space to be negatively correlated with COVID-19 deaths. Our findings link COVID-19 incidence and mortality across London with environmental variables linked to vitamin D status. Our study is entirely based on publicly available data and provides a reference framework for further research as more data are gathered and the syndemic dimension of COVID-19 becomes increasingly relevant in connection to health inequalities within large urban areas.

Vitamin D Status among Women in a Rural District of Nepal: Determinants and Association with Metabolic Profile-A Population-Based Study.

Hypovitaminosis D is prevalent worldwide, and especially in South-Asia. According to the Institute of Medicine (IOM), 25(OH)D levels below 30 nmol/L are defined as vitamin D deficiency (VDD) and levels between 30−50 nmol/L as insufficiency (VDI). Besides its role in calcium homeostasis, it has been postulated that vitamin D is involved in metabolic syndrome. Given the scarcity of data on vitamin D status in Nepal, we aimed to examine the prevalence of VDD and VDI, as well as the determinants and association with metabolic parameters (lipids, HbA1c), in a cohort of women in rural Nepal. Altogether, 733 women 48.5 ± 11.7 years of age were included. VDD and VDI were observed in 6.3 and 42.4% of the participants, respectively, and the prevalence increased by age. Women reporting intake of milk and eggs > 2 times weekly had higher 25(OH)D levels than those reporting intake < 2 times weekly. Women with vitamin D levels < 50 nmol/L displayed higher levels of cholesterol, LDL-cholesterol, triglycerides, and HbA1c. Additionally, a regression analysis showed a significant association between hypovitaminosis D, dyslipidemia, and HbA1c elevation. In conclusion, VDI was prevalent and increased with age. Milk and egg intake > 2 times weekly seemed to decrease the risk of VDI. Moreover, hypovitaminosis D was associated with an adverse metabolic profile.

Effect of PM2.5 exposure on Vitamin D status among pregnant women: A distributed lag analysis.

BACKGROUND: Serum vitamin D levels are associated with exposure to air pollution, however, the lagged effect of exposure to air pollution remains unknown in pregnant women. METHODS: Pregnant women who delivered at a maternity center in Shanghai, China, from 2015 to 2019 were included in the present study. The concentration of particulate matter 2.5 (PM2.5) before 25-Hydroxyvitamin D [25(OH)D] detection was estimated using the satellite-based grid models. The distributed lag non-linear models were performed to examine the lagged association between weekly-specific PM2.5 exposure and vitamin D deficiency (VDD) or serum 25(OH)D levels. RESULTS: Among the 58,025 pregnant women included in the study (mean age at conception, 30.77 ± 3.75 years; mean prepregnancy BMI, 21.09 ± 2.55 kg/m2), 61.32% were diagnosed with VDD. Weekly-specific PM2.5 exposure at weeks 1-10 before the detection of 25(OH)D was significantly associated with an increased incidence of VDD (p < 0.05). For every 10 µg/m3 increase in PM2.5 exposure, the serum 25(OH)D level decreased by 1.346 nmol/L (95%CI: 1.183-1.508 nmol/L). The association between average PM2.5 exposure and VDD at 1-10 weeks was more significant in weather conditions with low mean sunshine hours (OR: 1.246, 95%CI: 1.221-1.271). CONCLUSION: Our study provided suggestive evidence that PM2.5 exposure at 1-10 weeks before the 25(OH)D detection may decrease the circulating 25(OH)D levels in pregnant women and increase VDD risk in pregnant women. More attention should be paid to the long-term impact of PM2.5, in particular, during weather conditions with a relatively short duration of sunshine.