Serum Vitamin Research Articles

The role of vitamin D in treated and refractory ulcerative colitis patients: a case-control study

BackgroundUlcerative colitis is a form of chronic inflammatory bowel disease (IBD) marked by ongoing inflammation of the mucosal lining that extends from the rectum to the upper part of the colon. Vitamin D regulates immune responses in several autoimmune and inflammatory diseases, including ulcerative colitis. Therefore, the study aims to investigate the role of vitamin D in the pathogenesis and treatment of ulcerative colitis.MethodsThis case-control study included 94 participants who were divided into four groups. Group 1: people with ulcerative colitis who responded to treatment (n = 24). Group 2: family members of patients who responded to treatment and did not have the disease (n = 24). Group 3: People with ulcerative colitis who are resistant to treatment (n = 23). Group 4: family members of treatment-resistant patients who does not have the disease (n = 23). Groups 1 and 3 were considered as patient groups (n = 47) and groups 2 and 4 as control groups (n = 47). Blood samples were taken and analyzed for complete blood count (CBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum vitamin D levels.ResultsThe mean age of treatment-responsive patients (group 1) was 45.88 ± 18.51 years, while treatment-resistant patients (group 3) averaged 41.30 ± 13.01 (P = 0.33) years. Serum Vitamin D levels were 24.96 ± 9.66 ng/mL in group 1 and 27.70 ± 12.28 ng/mL in group 3, showing no significant correlation with ulcerative colitis (P = 0.41). All groups had a BMI within the normal range, and mean CRP levels varied significantly across groups. Hemoglobin was significantly lower in group 3 compared to group 1 (P = 0.029), but ESR results showed no significant relationship with ulcerative colitis. Vitamin D levels were highest in patients with lower BMI, and no significant relationships were found between Vitamin D and other risk factors, although extensive colitis was associated with higher Vitamin D levels compared to distal colitis.ConclusionIn this study, there was no significant association between ulcerative colitis and serum levels of vitamin D. However, the small number of patients may limit the conclusions that can be drawn regarding the role of vitamin D in the treatment of ulcerative colitis. Future studies should aim for larger cohorts to provide more definitive insights into this important issue.

Serum Vitamin D Status Among Workers Coming from Middle East

Background: Vitamin D deficiency is common in the Middle East. To maintain health, vitamin D holds a very important place. Its deficiency is a major global health problem and affects both genders at all stages of life. Lack of exposure to sunlight is among the foremost causes of vitamin D deficiency. Methods: This hospital based cross sectional observational study carried out in the Department of Medicine in Comilla Medical College Hospital, Comilla, with a total of 100 cases purposively selected for the study. Detailed information was obtained in each individual according to protocol. Complete history was taken from patients. Thorough clinical examinations were done. Relevant investigations reports were collected. All the information was recorded in the fixed protocol. Collected data were classified, edited, coded and entered the computer for statistical analysis by using SPSS-23. Results: Out of 100 cases, 76.0% of participants belonged to age 21-40 years. The mean age was found 35.3±8.4 years with range from 18 to 62 years. Majority (95.0%) of participants were male with a ratio of 19:1. The majority (86.0%) of participants were exposed to sunlight ≤15 min/day. Only 3(3.0%) participants used sun block. More than three fourth (79.0%) of the participants used to eating sea fish (≥3 days per/weeks) followed by 52(52.0%) drink milk (≥3 days per/weeks) and 12(12.0%) was supplement with omega-3 fatty acid (fish oil). Majority 41(41.0%) of the participants had back pain followed by 12(12.0%) muscle cramp, 8(8.0%) neck pain and 8(8.0%) headache. Almost two third (65.0%) of the participants had deficiency, 31(31.0%) had insufficiency and 4(4.0%) had normal 25-hydroxyvitamin D. Significant association was also found between inadequate drinking milk with decreased 25-hydroxyvitamin D level. Conclusion: In conclusion 25-hydroxyvitamin D deficiency (65.0%) and insufficiency (31%) common among Bangladeshi workers coming from Middle East. It was influenced by their decreased sunlight exposure (≤15min/day) & clothing style. Inadequate consumption of milk and milk products may also play a role in decreasing vitamin D levels. J Rang Med Col. September 2024; Vol. 9, No. 2: 67-71

Case report: Vitamin B12 deficiency-associated hemolytic anemia

Vitamin B12 deficiency is commonly known to cause hematological, neurological, and gastrointestinal disturbances including anemia, pancytopenia, sub-acute combined degeneration, and glossitis, among others. Hemolytic anemia is a rare but possible presentation of vitamin B12 deficiency. We present a case series of three elderly females with different past medical histories but with similar presentations of severe anemia. Initial investigation revealed pancytopenia and hemolytic anemia. Further evaluation indicated vitamin B12 deficiency and subsequently, pernicious anemia, as confirmed by low serum vitamin B12 levels and positive intrinsic cell antibody respectively. These findings directed the diagnosis toward vitamin B12 deficiency-induced hemolytic anemia, a rare clinical entity. All three patients responded to treatment with intramuscular vitamin B12 injections, showing significant improvement in their pancytopenia and hemolytic anemia. This case series highlight the importance of considering vitamin B12 deficiency as a potential cause of hemolytic anemia in patients presenting with pancytopenia and ineffective hematopoiesis. Further research is necessary to illuminate the therapeutic implications of this rare condition.

Serum Vitamin D Levels in Patients with Vernal Keratoconjunctivitis: A Systematic Review and Meta-Analysis

ABSTRACT Purpose To conduct a systematic review and meta-analysis to provide an outline of available data on the association between serum vitamin D levels and vernal keratoconjunctivitis (VKC) and to determine the possible relationship in children. Methods Systematic research on all articles published until July 2023 was conducted in PubMed, SCOPUS, Web of Science, and Embase. All observational-analytical studies that measured vitamin D levels in patients with VKC were included. Extracted data were included in two separate meta-analyses: 1) a meta-analysis on the standardized mean difference (SMD) of vitamin D levels between VKC patients and the control group and 2) a meta-analysis on the prevalence of vitamin D deficiency in VKC patients. Results Seven relevant studies that included 316 patients, with the mean age of 10.8 3 ± 1.14 years, with VKC were included in this meta-analysis. The mean serum vitamin D level was significantly lower in the patients with VKC as compared with the control group (SMD: −0.92; 95% CI −1.15, −0.69, p < 0.001). The overall prevalence of vitamin D deficiency among VKC patients was 63.7% (95% CI 42.5%-80.7%, p < 0.001). VKC patients spent significantly less time outdoors during daylight compared to healthy individuals (SMD = −0.90, 95%CI −1.28, −0.52, p < 0.001). Conclusion VKC patients have lower serum vitamin D than healthy controls. This finding underscores the potential role of vitamin D in the immunopathogenesis of VKC.

No causal association between serum vitamin D levels and bronchiectasis: A Mendelian randomization analysis.

Observational studies have reported an association between Vitamin D deficiency and an increased risk of bronchiectasis. This study aims to investigate the causal relationship between Vitamin D levels and bronchiectasis using a 2-sample Mendelian randomization (MR) analysis. Data from 2 genome-wide association studies (GWAS) based on European ancestry were analyzed: serum vitamin D levels (sample size = 441,291 [UK Biobank]) and bronchiectasis (sample size = 187,830 [cases = 1107, controls = 186,723; FinnGen]). Inverse-variance weighted (IVW) analysis was primarily used to assess the causal effect of 25(OH)D levels on bronchiectasis, supplemented by Mendelian randomization Egger regression (MR-Egger), weighted median, simple mode, and weighted mode analyses. Additionally, MR-Egger intercept test and MR-Pleiotropy Residual Sum and Outlier methods were implemented to determine pleiotropy, and Cochran's Q test was conducted for heterogeneity testing. Leave-one-out analysis and Bayesian weighted Mendelian randomization was also used to assess the robustness of the results. The MR analysis suggested no significant causal effects of serum 25(OH)D levels on bronchiectasis using the IVW method (odds ratio = 1.550; 95% confidence interval [CI]: 0.908-2.315; P = .120). These results were consistent across MR-Egger regression, weighted median, simple mode, and weighted mode analyses. No significant heterogeneity, pleiotropy, or bias was detected in instrumental variables. Additionally, no evidence supported the causal effects of bronchiectasis on serum vitamin D levels (β = -0.002, 95% CI: -0.007 to 0.003; P = .463). Our study found no significant causal association between serum 25(OH)D levels and bronchiectasis, in either direction. A larger sample-sized randomized controlled trial (RCT) is needed to further investigate this potential causal relationship.

Vitamin A is associated with all-cause mortality in patients with chronic kidney disease: a population-based cohort study.

The association between serum vitamin A (VA) levels and outcomes in chronic kidney disease (CKD) patients remains unclear. This was a population-based cohort study. CKD participants from the National Health and Nutrition Examination Survey (NHANES) database were included for analysis. The primary outcome was all-cause mortality. Person correlation analysis and Cox regression models were used to assess the relation between serum VA levels and all-cause mortality among individuals with CKD. There were 689 participants included in this study. The serum VA level was 2.45 ± 1.06 μmol/L. The overall mortality was 43.69%. The participants in the nonsurvival group had higher serum VA levels than those in the survival group (2.18 ± 0.82 vs. 2.78 ± 1.24 μmol/L, p < 0.01). Serum VA concentrations were positively correlated with serum creatinine levels (r = 0.56, p < 0.01) and urea nitrogen (r = 0.58, p < 0.01) but negatively correlated with eGFR (r = -0.56, p < 0.01). The serum VA level was independently related to all-cause mortality (hazard ratio (HR) = 1.15, [95% CI: 1.01-1.31], p = 0.03). The Kaplan-Meier survival analysis suggested that the survival probability was lower in participants with serum VA levels exceeding 2.09 μmol/L than in participants with serum VA levels below 2.09 μmol/L (p < 0.0001). A high serum VA was independently related to all-cause mortality in CKD patients. VA requirements for patients with CKD is worth studies in the future.

The association of vitamin D with knee osteoarthritis pain: an analysis from the Osteoarthritis Initiative database

Knee osteoarthritis (KOA) is a major cause of disability in the elderly, with its pain primarily driving medical consultations. Despite numerous studies, the role of Vitamin D in managing KOA pain remains inconclusive. This study seeks to explore the association between serum Vitamin D levels and WOMAC pain scores, providing new insights into potential treatment strategies for KOA. Utilizing data from the Osteoarthritis Initiative (OAI) database, we conducted a cross-sectional analysis involving 524 participants. Serum levels of 25-hydroxyvitamin D were measured using liquid chromatography-tandem mass spectrometry. WOMAC pain scores served as the dependent variable. Multivariable linear regression models and restricted cubic splines were employed to assess the relationship between Vitamin D levels and KOA pain, with subgroup analyses stratified by sex. Higher Vitamin D levels were significantly associated with lower WOMAC pain scores in males across all models. For females, no significant associations were observed. The analysis suggests a nonlinear relationship between Vitamin D levels and KOA pain in the general cohort, which becomes non-significant after adjustment for covariates. Our findings indicate that Vitamin D is associated with reduced pain in male patients with KOA, highlighting a potential sex-specific therapeutic approach. The results warrant further investigation through longitudinal studies and randomized controlled trials to substantiate Vitamin D supplementation as a viable treatment for reducing KOA pain in males.

Serum concentrations of different or multiple vitamins and Sarcopenia risk among US adults: insights from NHANES

BackgroundThe relationship between serum concentrations of different or multiple vitamins and sarcopenia remains underexplored. This investigation evaluates potential links between serum concentrations of different or multiple vitamins and sarcopenia prevalence among adults in the United States.MethodsUtilizing a cross-sectional design, this research draws from the National Health and Nutrition Examination Survey (NHANES) dataset of 2003–2006, encompassing 5,060 participants with comprehensive serum vitamin A, E, B9, B12, C, and D concentrations, alongside sarcopenia and covariate measurements. Participant stratification into distinct vitamin co-exposure clusters was achieved through K-means clustering. Analytical models, including weighted logistic regression, restricted cubic splines (RCS), weighted quantile sum regression (WQS), quantile g-computation (Q-gcomp), and Bayesian kernel machine regression (BKMR), were employed to evaluate the association between serum concentrations of different or multiple vitamins and sarcopenia risk, with an emphasis on nonlinearity.ResultsIn this study, sarcopenia was detected in 681 individuals (13.46%). Logistic regression results did not demonstrate any linear association between individual vitamin levels and sarcopenia risk (PFDR > 0.05). Contrastingly, the RCS model unveiled significant non-linear relationships for vitamins A and D (P_non-linear < 0.05). The K-means clustering results showed that participants in high-level vitamin exposure group had lower sarcopenia risk compared with those in low-level vitamin exposure group (OR (95% CI): 0.582 (0.397, 0.852)). Additionally, higher serum concentrations of different or multiple vitamins correlated inversely with sarcopenia risk (P_trend = 0.002). This inverse association was corroborated by WQS, Q-gcomp, and theBKMR models and remained consistent upon sensitivity analysis.ConclusionsThis study elucidates an inverse correlation between serum concentrations of different or multiple vitamins and sarcopenia risk, emphasizing a non-linear association, particularly with suboptimal vitamin D concentrations. Given the limitations of the NHANES study, further researches are required to clarify the existence of these relationships.

Commentary: The roles of serum vitamin D and tobacco smoke exposure in insomnia: a cross-sectional study of adults in the United States.

Commentary: The roles of serum vitamin D and tobacco smoke exposure in insomnia: a cross-sectional study of adults in the United States.

Vitamin D deficiency in hip fracture patients is associated with an increased mortality risk

PurposeThe aims were to assess whether vitamin D deficiency influenced mortality risk and length of acute hospital stay in patients presenting with a hip fracture.MethodsA retrospective study was undertaken including all patients aged over 50 years that were admitted with a hip fracture to a single centre during a 24-month period. Serum vitamin D levels on admission, patient demographics, perioperative variables and mortality were collected. Cox regression analysis was utilised to determine the independent association between serum vitamin D levels and patient mortality.ResultsThe cohort consisted of 1510 patients with a mean age of 81.3 years and 1107 (71.4%) were female. 876 (58.0%) were vitamin D deficient (< 50 nmol/l). The median follow up was 405 (IQR 249 to 610) days. During follow-up there were 464 deaths (30.7%). Vitamin D deficiency was independently associated with higher mortality risk (hazard ratio [HR] 1.26, 95% confidence interval (CI) 1.03 to 1.53, P = 0.022). Male sex (HR 1.64, 95% CI 1.34 to 2.01, P < 0.001) was also associated with a higher mortality risk. Vitamin D deficiency was not associated with length of hospital stay (median difference 0 days, P = 0.207).ConclusionVitamin D deficiency was independently associated with increased mortality in hip fracture patients, though this finding may be influenced by lack of comprehensive adjustment for comorbidity. While the value of routine serum vitamin D measurement is debated, supplementation during hospital stays is important to reduce falls and fracture risks associated with deficiency.

Serum vitamin D concentration and anthropometric indicators of adiposity in adults without or with low dose statin users: a cross-sectional study

BackgroundThis study sought to determine the accuracy of several anthropometric parameters in association with serum Vit. D concentrations and to compare the novel indices with the conventional ones.MethodsA total of 947 individuals referred to the cardiology clinic who have not used statin or take low-dose statin were evaluated through a cross-sectional study. Data on demographic information, anthropometric indices, and biochemical measurements were gathered using a checklist. Both the multivariable regression modeling and the area under the receiver-operating characteristic (ROC) were employed for the analysis.ResultsConsidering novel indices, BRI (Body Roundness Index) showed the most powerful correlation with serum Vit. D levels among both genders. Among conventional ancient indices, WC (Waist Circumference) had the strongest association in both men and women groups. Based on the confounding factors-adjusted model, the highest odds ratio (OR) for the presence of Vit. D deficiency belonged to WHtR (Waist to Height Ratio) in women (OR, 0.347 (0.171–0.704), P = 0.003). None of the indices predicted Vit. D deficiency significantly among men. A Vit. D concentration of 4.55 ng/ml was found as a cutoff based on the metabolic syndrome status.ConclusionThe most powerful association with serum Vit. D levels were detected for BRI in both genders among newly developed indices. In addition, WHtR predicted Vit. D deficiency independent of confounding factors among women.

Pre-analytical stability of haematinics, lactate dehydrogenase and phosphate in whole blood at room temperature up to 24 h, and refrigerated serum stability of lactate dehydrogenase, folate and vitamin B12 up to 72 h using the CRESS checklist.

There is a lack of analyte stability data in whole blood (WB). The aim of this study was to determine the allowable delay in WB processing for lactate dehydrogenase (LDH), folate, vitamin B12, iron and phosphate measurement. The stability of LDH, folate and vitamin B12 was also assessed in stored serum at clinically relevant time points. Blood was taken from n=10 volunteers into Sarstedt serum gel tubes. We assessed stability in WB at room temperature up to 24 h, and stability in refrigerated serum up to 72 h. Mean percentage deviation at each time point was compared to criteria for minimum allowable bias. Results produced from one individual were removed due to discordant results, leaving n=9 specimens at each time point. Stability of folate and phosphate was variable in WB across 24 h, but was deemed to be clinically acceptable. LDH was unstable in WB, iron was stable for at least 12 h, and vitamin B12 and ferritin were acceptable for up to 24 h. Serum LDH, folate and vitamin B12 all demonstrated acceptable stability in refrigerated serum stored for up to 72 h. Blood should ideally be centrifuged within 7 h for phosphate, LDH and folate, and 12 h for iron. However, for phosphate, folate and iron, there is likely to be little clinical impact if serum separation is delayed up to 24 h. Further research is needed to assess LDH stability in WB at 0-12 h, but changes are minimal at 12 h. All other analytes assessed showed acceptable stability across the time-points tested.

Correlation between Vitamin D and Urine Microalbumin among Patients with Diabetic Nephropathy: A Cross-sectional Study

Introduction: Diabetic nephropathy is characterised by microalbuminuria (30-300 mg/day). Vitamin D is thought to affect pathophysiology of diabetes mellitus through vitamin D receptor activation or by regulating calcium homeostasis, thus contributing to development of diabetes mellitus and its complications in deficiency status. Aim: To study the relationship between vitamin D levels and urine microalbumin among individuals with type 2 diabetes mellitus, both with and without diabetic nephropathy. Materials and Methods: This was an analytical crosssectional study conducted in Department of Biochemistry and Nephrology, JJM Medical College, Davangere, Central Karnataka, India, between January 2019 and January 2020, involving 150 subjects: 50 with Type 2 Diabetes Mellitus (T2DM) without nephropathy, 50 with T2DM with nephropathy, and 50 healthy individuals. Glycaemic control of subjects was estimated using Glycosylated Haemoglobin (HbA1c), and renal damage was screened with serum creatinine, vitamin D, and urine microalbumin levels. The comparison of HbA1c, serum creatinine, microalbumin in urine, and vitamin D was analysed by Kruskal-Wallis test, while the association between vitamin D and HbA1c, and its correlation with microalbumin, was analysed by Spearman’s correlation. Results: The median age of controls and type 2 diabetics without nephropathy was 48 years, compared to 56 years among subjects with nephropathy, and the difference was statistically significant. A male preponderance was observed in all groups: 33 (66%) among type 2 diabetics without nephropathy, 34 (68%) among nephropathy subjects, and 36 (72%) among controls. The median concentrations of HbA1c, creatinine, and microalbumin were higher in diabetic nephropathy (8, 2.4, 140) compared to subjects without nephropathy (7, 1.16, 17) and controls (5.9, 1, 14). The median concentration of serum vitamin D was lower in diabetic nephropathy (12) compared to subjects without nephropathy (18) and controls (31). Furthermore, vitamin D and HbA1c were reciprocally related among diabetic nephropathy subjects (r=-0.61, p&lt;0.001). In contrast, HbA1c and microalbumin were positively correlated (r=0.73, p&lt;0.001). Conclusion: There is a substantial correlation between glycemic control, in the form of HbA1c and renal damage, in the form of microalbumin, and vitamin D levels. This justifies the inclusion of vitamin D as a potential new screening tool for diabetic nephropathy along with microalbumin.

Comment on: Serum vitamin D levels in children with vernal keratoconjunctivitis - A study from a tertiary care pediatric hospital of North India.

Comment on: Serum vitamin D levels in children with vernal keratoconjunctivitis - A study from a tertiary care pediatric hospital of North India.

Serum Vitamin D Profiles of Children with Asthma in Southwest Saudi: A Comparative Cross-Sectional Study

Serum Vitamin D Profiles of Children with Asthma in Southwest Saudi: A Comparative Cross-Sectional Study

AN OBSERVATIONAL STUDY OF PERIPHERAL NEUROPATHY IN DIABETES PATIENTS ON METFORMIN THERAPY AND THE ROLE OF VITAMIN B-12 SUPPLEMENTATION

Objective: This study aims to assess the prevalence of peripheral neuropathy in diabetic patients on metformin therapy using the Douleur Neuropathique 4 (DN-4) scale, explore the relationship between long-term metformin use and serum vitamin B-12 levels, and identify how metformin contributes to neuropathy. Additionally, it seeks to raise awareness about the importance of vitamin B-12 monitoring and supplementation for improving patient quality of life. Methods: An observational study was conducted involving diabetes patients on metformin therapy. Data were collected on patient demographics, clinical characteristics, and vitamin B-12 levels. Peripheral neuropathy was assessed using the DN-4 questionnaire. Correlations between metformin duration, dosage, vitamin B-12 levels, and neuropathy prevalence were analyzed. Results: The results indicated that the majority of the study population were male (61.2%) and aged 51-60 years (41.8%), with a majority proportion residing in urban areas (74%). A significant finding was that Peripheral neuropathy was prevalent in 44.8% of patients, with 51.5% exhibiting vitamin B-12 deficiency. Furthermore, the study identified a high prevalence of peripheral neuropathy with a significant correlation between longer metformin use and increased neuropathy (r =0.9372), additionally, a strong negative correlation between metformin dosage and Vitamin B-12 levels (r=-0.9189) highlighted the risk of deficiency with higher doses. Conclusion: The study underscores the critical role of monitoring and supplementing vitamin B-12 in diabetes patients on metformin therapy to mitigate peripheral neuropathy. Regular screening and proactive supplementation could potentially reduce neuropathic complications associated with long-term metformin use.

Prevalence of peripheral neuropathy in children with transfusion-dependent thalassemia: A hospital-based cross-sectional study

ABSTRACT Background: Our study aimed to determine the prevalence of Peripheral Neuropathy (using nerve conduction studies (NCS)) in children with transfusion-dependent thalassemia aged between 5 to 18 years and to study its correlation with chronic anemia, ferritin levels, chelation status, annual transfusion requirement, deficiency of serum Vitamin B12, and Folate levels. Methods: In this hospital-based cross-sectional study, 100 eligible children were enrolled in a tertiary care teaching hospital in New Delhi, India. Neurological examinations focusing on peripheral neuropathy followed by NCS were performed on all the patients. Age-wise cutoff values outside of 2.5 SD of normal were taken as abnormal. Results: None of the children had clinical features of peripheral neuropathy, although 77% had abnormalities in NCS. Of these, 33% had pure motor nerve changes, 7% had pure sensory nerve changes, 1% had abnormal F responses, and 26% had mixed nerve changes. These changes correlated significantly with chronic anemia and duration of iron chelation but not with other factors. Conclusion: In children with transfusion-dependent thalassemia who do not exhibit any neurological signs or symptoms, however, it is not uncommon to observe abnormal NCS at an average hemoglobin (Hb) level of less than 9.5 g/dl. Further comprehensive case-control studies are necessary to determine if a more specific Hb target range of 9.5 to 10.5 g/dl is appropriate and to investigate the potential impact of chelation therapy on these changes.

Sunscreen use associated with elevated prevalence of anti-nuclear antibodies in U.S. adults.

Antinuclear antibody (ANA) prevalence in the U.S. population increased from 1988 to 2012, especially in white and more educated individuals. In adults ages 20-39 years from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and 2011-2012, ANA prevalence was previously associated with urinary concentrations of a common sunscreen ingredient, benzophenone 3, measured in winter. Spot urines may not capture relevant chronic exposures, thus we examined whether ANA was related to sunscreen use. In a cross-sectional study of adults ages 20-59 (N=416 ANA positive, 2656 ANA negative, by Hep-2 immunofluorescence, 1:80 dilution), we examined associations of ANA with reported sunscreen use when in the sun for 1h or more. Logistic regression was used to calculate covariate-adjusted prevalence odds ratios (POR) and 95% Confidence Intervals (CI), overall and stratified by demographic factors, season, and vitamin D. We explored associations and joint effects with other sun protective behaviors and sunburn in the past 12 months. The association of ANA with sunscreen differed by age (interaction p=0.004): for ages 20-39, we saw an exposure response (POR 2.61, 95% CI 1.50, 4.24 for using sunscreen always or most of the time, and POR 1.85; 1.12, 3.05 for less frequent versus never-use; trend p<0.001). These associations were more apparent in females (interaction p=0.082), non-Hispanic white and black participants (vs. other race/ethnicity, interaction p=0.023), and those with sufficient serum vitamin D (≥50 vs. <50nmol/L, interaction p=0.001). ANA was not associated with other protective behaviors and not confounded or modified by these behaviors or recent sunburn. These cross-sectional findings showed frequent sunscreen was associated with ANA in younger adults, supporting the need for replication, and longitudinal studies with detailed exposure histories.

Enhanced Vitamin B12 Detection Using a CxNixOyFeyOx+3 Bimetal-Organic Framework: A Comprehensive Electrochemical Study

The functions of neurons and blood cells are aided by vitamin B12. Serum vitamin B12 levels are picomolar, and their deficiencies may be remedied using vitamin B12 tablets. Consequently, sensitive and selective vitamin B12 detectors that can be used at the point-of-care for food, pharmaceutical, and biological samples are urgently needed. In this study, we present the synthesis and carbonization of a Ni- and Fe-based bimetallic organic framework for the electrochemical sensing of vitamin B12. The crystalline nature and functional groups of the material were analyzed using X-ray diffraction and Fourier transform infrared (FT-IR) spectroscopy, and the oxidation states within the framework were determined using X-ray photoelectron analysis. Field-emission scanning electron microscopy revealed a uniform spherical morphology with particle sizes ranging from 2 to 10 nm. Electrochemical analysis was performed to detect vitamin B12 by cyclic voltammetry (CV) on a screen-printed carbon electrode modified with CxNixOyFeyOx+3. CV analysis revealed that the fabricated electrode exhibits excellent redox peaks at approximately 0.0245 and -0.514 V with a low detection limit of 49 nM for vitamin B12 and a wide linear detection range up to 200 µM. Interference studies confirmed the selectivity of the sensor with minimal impact from common biomolecules and inorganic ions. The sensor demonstrated excellent repeatability (RDS = 3.5%), reproducibility, and long-term stability, retaining 94% of its initial current response for over 20 d. The real sample analysis of commercial vitamin B complex tablets demonstrated a recovery rate of 98.59%, highlighting the practical applicability of the sensor in pharmaceutical analysis.

Causal association of serum vitamin D levels with urolithiasis: a bidirectional two-sample Mendelian randomization study.

In light of inconsistent evidence from previous observational studies regarding the correlation between serum vitamin D levels and urolithiasis, this study aimed to investigate the genome-wide causal association between genetically predicted serum 25(OH)D levels and urolithiasis using the Mendelian randomization (MR) approach. In this study, we utilized genome-wide association studies (GWAS) summary statistics from the UK Biobank and SUNLIGHT consortium for serum vitamin D levels, as well as urolithiasis data from FinnGen. We employed bidirectional two-sample MR analysis to evaluate potential causal relationships. The primary MR analysis relied on the inverse variance weighted (IVW) method, supplemented by MR-Egger, weighted median, and weighted mode approaches. Sensitivity analyses were conducted to ensure result robustness, including Cochran's Q test, MR-Egger intercept test, leave-one-out tests, and MR pleiotropy residual sum and outlier (MR-PRESSO) test. The MR analysis indicated no significant causal effects of serum 25(OH)D levels on urolithiasis [IVW method: (kidney and ureteral stones: OR = 1.134;95% CI, 0.953 to 1.350, p = 0.155; lower urinary tract stones: OR = 1.158; 95% CI, 0.806 to 1.666, p = 0.428)]. However, according to the IVW results, genetically predicted kidney and ureteral stones were associated with decreased serum 25(OH)D levels (beta = -0.025; 95% CI, -0.048 to -0.003; p = 0.028), while they did not indicate a causal effect of lower urinary tract stones on serum 25(OH)D levels (beta = -0.002; 95% CI, -0.013 to -0.008; p = 0.662). A sensitivity analysis suggested the robustness of these causal associations. Our MR study did not provide evidence supporting a causal association between serum 25(OH)D levels and urolithiasis among individuals of European descent. However, there might exist a negative causal association between kidney and ureteral stones and serum 25(OH)D levels.