Correlation between maternal and umbilical cord 25-hydroxy-vitamin D levels over a range of values. A prospective observational study from the United Arab Emirates.

Worldwide vitamin D insufficiency is remarkably prevalent in both children and adults, including pregnant women. The total amount of the vitamin is best measured by 25-hydroxy-vitamin D (25(OH)D), which is a measurement of total serum cholecalciferol 25(OH)D3 and ergocalciferol 25(OH)D2. There is a known correlation between maternal and umbilical cord blood (UCB) 25(OH)D; however, whether specific maternal demographics or comorbidities influence the correlation remains uncertain. This prospective observational study was designed to study if maternal 25(OH)D levels, maternal age and BMI, amount of supplementation, mode of delivery, diabetes, hypertension/preeclampsia, or sunlight exposure had an impact on the correlation. Women were enrolled in the study at admission to the labor ward. If they agreed to participate, venous blood was directly collected and analyzed for 25(OH)D. The UCB was sampled after delivery from the unclamped cord and immediately analyzed for 25(OH)D. ANOVA, Fisher's exact test, Pearson's correlation, and test of the differences between correlations using Fisher's z-transformation with Bonferroni correction were used accordingly. Of the 298 women enrolled, blood from both the mother and umbilical cord was analyzed successfully for 25(OH)D in 235 cases. The crude correlation between maternal and UCB 25(OH)D was very strong over all values of 25(OH)D (r = 0.905, R2 = 0.821, p <0,001) and remained strong independently of maternal demographics or co-morbidities (r ≥ 0.803, R2 ≥ 0.644, p <0.001). For women who delivered by caesarean section in second stage the correlation was strong (r ≥ 0.633, R2 ≥ 0.4, p <0.037). Test of differences between correlations showed significant stronger correlation in women with unknown 25(OH)D3 supplementation compared to women receiving 10.000 IU/week (p = 0.02) and 20.000IU/week (p = 0.01) and that the correlation was significantly stronger for women with a BMI of 25-29.9 compared to women with a BMI of <24.9 (p = 0.004) and 30-34.9 (p = 0.002). 213 (91%) women had lower 25(OH)D compared to the neonate, with a mean difference of -13.7nmol/L (SD = 15.6). In summary, the correlation between maternal and UCB 25(OH)D is very strong throughout low to high maternal levels of 25(OH)D with lower levels in maternal blood. Typical maternal demographics and comorbidities did not affect the transition.

Vitamin D status in active and inactive noninfectious uveitis - data from a reference university hospital in Rio de Janeiro, Brazil.

PURPOSE: This study aimed to investigate the correlation between serum vitamin D levels and disease activity in patients with noninfectious uveitis. METHODS: We conducted a prospective case-control study, assessing 51 patients with noninfectious uveitis, categorized into active (n=22) and inactive (n=29) groups, along with 51 healthy controls. Serum 25-hydroxy vitamin D [25(OH)D] levels were measured. The uveitis group also completed a questionnaire regarding sunlight exposure habits and vitamin D supplementation. RESULTS: Patients with inflammation-related uveitis exhibited low serum 25(OH)D levels in 68% of cases. The median 25(OH)D level in patients with active uveitis was 17.8 ng/mL (interquartile range [IQR], 15-21 ng/mL), significantly lower compared to the 31.7 ng/mL (IQR, 25-39 ng/mL) in patients with inactive uveitis (p<0.001) and the 27 ng/mL (IQR, 23-31 ng/mL) in the Control Group (p<0.001). Significantly, nearly all patients with uveitis taking vitamin D supplementation were in the Inactive Group (p<0.005). Moreover, reduced sunlight exposure was associated with active uveitis (p<0.003). Furthermore, patients with 25(OH)D levels below 20 ng/mL had ten times higher odds of developing active uveitis (p=0.001). CONCLUSIONS: This study revealed a prevalent 25(OH)D deficiency among patients with noninfectious uveitis and suggested a link between low 25(OH)D levels and disease activity. To prevent future episodes of intraocular inflammation, vitamin D supplementation and controlled sunlight exposure could be viable options.

Association between vitamin D deficiency and benign paroxysmal positional vertigo (BPPV) incidence and recurrence: a systematic review and meta-analysis.

OBJECTIVES: The objective of this study is to determine the relationship between serum vitamin D level and the risk of developing benign paroxysmal positional vertigo (BPPV) incidence and recurrence in countries in the Northern Hemisphere. DESIGN: Systematic review and meta-analysis. DATA SOURCES: PubMed, Scopus and Web of Science databases were searched for studies published between January 2000 and February 2023. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Participants located in the Northern Hemisphere aged 18 or over with at least one episode of BPPV, serum 25-hydroxyvitamin D levels measured and reported, no comorbidities or history of vitamin D supplementation. DATA EXTRACTION AND SYNTHESIS: Data extraction and synthesis were performed by a single reviewer and checked by a second reviewer. Inclusion and exclusion criteria and risk of bias were assessed by two independent reviewers using the Newcastle Ottawa Tool for Cohort studies and Risk of Bias Assessment Tool for Nonrandomised Studies checklist for case-control studies. Meta-analysis was conducted using random effects models. Standard mean difference with a 95% CI was used to measure the relationship between vitamin D level and BPPV. RESULTS: The 35 articles identified by the literature search reported data of 9843 individuals. 19 studies (7387 individuals) were included in the BPPV incidence meta-analysis while 7 studies (622 individuals) were included in the BPPV recurrence meta-analysis. Lower serum vitamin D levels were found in BPPV incidence compared with controls, but the relationship between vitamin D levels in recurrent BPPV compared with non-recurrent disease remained uncertain. CONCLUSION: Results of this systematic review and meta-analysis demonstrated a negative correlation between serum vitamin D and BPPV incidence, while any relationship between serum vitamin D and BPPV recurrence remained uncertain. Risk of bias analysis revealed evidence of variable quality. There were insufficient data available to evaluate seasonal relationships between serum vitamin D and BPPV. Given the potential for this as a confounding factor, future research should aim to investigate this further. PROSPERO REGISTRATION NUMBER: CRD42021271840.

Secondary hyperparathyroidism: Predictors and relationship with vitamin D status, bone turnover markers and bone mineral density.

INTRODUCTION: Secondary hyperparathyroidism (SHPT) has adverse implications for bone health but is relatively understudied. In this study we examine the prevalence and determinants of SHPT and describe the relationship of SHPT with bone turnover markers and bone mineral density (BMD) in older Irish adults. METHOD: Eligible participants (n = 4139) were identified from the Trinity-Ulster-Department of Agriculture (TUDA) study, a cohort of Irish adults aged ≥60 years. Exclusion criteria included an estimated glomerular filtration rate (eGFR) <30 ml/min and serum calcium >2.5 mmol/l to remove hyperparathyroidism due to advanced chronic kidney disease (CKD) and primary hyperparathyroidism respectively. The relationship between SHPT and bone turnover markers and BMD (measured by densitometry) was examined in a subsample (n = 1488). Vitamin D deficiency was defined as 25-hydroxyvitamin D [25 (OH)D] <30 nmol/l. RESULTS: Participants had a mean age of 73.6 ± 7.9 years, 65.1 % were female and 19.4 % were found to be vitamin D deficient. The prevalence of SHPT decreased as vitamin D increased, from 30.6 % in those deficient to 9.8 % in those with 25(OH)D ≥ 50 nmol/l and increased with declining kidney function. In non­calcium supplement users, principal determinants of SHPT were vitamin D deficiency (OR 4.18, CI 3.05-5.73, p < 0.001), eGFR 30-44 ml/min (OR 3.69, CI 2.44-5.57, p < 0.001), loop diuretic use (OR 3.52, CI 2.59-4.79, p < 0.001) and to a lesser extent body mass index (p = 0.001), eGFR 45-59 ml/min (p < 0.001) and 25(OH)D level 30-49 nmol/l (p = 0.002). Similar findings were observed in calcium supplement users, though proton pump inhibitors were also associated with SHPT (OR 1.55, CI 1.08-2.22, p = 0.018) while vitamin D 30-49 nmol/l was not. In participants with SHPT versus those without, bone turnover markers were higher: bone alkaline phosphatase (p = 0.017) and tartrate-resistant acid phosphatase (p = 0.033), whilst there was lower BMD at the neck of femur (0.880 vs. 0.903 g/cm2, p = 0.033) and total hip (0.968 vs. 0.995 g/cm2, P = 0.017). DISCUSSION: The results show that up to one in six older Irish adults had SHPT and this was associated with lower BMD and higher concentrations of bone turnover markers. Both vitamin D deficiency and 25(OH)D level 30-49 nmol/l were important predictors of SHPT. Loop diuretics and PPIs may also increase the risk of SHPT, and their use may need to be carefully considered in this population. Further studies examining the potential impact of these factors on bone health in similar populations to our study sample are warranted.

Accumulated LPS induced by colitis altered the activities of vitamin D-metabolizing hydroxylases and decreased the generation of 25-hydroxyvitamin D.

It is generally accepted that low vitamin D (VD) levels are associated with a high prevalence factor for Inflammatory bowel disease (IBD). IBD patients have observed higher levels of lipopolysaccharide (LPS), ALT, and AST than healthy people. Gut-derived LPS causes inflammatory injury in the liver and kidney. The VD-metabolizing mechanism is involved in the liver and kidney, which means IBD might impact VD metabolism. However, whether IBD affects VD metabolism has not been studied. In vitro LPS resulted in decreased CYP2R1 in liver cells as well as decreased CYP27B1 and increased CYP24A1 in kidney cells, revealing that LPS changed the activities of several hydroxylases. Mice with acute colitis had an increased LPS in serum and liver with mild hepatic injuries, while mice with chronic colitis had a significant elevation of LPS in serum, liver, and kidney with hepatorenal injuries. Thus, the liver hydroxylase for VD metabolism would be the first to be affected in IBD. Consequently, serum 25-hydroxyvitamin D declined dramatically with a significant elevation of 24,25-dihydroxyvitamin D and 1,24,25-trihydroxyvitamin D. Unchanged serum levels of 1,25-dihydroxyvitamin D might be the result of other factors in vivo. In acute colitis, a small dosage (4 IU/day) of cholecalciferol could protect the colon, decrease the serum level of LPS, and finally increase serum 25-hydroxyvitamin D. However, this improvement of cholecalciferol was fading in chronic colitis. These results suggested that VD supplementations for preventing and curing IBD in the clinic should consider hepatorenal hydroxylases and be employed as soon as possible for a better outcome.

Causal association between 25-Hydroxyvitamin D and risk of abnormal spermatozoa: A bidirectional Mendelian randomization study.

Previous studies indicated conflicting findings regarding the association between vitamin D and abnormal spermatozoa. Herein, we assessed the causal association between circulating 25-Hydroxyvitamin D (25OHD) levels and the risk of abnormal spermatozoa by utilizing bidirectional Mendelian randomization (MR) analysis. Genome-wide association study summary statistics for 25OHD and abnormal spermatozoa were obtained from publicly accessible databases. Single nucleotide polymorphisms (SNPs) associated with 25OHD and SNPs associated with abnormal spermatozoa were used as instrumental variables (IVs) for forward MR analysis and reverse MR analysis, respectively. Inverse variance weighted (IVW) was the main MR approach, while weighted median, MR-Egger, and maximum likelihood methods were employed to supplement IVW. In addition, several sensitivity tests assessed the reliability of MR analysis. Forward MR analysis showed that elevated 25OHD levels significantly reduced abnormal spermatozoa risk (odds ratio [OR] = 0.75, 95 % confidence interval [CI]: 0.56-1.00, P = 4.98E-02), and the effect remained statistically significant after excluding SNPs associated with confounders (OR = 0.73, 95 % CI: 0.54-0.98, P = 3.83E-02) or only utilizing SNPs located near 25OHD-associated genes only as IVs (OR = 0.58, 95 % CI: 0.41-0.81, P = 1.67E-03). Reverse MR analysis indicated abnormal spermatozoa not affecting 25OHD level (P > 0.05). Sensitivity tests showed that MR analyses were not affected by heterogeneity and horizontal polytropy. Overall, the present MR study supports that elevated 25OHD levels reduce the risk of abnormal spermatozoa. Therefore, ensuring adequate vitamin D intake and maintaining stable levels of 25OHD may be effective strategies to optimize reproductive outcomes.

Ambient ultraviolet-B radiation, supplements and other factors interact to impact vitamin D status differently depending on ethnicity: A cross-sectional study.

BACKGROUND & AIMS: Many determinants of vitamin D status have been well-described, yet supplementation guidelines largely follow a one-size-for-all model and deficiency remains common. We hypothesised that accounting accurately for ultraviolet-B (UVB) radiation and considering interactions could advance understanding of vitamin D status. METHODS: Asian, Black, and White participants from the UK Biobank cohort were included (N = 438,978). The Tropospheric Emission Monitoring Internet Service provided UVB data which we linked to participants' place of residence. UVB dose over 135 days prior to blood draw was weighted and added, yielding cumulative and weighted UVB (CW-D-UVB). The association between 25(OH)D and selected variables was assessed in multivariable linear regression models with and without interactions, stratified by ethnicity. Predictors were ranked using standardised ß-coefficients. RESULTS: Median 25(OH)D differed by ethnicity (Asian: 25.4 nmol/L (10.2 ng/mL), Black: 30.6 nmol/L (12.2 ng/mL), White: 47.9 nmol/L (19.2 ng/mL), p-value < 0.001). CW-D-UVB was strongly associated with 25(OH)D in all ethnicities. It was the most important predictor in White (ßAsian = 0.15, ßBlack = 0.20, ßWhite = 0.35), whereas supplementation was in Asian and Black participants (ßAsian = 0.30, ßBlack = 0.24, ßWhite = 0.21). We identified statistically significant interactions between BMI:supplementation (all), CW-D-UVB:sex (Asian and White), and CW-D-UVB:age (Black and White), and in White population between CW-D-UVB and supplementation, BMI, and cholesterol. CONCLUSION: Vitamin D deficiency was widespread, particularly among non-White individuals. UVB was a strong predictor of 25(OH)D and the effect was modified by other factors. Findings suggest that accurately measured ambient-UVB radiation and interactions could improve 25(OH)D prediction models, and support personalised approaches to vitamin D optimisation.

Factors to take into account when interpreting 25-hydroxy-vitamin D serum levels.

BACKGROUND: Assessing vitamin D status, typically evaluated using serum or plasma 25-hydroxy vitamin D [25(OH)D] concentration, is complex because of various influencing factors. METHODS: Seasonality significantly affects intra-individual variability in 25(OH)D levels. This variation can be addressed by employing cosinor functions that are tailored to the geographical location of the patient to correct for seasonal effects. In addition to seasonality, genetic factors, such as DBP polymorphism and body composition, particularly adiposity, play crucial roles. Dialysis patients with DBP 2-2 phenotype exhibit higher vitamin D requirements. Genotyping/phenotyping of DBP allows for better tailored vitamin D supplementation. The lipid-soluble nature of vitamin D also interacts with plasma components such as serum triglycerides, which can influence vitamin D measurements. Adiposity, which is negatively correlated with vitamin D concentration, necessitates body mass-based mathematical adjustments for accurate vitamin D assessment in subjects with extreme BMI values. CONCLUSIONS: Accordingly, vitamin D replacement therapy must be personalized, taking into account factors such as body size and seasonal variations, to effectively reach the target serum 25(OH)D concentrations.

Post-diagnosis serum 25-hydroxyvitamin D concentrations in women treated for breast cancer participating in a lifestyle trial in Italy.

OBJECTIVE: To report cross-sectionally serum levels of 25-hydroxyvitamin D [25(OH)D] in women living in Italy within 12 months from breast cancer (BC) diagnosis. METHODS: Baseline data were obtained from 394 women diagnosed with primary BC, enrolled from 2016 to 2019 in a lifestyle trial conducted in Italy. Subjects' characteristics were compared between two 25(OH)D concentrations (hypovitaminosis D<20 and ≥20 ng/mL) with the Chi-squared test or Fisher's exact test for small-expected counts. Using multiple logistic regression-adjusted models, we estimated odds ratios (ORs) of hypovitaminosis D with 95% confidence intervals (CIs) in the total sample and in the unsupplemented subgroup. RESULTS: Hypovitaminosis D was found in 39% of all subjects, 60% in unsupplemented subjects, and 10% in supplemented subjects. Increasing ORs of hypovitaminosis D were found with increasing body mass index, 25-30, >30, and ≥35 versus <25 kg/m2 (ORs: 2.50, 4.64, and 5.81, respectively, in the total cohort and ORs: 2.68, 5.38, and 7.08 in the unsupplemented); living in the most southern Italian region (OR 2.50, 95%CI 1.22-5.13); and with hypertriglyceridemia (OR 2.46; 95%CI 1.16-5.22), chemotherapy history (OR 1.86, 95%CI 1.03-3.38), and inversely with anti-estrogenic therapy (OR 0.43, 95%CI 0.24-0.75) in the total sample. CONCLUSIONS: Hypovitaminosis D in women recently diagnosed with BC and participating in a lifestyle trial in Italy was widespread and highest with obesity, hypertriglyceridemia, and chemotherapy use. Considering that hypovitaminosis D is a risk factor for lower efficacy of bone density treatments and possibly BC mortality, our results suggest the need to promptly address and treat vitamin D deficiency.

Serum 25-Hydroxyvitamin D Status and Vitamin D Supplements Use Are Not Associated with Low Back Pain in the Large UK Biobank Cohort.

Longitudinal studies assessing the association of vitamin D deficiency, defined by serum 25-hydroxyvitamin D levels < 30 nmol/L, and vitamin D supplement (VDS) use with low back pain (LBP) are sparse. This investigation assessed the cross-sectional and longitudinal association of vitamin D status and VDS use with LBP among 135,934 participants from the UK Biobank cohort. Approximately 21.6% of the participants had vitamin D deficiency, while only 4% regularly took VDS. In the month before study enrollment, 3.8% of the population reported experiencing LBP. An additional 3.3% of the population were diagnosed with LBP by their general practitioners for the first time during a median follow-up of 8.5 years. Vitamin D deficiency and VDS use were cross-sectionally associated with LBP in age- and sex-adjusted models, but these associations were not evident in comprehensively adjusted models. In longitudinal analyses, both vitamin D deficiency and VDS use were not associated with LBP in any model after correction for multiple testing. In conclusion, not unexpectedly due to the fact that LBP is multifactorial, our findings provide no evidence for the role of the vitamin D status in the etiology of LBP.

Association between serum 25-hydroxyvitamin D and vitamin D dietary supplementation and risk of all-cause and cardiovascular mortality among adults with hypertension.

BACKGROUND: The relationship between vitamin D status and mortality among adults with hypertension remains unclear. METHODS: This prospective cohort study involved a sample of 19,500 adults with hypertension who participated in the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2018. We utilized a weighted COX proportional hazard model to assess the association between vitamin D status and mortality. This statistical model calculates hazard ratios (HR) and their corresponding 95% confidence intervals (95% CI). RESULTS: The study indicated that lower serum 25(OH)D concentration was associated with an increased risk of all-cause mortality among individuals with hypertension. Specially. Those with concentrations between 25.0 and 49.9 nmol/L (HR = 1.71, 95%CI = 1.22-2.40) and less than 25.0 nmol/L (HR = 1.97, 95%CI = 1.15-3.39) had higher hazard ratios for all-cause mortality. Individuals with hypertension who took vitamin D supplements had a lower risk of all-cause mortality, but not the risk of CVD mortality (HR 0.75, 95%CI 0.54-1.03), compared to those who did not supplement (HR = 0.76, 95%CI = 0.61-0.94). Subgroup analysis further revealed that vitamin D supplementation was associated with a reduced risk of all-cause mortality among individuals without diabetes (HR = 0.65, 95%CI = 0.52-0.81) and individuals without CVD (HR = 0.75, 95%CI = 0.58-0.97), and a decreased risk of CVD mortality among individuals without diabetes (HR = 0.63, 95%CI = 0.45-0.88) and without CVD (HR = 0.61, 95%CI = 0.40-0.92). Furthermore, higher-dose vitamin D supplementation was also associated with a greater reduction in all-cause mortality among hypertensive individuals, and there was the potential synergistic effect of combining normal-dose calcium and vitamin D supplementation, showing a superior effect on mortality compared to low-dose supplementation in adults with hypertension. CONCLUSIONS: This prospective cohort study demonstrated a significant association between lower serum 25 (OH)D concentration and increased all-cause mortality among adults with hypertension. Furthermore, the study found that vitamin D supplementation had a strong and significantly positive correlation with reduced all-cause and CVD mortality among hypertensive individuals without diabetes or CVD. This positive correlation suggests that vitamin D supplementation could potentially be an effective strategy to reduce the risk of mortality in this specific group of people.

Vitamin D and behavioral disorders in older adults: results from the CLIP study.

OBJECTIVES: Vitamin D is involved in brain health and function. Our objective was to determine whether vitamin D deficiency was associated with behavioral disorders in geriatric patients. DESIGN: The observational cross-sectional CLIP (Cognition and LIPophilic vitamins) study. The report followed the STROBE statement. SETTING: Geriatric acute care unit in a tertiary university hospital in France for 3 months at the end of winter and beginning of spring. PARTICIPANTS: 272 patients ≥65 years consecutively hospitalized or seen in consultation. MEASUREMENTS: Participants were separated into two groups according to vitamin D deficiency (i.e., serum 25-hydroxyvitamin D ≤25 nmol/L). Behavior was assessed using the reduced version of the Neuropsychiatric Inventory Scale (NPI-R) score and subscores. Age, sex, BMI, education level, comorbidities, MMSE and GDS scores, use psychoactive drugs and vitamin D supplements, and serum concentrations of calcium, parathyroid hormone, TSH and estimated glomerular filtration rate (eGFR) were used as potential confounders. RESULTS: Participants with vitamin D deficiency (n = 78) had similar NPI-R score (17.4 ± 20.3 versus 17.2 ± 16.1, p = 0.92) but higher (i.e., worse) subscore of agitation and aggressiveness (2.0 ± 3.3 versus 1.2 ± 2.4, p = 0.02) and higher (i.e., worse) subscore of disinhibition (0.99 ± 2.98 versus 0.38 ± 1.42, p = 0.02) than those without vitamin D deficiency (n = 194). In multiple linear regressions, vitamin D deficiency was inversely associated with the subscore of agitation and aggressiveness (ß = 1.37, p = 0.005) and with the subscore of disinhibition (ß = 0.96, p = 0.008). CONCLUSION: Vitamin D deficiency was associated with more severe subscores of agitation and aggressiveness and of disinhibition among older adults. This provides a scientific basis to test the efficacy of vitamin D supplementation on behavioral disorders in older patients with vitamin D deficiency.

Effect of air temperature on serum 25-hydroxyvitamin D concentrations: A single institutional large-scale study in Korea.

Vitamin D deficiency is a worldwide health issue especially in women. Serum vitamin D concentrations vary depending on the weather. However, the ideal vitamin D supplementation strategy related to weather remains uncertain. We aimed to investigate the relationship between climate factors and serum 25-hydroxy vitamin D [25(OH)D] concentrations. This study included 11,272 women aged 20-79 who visited a health promotion center for annual checkups between January 2013 and December 2015. We reviewed medical records and collected daily meteorological data. We analyzed the association between serum 25(OH)D concentration and climate factors using simple and multiple regression models and then predicted serum 25(OH)D concentration using multiple fractional polynomial models. The median age of the participants was 51 years (20-79 years), and the mean serum 25(OH)D level was 17.4 ± 8.6 ng/mL. The serum 25(OH)D concentration was lower in young women than in older women. The proportions of women with adequate 25(OH)D levels were 14.9% and 47.0% in the age groups 20-29 and 70-79, respectively. The maximum level of predicted log 25(OH)D was found in September, and the minimum was found in January. In multiple regression analysis, age and monthly mean temperature were associated with 25(OH)D concentrations. Serum 25(OH)D level was predicted using the following formula: log (25(OH)D) = 2.144 + 0.009 × age + 0.018 × ((temperature + 12.4)/10)2 (P < 0.001, adjusted R2 = 0.091). Serum 25(OH)D concentrations changed according to air temperature. An adequate strategy for vitamin D supplementation, based on air temperature, is necessary to maintain healthy serum 25(OH)D levels.

Seasonal Variations in 25-Hydroxyvitamin D Levels among Pediatric Patients Attending the Healthcare Centre.

Vitamin D plays an essential role in maintaining bone density, building the immune system, and regulating cell growth alongside other key biological functions. Limited data are available about the seasonal variation in vitamin D levels in the pediatric population in Saudi Arabia. This study aimed to investigate the seasonal influence on the pediatric circulating levels of 25(OH)D. A total of 1790 pediatric outpatients who visited the University healthcare centre were included in this study. Overall, there was a noticeably high prevalence (69%) of both combined 25(OH)D deficiency and insufficiency. The highest mean serum concentration of 25(OH)D was recorded in summer (29 ng/mL) and autumn (27 ng/mL). The deficient and insufficient categories were predominant, accounting for 33% and 36%, respectively. Comparable patterns were recorded during autumn, winter, and spring. Interestingly, the 25(OH)D level was significantly associated with the four seasons (p = 0.001), with females having a higher prevalence of 25(OH)D deficiency in the spring and summer than males. Furthermore, only in autumn and winter, we found a significant association between gender and 25(OH)D status (p < 0.001 for both). Another association between nationality and the circulating levels 25(OH)D was found during autumn and winter (p < 0.001 and p = 0.01), respectively. In all seasons, age had a negative impact on serum (OH)D levels. However, this relationship was statistically significant (p < 0.05) only in summer, autumn, and winter. Gender was a significant predictor, with 25(OH)D levels in autumn and winter and an odds ratio of 1.67 in autumn and 2 in winter, indicating that being men had a positive influence on circulating 25(OH)D levels. There were highly significant differences in 25(OH)D concentrations among different age categories. The Saudi population experiences low levels of vitamin D, particularly in autumn and winter periods. This study showed that seasonality, age category, nationality, and gender influence vitamin D status, suggesting the need for tailored intervention and monitoring of 25(OH)D status to reach adequate levels of vitamin D. Healthcare practitioners and policymakers may consider the interplay between age, nationality, gender, and seasonal variations when addressing vitamin D status and a targeted supplementation approach for high-risk groups that may develop health issues.

Serum 25-hydroxyvitamin D mediates the association between heavy metal exposure and cardiovascular disease.

BACKGROUND: Mediation analysis aims to determine how intermediate variables affect exposure to disease. In this study, 25-hydroxyvitamin D (25(OH)D) was evaluated to assess its role in mediating heavy metal exposure and cardiovascular disease (CVD). METHODS: A total of 9,377 participants from the National Health and Nutrition Examination Survey (NHANES) for the years 2011-2018 were included. Firstly, restricted cubic spline (RCS), and multivariable logistic regression model were performed to estimate the association between heavy metal exposure (Cadmium, Lead, Mercury, Manganese, and Selenium), as well as serum 25(OH)D and CVD. Secondly, using generalized linear regression model and generalized additive models with smooth functions, we investigated the correlation between heavy metal exposure and serum 25(OH)D. Finally, the mediation effect of serum 25(OH)D in the associations between heavy metal exposure and CVD was explored. RESULTS: The RCS plots revealed that Cadmium, and Lead were positively and linearly associated with CVD, while Mercury, and Manganese were inversely and linearly associated with CVD. Additionally, a roughly L- and U-shaped relationship existed between Selenium, as well as 25(OH)D and CVD. When potential confounding factors were adjusted for, serum 25(OH)D had negative associations with Cadmium, Lead, and Manganese, while serum 25(OH)D had positive relationship with Selenium. There was a mediation effect between Manganese exposure and CVD, which was mediated by 25(OH)D. CONCLUSION: According to the mediation analysis, the negative association between Manganese exposure and incident CVD was increased by 25(OH)D. The increasing dietary intake of Vitamin D could increase the protective effect of manganese intake on CVD.

Association Between Serum 25-Hydroxyvitamin D and Trichomonas vaginalis Infection Among American Adults: NHANES 2013-2016.

BACKGROUND: Previous studies have suggested that vitamin D may possess anti-infection properties, but the relationship between vitamin D and Trichomonas vaginalis infection remains unexplored. METHODS: Using data from the National Health and Nutrition Examination Survey between 2013 and 2016, we conducted multivariate regression analyses and subgroup analyses to investigate the association between 25-hydroxyvitamin D (25[OH]D) levels and T. vaginalis infection, ensuring the robustness of our results. RESULTS: The final sample included data from 4318 individuals aged 20 to 59 years, among which 92 were diagnosed with T. vaginalis infection. For every 10 nmol/L increase in serum 25(OH)D level, there was a 22% reduction in the likelihood of T. vaginalis infection incidence (adjusted odds ratio [aOR], 0.78; 95% confidence interval [CI], 0.69-0.90). Similarly, higher concentration tertiles demonstrated relatively lower infection ratios compared with the tertile with the lowest 25(OH)D concentration (aOR, 0.54 [95% CI, 0.30-0.95; P = 0.030] for T2; aOR, 0.23 [95% CI, 0.09-0.61; P < 0.001] for T3). CONCLUSIONS: Our cross-sectional study indicates a negative association between 25(OH)D levels and the prevalence of T. vaginalis infection. However, further high-quality evidence is needed to establish a causal relationship between 25(OH)D levels and T. vaginalis infection, as well as to evaluate the potential role of vitamin D supplementation in preventing T. vaginalis infection.

Total and bioavailable 25-hydroxyvitamin D is not associated with improved sexual dysfunction following vitamin D supplementation in women with polycystic ovarian syndrome: a pilot study.

BACKGROUND: Vitamin D (Vit D) deficiency has been linked to symptoms of polycystic ovary syndrome (PCOS), yet little is known about Vit D supplementation as a treatment for sexual dysfunction (SDy) in women with PCOS. AIM: To explore the implications of serum total 25-hydroxyvitamin D (25[OH]D) and bioavailable 25[OH]D (bio-25[OH]D) status and replacement on women with PCOS and SDy. METHODS: Reproductive-age women with PCOS who were not desiring fertility were eligible provided that they also had SDy, as assessed by the Female Sexual Function Index (FSFI), and were without severe depression, as evaluated by the Beck Depression Inventory II (BDI-II). Participants were given the recommended dietary allowance of Vit D (600 IU daily) plus hormonal contraception (HC; cyclic ethinyl estradiol/drospirenone) or no HC for 6 months. Comparisons between groups were analyzed by chi-square test and t-test, and Pearson's correlation coefficient analyzed correlations between FSFI with demographics, BDI-II, androgen levels, and total and bio-25[OH]D. OUTCOMES: The outcomes included SDy (FSFI <26.55), total and serum bio-25[OH]D levels, and total and free testosterone. RESULTS: A total of 42 women without severe depression completed the FSFI, with 28 (66.7%) having SDy. All FSFI domains, including arousal, lubrication, orgasm, and pain, were significantly lower as compared with women without SDy, with no associations with respect to demographics, total and free testosterone, or total and bio-25[OH]D. Vit D replacement was initiated with HC (n = 18) or no HC (n = 10), and for those completing the study, FSFI improved (score >26.55) in 61% (11/18) regardless of the treatment group. A time-treatment effect showed a significant change for the domain of orgasm, suggesting that HC had more of an impact than Vit D replacement. Improvement in sexual function as a dichotomous variable was not associated with age, body mass index, other demographics, total and free testosterone, total and bio-25[OH]D, or HC use. CLINICAL IMPLICATIONS: Due to the prevalence of SDy in women with PCOS, efficacious treatment options are necessary. STRENGTHS AND LIMITATIONS: This study is the first to analyze the effect of Vit D supplementation on SDy in women with PCOS. Limitations included the small number of participants who completed the study, thus limiting meaningful conclusions and generalizability. CONCLUSION: Vit D status was not associated with SDy and BDI-II. While HC may have played a role, standard Vit D supplementation could not account for the noted improvement in FSFI in women with PCOS.

Effect of medium chain triglycerides enriched formula on growth of biliary atresia patients after Kasai portoenterostomy.

BACKGROUND AND STUDY AIMS: Biliary atresia (BA) is the most common cause of neonatal cholestasis, negatively affecting nutritional status, growth, and development. It is the most frequent paediatric indication for liver transplantation. The Kasai portoenterostomy (KPE) operation is an effective procedure with favourable outcomes when performed before two months of age. The present study aimed to assess the nutritional status of patients with biliary atresia who underwent the Kasai operation and to evaluate the effectiveness of nutritional counselling using medium-chain triglyceride (MCT) formulas and proper supplementation on their nutritional status, growth, and vitamin D levels. PATIENTS AND METHODS: This prospective observational study included 36 infants with biliary atresia who underwent Kasai portoenterostomy. All patients underwent clinical assessment, anthropometric evaluation, nutritional counselling, and an evaluation of vitamin D levels. Only compliant patients (22/36) were followed up after 3 and 6 months of nutritional counselling. RESULTS: Z-scores for weight, triceps skinfold thickness, and mid-upper arm circumference improved significantly after three months, and the height velocity Z-score improved after six months of nutritional counselling using an MCT-containing formula and supplementations. Patients who showed an improvement in cholestasis had better responses. The initial assessment revealed low serum levels of 25-hydroxyvitamin D in 77.8 %, which increased significantly (p = 0.012). CONCLUSION: Dietary intervention and supplementation with MCT and micronutrients can improve the nutritional status of children with BA following KPE.

Highly selective whole-cell 25-hydroxyvitamin D3 synthesis using molybdenum-dependent C25-steroid dehydrogenase and cyclodextrin recycling.

BACKGROUND: The global prevalence of vitamin D (VitD) deficiency associated with numerous acute and chronic diseases has led to strategies to improve the VitD status through dietary intake of VitD-fortified foods and VitD supplementation. In this context, the circulating form of VitD3 (cholecalciferol) in the human body, 25-hydroxy-VitD3 (calcifediol, 25OHVitD3), has a much higher efficacy in improving the VitD status, which has motivated researchers to develop methods for its effective and sustainable synthesis. Conventional monooxygenase-/peroxygenase-based biocatalytic platforms for the conversion of VitD3 to value-added 25OHVitD3 are generally limited by a low selectivity and yield, costly reliance on cyclodextrins and electron donor systems, or by the use of toxic co-substrates. RESULTS: In this study, we used a whole-cell approach for biocatalytic 25OHVitD3 synthesis, in which a molybdenum-dependent steroid C25 dehydrogenase was produced in the denitrifying bacterium Thauera aromatica under semi-aerobic conditions, where the activity of the enzyme remained stable. This enzyme uses water as a highly selective VitD3 hydroxylating agent and is independent of an electron donor system. High density suspensions of resting cells producing steroid C25 dehydrogenase catalysed the conversion of VitD3 to 25OHVitD3 using either O2 via the endogenous respiratory chain or externally added ferricyanide as low cost electron acceptor. The maximum 25OHVitD3 titer achieved was 1.85 g L-1 within 50 h with a yield of 99%, which is 2.2 times higher than the highest reported value obtained with previous biocatalytic systems. In addition, we developed a simple method for the recycling of the costly VitD3 solubiliser cyclodextrin, which could be reused for 10 reaction cycles without a significant loss of quality or quantity. CONCLUSIONS: The established steroid C25 dehydrogenase-based whole-cell system for the value-adding conversion of VitD3 to 25OHVitD3 offers a number of advantages in comparison to conventional oxygenase-/peroxygenase-based systems including its high selectivity, independence from an electron donor system, and the higher product titer and yield. Together with the established cyclodextrin recycling procedure, the established system provides an attractive platform for large-scale 25OHVitD3 synthesis.

The association between circulating 25-hydroxyvitamin D and pancreatic cancer: a systematic review and meta-analysis of observational studies.

PURPOSE: The relationship between circulating 25-hydroxyvitamin D [25(OH)D] and pancreatic cancer has been well studied but remains unclear. The purpose of this study was to elucidate the association between circulating 25(OH)D and pancreatic cancer by using a meta-analytic approach. METHODS: PubMed, Embase, and Wed of Science databases were searched through October 15, 2022. A random or fixed-effects model was used to estimate the pooled odds ratio (OR), risk ratio (RR), hazard ratio (HR) and their 95% confidence intervals (CIs). RESULTS: A total of 16 studies including 529,917 participants met the inclusion criteria, of which 10 reported incidence and 6 reported mortality. For the highest versus lowest categories of circulating 25(OH)D, the pooled OR of pancreatic cancer incidence in case-control studies was 0.98 (95% CI 0.69-1.27), and the pooled HRs of pancreatic cancer mortality in cohort and case-control studies were 0.64 (95% CI 0.45-0.82) and 0.78 (95% CI 0.62-0.95), respectively. The leave-one-out sensitivity analyses found no outliers and Galbraith plots indicated no substantial heterogeneity. CONCLUSION: Evidence from this meta-analysis suggested that high circulating 25(OH)D levels may be associated with decreased mortality but not incidence of pancreatic cancer. Our findings may provide some clues for the treatment of pancreatic cancer and remind us to be cautious about widespread vitamin D supplementation for the prevention of pancreatic cancer.