Tracking of serum 25-hydroxyvitamin D levels during 14 years in a population-based study and during 12 months in an intervention study

Serum 25-hydroxyvitamin D levels and risk of overall and site-specific cancers in Korean adults: results from two prospective cohort studies

BACKGROUND

The link between vitamin D and cancer remains inconclusive. In this study, we aimed to explore the relationship between circulating vitamin D levels and overall and site-specific cancers in Korean adults using data from two large prospective cohort studies.

METHODS

Baseline serum 25-hydroxyvitamin D [25(OH)D] levels were measured in a subset of participants from the Cardiovascular Disease Association Study (2005-2012) and the Health Examinees Study (2009-2013). We followed 46,514 adults aged ≥ 40 years who consented to linkage with national cancer registry data. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for cancer incidence according to quartiles of season-standardized 25(OH)D levels.

RESULTS

The median season-standardized 25(OH)D level was 45.6 nmol/L (interquartile range: 33.6-59.7 nmol/L). During the median follow-up of 10.6 years, 3,529 incident cancer cases were recorded. Compared with the first quartile, the upper quartiles of serum 25(OH)D were associated with a lower risk of overall cancer [HR (95% CI): 0.86 (0.77-0.95), 0.84 (0.75-0.93), and 0.80 (0.72-0.89), respectively; P for trend < 0.001]. For site-specific cancers, the HRs (95% CIs) for the comparison of extreme quartiles of serum 25(OH)D were 0.72 (0.52-0.99) for colorectal cancer, 0.32 (0.21-0.50) for liver cancer, and 0.75 (0.55-1.04) for lung cancer. Upon categorization of serum 25(OH)D levels based on absolute cut-off points, participants with levels ≥ 75 nmol/L had significantly lower risks of overall, liver, and lung cancers compared with those with levels < 30 nmol/L.

CONCLUSIONS

These findings suggest that higher 25(OH)D levels are associated with a lower risk of overall and some site-specific cancers in the Korean population.

CLINICAL TRIAL NUMBER

Not applicable.

Tracking of serum 25-hydroxyvitamin D levels over 11 years in the Norwegian HUNT study

BACKGROUND

Serum 25-hydroxyvitamin D (25(OH)D), a marker of vitamin D status influenced by sunlight exposure and diet, may affect various health conditions. This study investigates the tracking of serum 25(OH)D levels over 11 years in a general adult Norwegian population and identifies factors influencing future 25(OH)D levels.

METHODS

Serum 25(OH)D was measured in 3511 adults participating in both second and third surveys of the Trøndelag Health Study (HUNT2: 1995-1997, HUNT3: 2006-2008). Serum 25(OH)D was measured using a chemiluminescent assay and calibrated for batch effect and seasonal variation. Tracking was evaluated using correlation coefficients, intraclass correlation coefficient (ICC), and coefficient of variation (CV). Multivariable linear regression examined relations between factors in HUNT2 and 25(OH)D in HUNT3.

RESULTS

The correlation coefficient between 25(OH)D levels in HUNT2 and HUNT3 was 0.50 (95% CI: 0.47 to 0.52), with an ICC of 0.64 (95% CI: 0.56 to 0.70) and a CV of 18%. An average of 43% (range: 20.4%-54.9%) of participants remained in the same vitamin D category (<30.0, 30.0-49.9, 50.0-74.9 and ≥75.0 nmol/L) across both surveys. Male sex, vitamin D-decreasing polygenic score, higher body mass index and current smoking were associated with lower 25(OH)D levels, while higher education, moderate alcohol intake and vitamin D supplementation were associated with higher levels.

CONCLUSIONS

Serum 25(OH)D levels demonstrated moderate reliability over 11 years, suggesting that a single measurement may be insufficient for assessing long-term vitamin D status. Repeated measurements are recommended for accurate evaluation of vitamin D's role in chronic disease risk.

Cardiovascular disease outcomes in relation to 25-hydroxyvitamin D and its seasonal variation: Results from the BiomarCaRE consortium

BACKGROUND

It has been hypothesized but seldom tested that the winter excess in cardiovascular disease (CVD) is related to hypovitaminosis D. The present study examined the association between CVD and (i) seasonality of 25-hydroxyvitamin D (25[OH]D) and (ii) individual 25(OH)D concentrations.

METHODS AND FINDINGS

Harmonized 25(OH)D data were obtained from the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE) project, including 79,570 participants examined between 1984 and 2010. One 25(OH)D measurement was available per participant. Primary endpoints were CVD incidence (coronary heart disease or stroke; n = 6006) and CVD mortality (n = 2985). To study (i), Poisson regression-derived rate ratios were compared according to two-month categories, ordered by baseline 25(OH)D concentrations. To study (ii), Cox regression-derived hazard ratios were compared according to quarters of baseline 25(OH)D concentrations. With respect to (i), despite a median 25(OH)D concentration ratio of 1:1.79, the trough months of 25(OH)D in March and April had a similar CVD incidence as the peak months of 25(OH)D in August and September (rate ratio: 1.07, 95% CI: 0.98-1.17). CVD mortality was slightly higher in the trough months compared to the peak months (rate ratio: 1.27, 95% CI: 1.12-1.44) but not compared to the other months (despite median 25[OH]D concentration ratios up to 1:1.62; p ≥ 0.077). The CVD mortality peak in January preceded the 25(OH)D trough, not adhering to the temporality criterion of Bradford Hill. With respect to (ii), compared to the lowest quarter, the highest quarter of 25(OH)D was associated with lower CVD incidence (hazard ratio: 0.82, 95% CI: 0.76-0.89) and CVD mortality (hazard ratio: 0.64, 95% CI: 0.57-0.72).

CONCLUSION

The present study does not support the hypothesis that seasonal increases in CVD are driven by short-term reductions in 25(OH)D. As in most observational studies, higher 25(OH)D concentrations were inversely associated with CVD.

Vitamin D: Evidence-Based Health Benefits and Recommendations for Population Guidelines

Vitamin D offers numerous under-recognized health benefits beyond its well-known role in musculoskeletal health. It is vital for extra-renal tissues, prenatal health, brain function, immunity, pregnancy, cancer prevention, and cardiovascular health. Existing guidelines issued by governmental and health organizations are bone-centric and largely overlook the abovementioned extra-skeletal benefits and optimal thresholds for vitamin D. In addition, they rely on randomized controlled trials (RCTs), which seldom show benefits due to high baseline 25-hydroxyvitamin D [25(OH)D] concentrations, moderate supplementation doses, and flawed study designs. This review emphasizes the findings from prospective cohort studies showing that higher 25(OH)D concentrations reduce the risks of major diseases and mortality, including pregnancy and birth outcomes. Serum concentrations > 30 ng/mL (75 nmol/L) significantly lower disease and mortality risks compared to <20 ng/mL. With 25% of the U.S. population and 60% of Central Europeans having levels <20 ng/mL, concentrations should be raised above 30 ng/mL. This is achievable through daily supplementation with 2000 IU/day (50 mcg/day) of vitamin D3, which prevent diseases and deaths. Furthermore, a daily dose between 4000 and 6000 IU of vitamin D3 to achieve serum 25(OH)D levels between 40 and 70 ng/mL would provide greater protection against many adverse health outcomes. Future guidelines and recommendations should integrate the findings from observational prospective cohort studies and well-designed RCTs to improve public health and personalized care.

Relationship of Serum 25-Hydroxyvitamin D Concentrations, Diabetes, Vitamin D Receptor Gene Polymorphisms and Incident Venous Thromboembolism

AIMS

The association between vitamin D and the risk of venous thromboembolism (VTE) remains inconclusive. We aimed to explore the association of serum 25-hydroxyvitamin D (25OHD) with incident VTE among participants with and without diabetes, and examine the modifying effect of genetic susceptibility of VTE and vitamin D receptor (VDR) gene polymorphisms on this association.

MATERIALS AND METHODS

A total of 378,082 participants free of VTE at baseline from the UK Biobank were included. Serum 25OHD concentrations were measured by the chemiluminescent immunoassay method. The primary outcome was incident VTE, including deep vein thrombosis (DVT) and pulmonary embolism (PE). The genetic risks of VTE were estimated using 297 single nucleotide polymorphisms (SNPs) associated with VTE. The VDR gene polymorphisms included SNPs of rs7975232, rs1544410, rs2228570 and rs731236.

RESULTS

During a median follow-up duration of 12.5 years, 10,645 VTE cases were recorded. Serum 25OHD had a significantly stronger inverse association with incident VTE in participants with diabetes (per SD increment, adjusted HR: 0.87; 95% CI: 0.81-0.93) than in those without diabetes (per SD increment, adjusted HR: 0.97; 95% CI: 0.95-0.99; p-interaction = 0.003). Similar trends were found for incident DVT and PE. Among participants with diabetes, the genetic risk of VTE did not significantly modify the association between serum 25OHD and incident VTE (p-interaction = 0.607). However, a stronger inverse association of serum 25OHD with incident VTE was found in the VDR rs2228570 AA genotype (vs. GG/AG; p-interaction = 0.031).

CONCLUSIONS

Serum 25OHD was inversely associated with the risk of VTE, especially among participants with diabetes, regardless of genetic risks of VTE.

Vitamin D binding protein genetic isoforms, serum vitamin D, and cancer risk in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial

Associations between vitamin D biochemical status and cancer may be modified by vitamin D binding protein isoforms which are encoded by GC (group-specific component). We examined interactions between serum 25-hydroxyvitamin D [25(OH)D], the Gc isoforms Gc1-1, Gc1-2, and Gc2-2, and cancer risk within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial cohort based on 3,795 cases and 3,856 controls. Multivariable-adjusted logistic regression models estimated odds ratios (ORs) and 95% confidence intervals (CIs) of cancer risk according to 25(OH)D quantiles, stratified by Gc isoform. Separately, the GC-cancer risk association was examined using proportional hazards regression among 109,746 individuals with genetic data and 26,713 diagnosed with cancer. Specific vitamin D binding protein isoform subtypes were delineated and analyzed, including Gc1-1 subtypes (Gc1s-Gc1s, Gc1f-Gc1s, and Gc1f-Gc1f) and Gc2 subtypes (Gc1s-Gc2, Gc1f-Gc2, and Gc2-Gc2). For most cancers, the GC genotype did not modify the risk associations for 25(OH)D; e.g., the OR for high vs. low vitamin D quintile was 1.09 (0.89-1.33) for overall cancer risk among individuals with the Gc1-1 isoform and 1.04 (0.83-1.31) among those with either the Gc1-2 or Gc2-2 isoforms. ORs for high compared to low vitamin D tertile for colorectal, lung, breast, and prostate cancer among those with the Gc1-1 vs. any Gc2 isoforms were, respectively, 0.60 vs. 0.73, 1.96 vs. 1.03, 1.30 vs. 1.18, and 1.19 vs. 1.22 (all p-interaction ≥0.36). However, GC qualitatively modified the vitamin D-bladder cancer risk association: OR = 1.70 (95% CI 0.96-2.98) among those with the Gc1-1 isoform and 0.52 (0.28-0.96) among those with any Gc2 isoforms (p-interaction = 0.03). When modeled without regard for 25(OH)D, Gc isoforms were generally not associated with cancer risk, although melanoma risk was significantly lower among individuals with the "f" subtype of the Gc1-1 isoform, specifically HR = 0.83 (95% CI 0.70-0.98) for Gc1f-1s and 0.67 (0.45-1.00) for Gc1f-1f, compared to individuals with the Gc1s-Gc1s isoform. Vitamin D binding protein genetic isoforms may be associated with melanoma risk but do not modify the association between vitamin D status and cancer, with the possible exception of bladder cancer.

How Follow-Up Period in Prospective Cohort Studies Affects Relationship Between Baseline Serum 25(OH)D Concentration and Risk of Stroke and Major Cardiovascular Events

Background/Objectives: Prospective cohort studies are useful for studying how biomolecular status affects risk of adverse health outcomes. Less well known is that the longer the follow-up time, the lower the association (or "apparent effect") due to "regression dilution". Here, we evaluate how follow-up interval from baseline to "event" affects the relationship between baseline serum 25-hydroxyvitamin D [25(OH)D] concentration and the later incidence of stroke and major cardiovascular events (MACEs). Methods: Findings for the relative risk (RR) of stroke and MACEs with respect to serum 25(OH)D concentrations at baseline from prospective cohort studies were plotted against mean follow-up time. Fifteen studies from mainly European countries and the United States were used for stroke and nine studies for MACEs. Linear regression analyses were used to study data for follow-up periods of up to 10 years and for more than 10 years. Results: For stroke, the linear regression fit for 1-10 years is RR = 0.34 + (0.065 × follow-up [years]), r = 0.84, adjusted r2 = 0.67, p < 0.001. No significant variations in association were found for studies with follow-up periods of 10-20 years. For MACEs, the linear fit for 1-8.1 years is RR = 0.61 + (0.055 × follow-up [years]), r = 0.81, adjusted r2 = 0.59, p = 0.03. Discussion: The shorter the follow-up period, the greater the apparent effect of better vitamin D status in reducing risk of stroke and MACEs. In addition, the apparent effect of higher 25(OH)D concentration found for the shortest follow-up time is more than twice as great as the estimate based on average follow-up intervals for all studies. Mechanisms have been found to explain how higher serum 25(OH)D concentrations could reduce risk of stroke and MACEs. Randomized controlled trials have not shown that vitamin D supplementation significantly reduces risk of either stroke or MACEs, probably because risk of both outcomes increases rapidly below 15 ng/mL (38 nmol/L) and it is difficult in Western developed countries to enroll enough participants with concentrations that low. Nonetheless, vitamin D's role in reducing risk of stroke and MACEs could be considered causal on the basis of an evaluation of the evidence using Hill's criteria for causality in a biological system. Conclusions: Serum 25(OH)D concentrations above 20 ng/mL are associated with significantly reduced risk of stroke and MACEs prospectively and in an apparent causal manner. Raising serum 25(OH)D concentrations to >20 ng/mL should, therefore, be recommended for everyone likely to be at risk for stroke or MACEs and indeed in the general population.

Association between serum 25-hydroxyvitamin D concentrations and kidney stone: a cohort study in the UK Biobank

OBJECTIVE

To investigate the association between serum 25(OH)D and kidney stone disease (KSD) in participants from the UK Biobank.

METHODS

We used data from the UK Biobank. Our analysis involved Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) to estimate the association between serum 25(OH)D levels (measured at the time of recruitment) and the risk of KSD, which was determined using hospital records.

RESULTS

This study involved 444,343 participants, with 4,458 cases of KSD identified during an average follow-up period of 12.6 years. Higher 25(OH)D levels were not associated with developing kidney stones in general population model 3 (HR = 0.88 [95% CI 0.77-1.01]). Interestingly, higher serum 25(OH)D concentrations in women over 60 years old were associated with a lower risk of kidney stone disease. The multivariate HRs and 95% CIs for participants who had serum 25(OH)D ≥ 50 nmol/L or ≥ 75 nmol/L, compared with those who were severely deficient (25[OH]D < 25 nmol/L), were 0.74 (0.58-0.95), 0.60 (0.43-0.85) for KSD, respectively (P for trend < 0.01). However, this trend was not statistically significant in the subgroup analysis of serum calcium ion concentration.

CONCLUSION

High 25(OH)D levels were not associated with a higher incidence of kidney stones if serum calcium levels are within a normal range. The findings alleviate physiological concerns regarding the supplementation of vitamin D alone to raise serum 25(OH)D concentration.

Association of serum 25-hydroxyvitamin D with cardiovascular mortality and kidney outcome in patients with early stages of CKD

PURPOSE

While serum 25-hydroxyvitamin D (25[OH]D) deficiency is prevalent in chronic kidney disease (CKD), the effects of 25(OH)D deficiency on cardiovascular mortality and kidney outcomes in patients with early-stage CKD remain incompletely understood.

METHODS

This multicenter retrospective cohort study included adult patients with stages 1-3 CKD from 19 medical centers across China between January 2000 and May 2021. The primary outcome was cardiovascular mortality. The secondary study outcome included CKD progression (defined as a sustained > 40% eGFR decrease from baseline or progress to end-stage kidney disease), and annual percentage change of eGFR.

RESULTS

Of 9229 adults with stages 1-3 CKD, 27.0% and 38.9% had severe (< 10 ng/mL) and moderate (10 to < 20 ng/mL) serum 25(OH)D deficiency, respectively. Compared with patients having 25(OH)D ≥ 20 ng/mL, a significantly higher risk of cardiovascular mortality (hazard ratio [HR] 1.90, 95% CI 1.37-2.63), CKD progression (HR 2.20, 95% CI 1.68-2.88), and a steeper annual decline in eGFR (estimate - 7.87%; 95% CI - 10.24% to - 5.51% per year) was found in those with serum 25(OH)D < 10 ng/mL. Similar results were obtained in subgroups and by sensitivity analyses.

CONCLUSIONS

25(OH)D deficiency is associated with increased risks of cardiovascular mortality and CKD progression in patients with early-stage CKD. Studies are needed to determine whether early intervention for 25(OH)D deficiency could improve the prognosis of patients with early-stage CKD.

Follow-Up Period Affects the Association between Serum 25-Hydroxyvitamin D Concentration and Incidence of Dementia, Alzheimer's Disease, and Cognitive Impairment

BACKGROUND/OBJECTIVES

Vitamin D's effect on risk health outcomes is often evaluated using prospective cohort studies. For vitamin D, risk ratios (RRs) are based on health outcomes with respect to serum 25-hydroxyvitamin D [25(OH)D] concentrations measured at time of enrollment. Serum 25(OH)D concentrations vary over time, thereby diluting the effect of 25(OH)D for long follow-up periods. Inverse relationships between RR and follow-up period have been reported for all-cause mortality rate and cancer incidence rates. Here, the effect for neurological outcomes is evaluated.

METHODS

The analysis examines how follow-up period affected results from nine cohort studies of all-cause dementia, six studies of Alzheimer's disease, and nine for cognitive impairment with respect to vitamin D deficiency.

RESULTS

For all-cause dementia, Alzheimer's disease, and cognitive impairment, respectively, the linear regression fits are RR = 2.9 - 0.14 × years, r = 0.73, p = 0.02; RR = 2.9 - 0.14 × years, r = 0.69, p = 0.13; and RR = 1.8 - 0.066 × years, r = 0.72, p = 0.03. The regression fit to RR for the shortest follow-up period for each outcome is considered the best estimate of vitamin D deficiency's effect on risk. Those values are approximately twice that found by averaging all RRs without considering the effect of follow-up period.

CONCLUSIONS

Vitamin D's effect on risk of neurological conditions is inversely correlated with mean follow-up period in prospective cohort studies. This effect should be considered in the design and analysis of such studies. Additional studies should also be conducted regarding raising serum 25(OH)D concentrations to reduce risk of brain function decline.

Circulating 25-hydroxyvitamin D concentration can predict bowel resection risk among individuals with inflammatory bowel disease in a longitudinal cohort with 13 years of follow-up

BACKGROUND

Although the beneficial properties of vitamin D in anti-inflammation and immunity-modulation are promising in the management of inflammatory bowel disease (IBD), data were limited for the critical IBD prognosis. The association between serum vitamin D levels and the risk of bowel resection in individuals with IBD remains largely unknown.

MATERIALS AND METHODS

The authors performed a longitudinal cohort study among 5474 individuals with IBD in the UK Biobank. Serum 25-hydroxyvitamin D [25(OH)D] was measured using direct competitive chemiluminescent immunoassay. Bowel resection events were ascertained via national inpatient data. Multivariable-adjusted Cox proportional hazard regression was used to examine the association between serum 25(OH)D and bowel resection risk, presented with hazard ratios (HRs) and 95% CIs. Restricted cubic spline (RCS) was used to evaluate dose-response associations.

RESULTS

During a mean follow-up of 13.1 years, the authors documented 513 incident bowel resection cases. Compared to participants with vitamin D deficiency, nondeficient participants showed a significantly reduced bowel resection risk in IBD (HR 0.72, 95% CI: 0.59-0.87, P =0.001), Crohn's disease (CD, HR 0.74, 95% CI: 0.56-0.98, P =0.038), and ulcerative colitis (UC, HR 0.73, 95% CI: 0.57-0.95, P =0.020). When comparing extreme quintiles of 25(OH)D level, participants with IBD showed a 34% reduced risk of bowel resection (95% CI: 11-51%, P =0.007) and participants with UC showed a 46% reduced risk (95% CI: 19-64%, P =0.003), while this association was not significant in CD (HR 0.93, 95% CI: 0.59-1.45, P =0.740). Linear dose-response associations were observed using the RCS curve (all P -nonlinearity>0.05).

CONCLUSION

Increased serum level of 25(OH)D is independently associated with reduced bowel resection risk in IBD. This association was significant in UC but may not be stable in CD. Vitamin D deficiency is a risk factor for bowel resection in individuals with IBD, and may be an effective metric in predicting and risk-screening surgical events.

Nonlinear correlation and mediation effects between serum 25-hydroxyvitamin D levels and all-cause mortality in COPD patients

Background

Numerous studies have shown that low levels of vitamin D are linked to a higher risk of inflammatory diseases and their progression. However, how vitamin D levels affect mortality in chronic obstructive pulmonary disease (COPD) patients is still unclear. Thus, this study aimed to explore the relationship between serum 25-hydroxyvitamin D [25(OH)D] levels and the risk of death from all causes in U.S. adults with COPD.

Methods

This study analyzed 1,876 adults with COPD from the National Health and Nutrition Examination Survey (2005-2018). Mortality data up to December 31, 2019, were obtained from the National Death Index (NDI) records. Participants were categorized into three groups according to their 25(OH)D levels: Q1 (<50.0 nmol/L) for deficiency; Q2 (50.0-74.9 nmol/L) for insufficiency; and Q3 (≥75.0 nmol/L) for adequacy. A weighted Cox regression model assessed the link between 25(OH)D levels and mortality. Kaplan-Meier survival curves, subgroup, and sensitivity analyses were conducted. Additionally, the relationship between 25(OH)D and the hazard ratio (HR) was detailed through restricted cubic spline analysis. Mediation analysis revealed how 25(OH)D mediates the relationship between Dietary Inflammatory Index and mortality.

Results

There were 395 all-cause deaths during the follow-up, resulting in a mortality rate of 21.06%. After adjusting for potential confounders, higher 25(OH)D levels significantly correlated with a lower risk of all-cause mortality in COPD patients (HR = 0.52, 95% CI: 0.37-0.72, p < 0.001). Restricted cubic spline analysis indicated a non-linear relationship between 25(OH)D levels and all-cause mortality (p for nonlinear = 0.023), with levels below 63.4 nmol/L posing an independent risk for all-cause mortality in COPD patients (HR = 0.98, 95% CI: 0.97-0.99, p = 0.005). Sensitivity and subgroup analyses confirmed our results' robustness, with mediation analysis showing 25(OH)D's 22% mediating effect on diet-induced inflammation and all-cause mortality in COPD patients.

Conclusion

25(OH)D independently lowers the risk of all-cause mortality in COPD patients, with a non-linear L-shaped correlation, and mediates the effect of Dietary Inflammatory Index on mortality, suggesting new therapeutic possibilities.

Vitamin D and Risk of Incident Type 2 Diabetes in Older Adults: An Updated Systematic Review and Meta-Analysis

Vitamin D deficiency is very common worldwide, particularly in old age, when people are at the highest risk of the negative adverse consequences of hypovitaminosis D. Additionally to the recognized functions in the regulation of calcium absorption, bone remodeling, and bone growth, vitamin D plays a key role as a hormone, which is supported by various enzymatic, physiological, metabolic, and pathophysiological processes related to various human organs and systems. Accruing evidence supports that vitamin D plays a key role in pancreatic islet dysfunction and insulin resistance in type 2 diabetes. From an epidemiological viewpoint, numerous studies suggest that the growing incidence of type 2 diabetes in humans may be linked to the global trend of prevalent vitamin D insufficiency. In the past, this association has raised discussions due to the equivocal results, which lately have been more convincing of the true role of vitamin D supplementation in the prevention of incident type 2 diabetes. Most meta-analyses evaluating this role have been conducted in adults or young older persons (50-60 years old), with only one focusing on older populations, even if this is the population at greater risk of both hypovitaminosis D and type 2 diabetes. Therefore, we conducted an update of the previous systematic review and meta-analysis examining whether hypovitaminosis D (low serum 25OHD levels) can predict incident diabetes in prospective longitudinal studies among older adults. We found that low 25OHD was associated with incident diabetes in older adults even after adjusting for several relevant potential confounders, confirming and updating the results of the only previous meta-analysis conducted in 2017.

Persistence of vitamin D deficiency among Italian patients with acute myocardial infarction

BACKGROUND AND AIMS

Vitamin D deficiency is a common cardiovascular risk factor associated with the development of atherosclerosis. We evaluated changes in 25(OH)D concentrations in 1510 patients with acute myocardial infarction (AMI) over a long observation period, including the COVID-19 pandemic.

METHODS AND RESULTS

Patients were separated into four groups according to the year of enrolment, group 1 (2009-2010), group 2 (2014-2016), group 3 (2017-2019), and group 4 (2020-2022). The median 25(OH)D concentration in the overall cohort was 17.15 (10.3-24.7) ng/mL. The median plasma concentrations of 25(OH)D for groups 1, 2, 3, and 4 were 14.45 (7.73-22.58) ng/mL, 17.3 ng/mL (10.33-24.2), 18.95 (11.6-26.73) ng/mL and 19.05 (12.5-27.3) ng/mL, respectively. Although 25(OH)D levels increased over the years, the prevalence of vitamin D deficiency remained high in each group (68.4%, 61.4%, 53.8%, and 52% respectively). Hypovitaminosis D was predicted by the season influence (OR:2.03, p < 0.0001), higher body mass index (OR:1.25; p = 0.001), diabetes mellitus (OR:1.54; p = 0.001), smoking (OR:1.47; p = 0.001), older age (OR:1.07; p = 0.008), higher triglycerides levels (OR:1.02; p = 0.01), and female gender (OR:1.3; p = 0.038). After multivariable adjustment, vitamin D ≤ 20 ng/mL was an independent predictor of mortality.

CONCLUSION

Vitamin D deficiency is highly prevalent and persistent in patients with AMI despite a trend towards increasing 25(OH)D concentrations over the years. The frequent lockdowns did not reduce the levels of 25(OH)D in the fourth group. Low levels of 25(OH)D are an independent predictor of mortality.

The association between serum 25-hydroxyvitamin D levels and psoriasis in a large population-based cohort: a cross-sectional analysis of The Tromsø Study 2015-16

BACKGROUND

Case-control studies indicate an association between lower serum 25-hydroxyvitamin D [25(OH)D] levels and psoriasis. Data from larger population-based cohorts including mild cases are sparse.

OBJECTIVES

To investigate the association between 25(OH)D and psoriasis in a large population-based cohort, and assess possible effect modification by overweight.

METHODS

Data from the Tromsø Study 2015-16 (Tromsø7), which included 19 520 participants from the general population aged 40-79 years, were subjected to a cross-sectional analysis. We assessed the shapes of the relationships between 25(OH)D and psoriasis using fractional polynomials. Odds ratios (ORs) for lifetime and active psoriasis were estimated using logistic regression. Adjusted models included month of blood sampling, body mass index (BMI), age and sex. Two-way and additive interaction between BMI and 25(OH)D were explored.

RESULTS

From a total of 19 520 participants [10 203 women (52.3%); mean age 56.3 years (SD 10.4); mean 25[OH]D, 63.4 nmol L-1 (SD 21.9)], 2088 (10.7%) reported lifetime psoriasis and 1179 (6.0%) reported active psoriasis the past 12 months. There was no association between 25(OH)D and lifetime psoriasis [OR per 10 nmol L-1 increase in 25(OH)D 1.02, 95% confidence interval (CI) 0.99-1.04]. The relationship between 25(OH)D and active psoriasis was suggested to be nonlinear, but the model was not significant (P = 0.098). There was evidence for a superadditive effect (i.e. larger than the sum of the factors) of BMI > 27.5 kg m-2 and 25(OH)D < 25 nmol L-1 on the odds for active psoriasis (OR 1.92, 95% CI 1.18-3.12), but not for lifetime psoriasis (OR 1.41, 95% CI 0.93-2.15). There was no evidence for two-way interaction between BMI and 25(OH)D.

CONCLUSIONS

This large population-based study found no significant relationship between 25(OH)D and psoriasis. The analysis may have been underpowered to detect a threshold effect in the lower 25(OH)D spectrum. Interaction analysis indicates that high BMI and vitamin D deficiency combined increase the odds of active psoriasis more than the sum of these factors, with an estimated 92% higher odds for active psoriasis in participants with BMI > 27.5 kg m-2 and 25(OH)D < 25 nmol L-1. Providing advice to prevent vitamin D deficiency may be considered in the follow-up of overweight patients with psoriasis.

Vitamin D Status During Adolescence and the Impact of Lifestyle Changes: 2 Years' Follow-up From the Fit Futures Study

CONTEXT

Longitudinal data regarding vitamin D status in adolescence is scarce. This study presents population-based data from an Arctic adolescent population (n = 589) at 16 and 18 years.

OBJECTIVE

The aims of this study were to investigate changes in vitamin D status during 2 years in adolescence, and whether lifestyle changes were associated with serum 25-hydroxyvitamin D (s-25(OH)D) at follow-up.

METHODS

Fit Futures is a longitudinal study at 69°N in Norway. Participants had their s-25(OH)D levels analyzed in their first and third year of upper secondary school (median age 16 and 18 years), in Fit Futures 1 (FF1) and Fit Futures 2 (FF2), respectively. Self-reported lifestyle habits were registered through questionnaires. The association between lifestyle changes and s-25(OH)D levels at follow-up were calculated by regression analyses, controlling for baseline s-25(OH)D levels.

RESULTS

Longitudinal data were available for 309 girls and 280 boys. The proportion of adolescents with s-25(OH)D <50 nmol/L were 73.7% in FF1 and 77.1% in FF2, while the proportion <30 nmol/L constituted 35.7% in FF1 and 40.9% in FF2. Of those with s-25(OH)D <30 nmol/L (severe vitamin D deficiency) in FF1, 73.3% remained severely deficient in FF2. Among boys, an increase in UV exposure was significantly associated with higher s-25(OH)D levels in FF2 (beta; CI [nmol/L] 12.9; 9.1, 16.7). In girls, decreased vitamin/mineral supplement intake was significantly associated with lower s-25(OH)D at FF2 (-6.7; -10.2, -3.1), while increased UV (10.8; 7.0, 14.7) and combined hormonal contraceptive exposure (12.1; 6.0, 18.1) in FF2 was significantly associated with higher s-25(OH)D levels in FF2.

CONCLUSION

Severe vitamin D deficiency was prevalent throughout adolescence. Lifestyle changes may alter s-25(OH)D levels in this age group.

Relationship of serum 25-hydroxyvitamin D, obesity with new-onset obstructive sleep apnea

OBJECTIVE

The prospective association between vitamin D and obstructive sleep apnea (OSA) remains uncertain. We aimed to assess the association between serum 25-hydroxyvitamin D (25(OH)D), a major circulating form of vitamin D, and new-onset OSA, and examine the modifying effect of obesity.

MATERIALS AND METHODS

This prospective cohort study included 444,975 participants from UK Biobank without prior OSA. The primary outcome was new-onset OSA.

RESULTS

During a median follow-up duration of 12.0 years, 6051 (1.4%) participants occurred new-onset OSA. Overall, there was an inverse relation of serum 25(OH)D concentrations with the risk of new-onset OSA (per SD increment, HR, 0.92; 95%CI: 0.89-0.95). In the analysis of the interactions of serum 25(OH)D with the combination of BMI (<25, 25- < 30, and ≥30 kg/m2) and waist circumference (WC) (<90 and ≥90 cm) categories on new-onset OSA, the significantly inverse association of serum 25(OH)D and new-onset OSA was mainly found in participants with both BMI ≥ 25 kg/m2 and WC ≥ 90 cm (BMI 25-30 kg/m2 and WC ≥ 90 cm: per SD increment, HR, 0.90; 95%CI: 0.84-0.95; BMI ≥ 30 kg/m2 and WC ≥ 90 cm: per SD increment, HR, 0.85; 95%CI: 0.81-0.88), but not in other four groups with BMI < 25 kg/m2 or WC < 90 cm (P -interaction = 0.004).

CONCLUSIONS

There was an inverse relation of serum 25(OH)D with the risk of new-onset OSA in participants with both BMI ≥ 25 kg/m2 and WC ≥ 90 cm. Our findings suggest the importance of maintaining a higher serum 25(OH)D concentration for primary prevention of OSA in a population with obesity.

Long Follow-Up Times Weaken Observational Diet-Cancer Study Outcomes: Evidence from Studies of Meat and Cancer Risk

For years, prospective cohort studies of diet and cancer incidence have reported smaller effects than do retrospective case-control (CC) studies. The differences have been attributed to problems with CC studies, including dietary recall bias, poor matching of cases and controls, and confounding. The hypothesis evaluated here is that long follow-up periods between ascertainment of diet and cancer incidence weaken the findings. Prospective studies of cancer incidence with respect to serum 25-hydroxyvitamin D concentration have already shown reduced benefit of higher concentrations for longer follow-up periods. Evaluating that hypothesis for dietary factors involved searching the journal literature for meta-analyses of red meat and processed meat and cancer incidence. I used findings from observational studies for bladder, breast, colorectal, and gastric cancers. To evaluate the effect of duration of follow-up time, I used two approaches. First, I plotted the relative risks for CC studies for gastric cancer with respect to consumption of 100 g/day of red meat and for bladder cancer for 50 g/day of processed meat against the interval between the dietary data and cancer incidence. Second, I compared nested CC studies of meat and cancer incidence for five breast cancer studies and one colorectal cancer study. Both approaches yielded an inverse correlation between interval or follow-up time and relative risk. My findings strongly suggest that diet near time of cancer diagnosis is more important than for longer intervals, that results from meta-analyses should be revised when possible with appropriate adjustments for duration of follow-up, and that dietary guidelines be revised accordingly.

Serum 25-hydroxyvitamin D, type 2 diabetes, and liver-related outcomes: Secondary data analysis of a prospective recruited cohort

BACKGROUND

The association of vitamin D deficiency, which is prevalent in type 2 diabetes mellitus (T2DM), with liver disease and related mortality has not been quantified. Our study aimed to (1) investigate whether there is a synergistic association of vitamin D deficiency and T2DM with liver-related outcomes and (2) explore whether high 25-hydroxyvitamin D [25(OH)D] concentrations are associated with a lower risk of liver-related outcomes in T2DM.

METHOD

Leveraging the data from UK Biobank, we conducted 2 studies: study I assessed the joint associations of vitamin D deficiency [25(OH)D <50 nmol/L] and T2DM with liver-related outcomes among 439,276 participants, and study II explored the associations of vitamin D status with liver-related outcomes among 21,519 individuals with T2DM. Baseline T2DM was identified through medication, laboratory test, and electronic health-related records. Serum 25(OH)D was measured by direct competitive chemiluminescent immunoassay. Liver-related outcomes included 6 liver disease end points and mortality by overall liver disease, chronic liver disease, and severe liver disease.

RESULTS

During an average follow-up duration of 11.6 years, we observed a significant positive additive interaction effect (all synergy index>1.0) of T2DM and vitamin D deficiency on the risk of liver-related outcomes. Compared with participants without either T2DM or vitamin D deficiency, the multivariable-adjusted HRs of overall liver diseases were 1.29 for participants without T2DM but with vitamin D deficiency, 1.73 for participants with T2DM but without vitamin D deficiency, and 2.19 for participants with both T2DM and vitamin D deficiency. In individuals with T2DM, we observed that participants without vitamin D deficiency were inversely associated with incident liver disease and related mortality (multivariable-adjusted HRs 0.41-0.81) when compared with individuals with vitamin D deficiency.

CONCLUSIONS

There are positive synergistic associations of vitamin D deficiency and T2DM with liver-related outcomes. Inverse associations between serum 25(OH)D concentrations and liver-related outcomes were observed in individuals with T2DM.

Vitamin D deficiency and development of complications in individuals with type 1 and type 2 diabetes: A cohort study

AIMS

To investigate vitamin D deficiency as a risk marker for complications in individuals with type 1 and type 2 diabetes.

METHODS

A cohort study including 1448 adults with type 1 and 770 with type 2 diabetes. Individuals in the decile with lowest vitamin D level were classified as vitamin D deficient. Outcomes based on medical records and registers included mortality, major adverse cardiovascular event (MACE), heart failure, a composite kidney endpoint, albuminuria progression and sight-threatening eye disease. Risk in individuals with vitamin D deficiency was compared to the remaining using adjusted Cox proportional hazards models.

RESULTS

Vitamin D deficiency was associated with higher risk of MACE (adjusted hazard ratio (HR): 2.6; 95 % confidence interval (CI): 1.3-5.2) in type 1, but not in type 2 diabetes. Risk of heart failure was higher in individuals with vitamin D deficiency in both cohorts (HR (95%CI): 16 (4.8-50) in type 1 and 2.4 (1.1-5.5) in type 2 diabetes). Vitamin D deficiency was not associated with development of microvascular complications or mortality.

CONCLUSIONS

Vitamin D deficiency was a risk marker for MACE and heart failure in type 1 and for heart failure in type 2 diabetes, but not for microvascular complications or all-cause mortality.

25-hydroxyvitamin D concentrations and risk of incident dementia, mild cognitive impairment, and delirium in 443,427 UK Biobank participants

This study aimed to investigate the association between serum 25-hydroxyvitamin D (25(OH)D) levels and dementia, mild cognitive impairment (MCI), and delirium. Participants from the United Kingdom (UK) Biobank with complete information on serum 25(OH)D concentrations were enrolled. Dementia, MCI and delirium were defined using the UK Biobank algorithm. 443,427 participants with a mean (standard deviation) age of 56.8 (8.0) years were included in this study. Based on Cox regression models, serum 25(OH)D concentrations were inversely associated with the risk of dementia, MCI, and delirium in a dose-dependent manner after adjusting for demographics (P-trend <0.001). In comparison with 25(OH)D levels less than 32.4 nmol/L, participants with the highest 25(OH)D levels (i.e., >64.4 nmol/L) had the lowest risk of dementia (hazards ratio [HR]: 0.58, 95% confidence interval [CI] 0.49-0.69, P<0.001), MCI (HR: 0.55, 95% CI 0.37-0.84, P=0.005), and delirium (HR: 0.63, 95% CI 0.51-0.79, P<0.001). These results were consistent with the sensitivity analysis, in which participants with events occurring within the first two years of follow-up were excluded. This study found that a lower serum 25(OH)D concentration was significantly associated with a higher risk of dementia (including Alzheimer's disease and vascular dementia), MCI, and delirium.

Vitamin D status and chronic obstructive pulmonary disease risk: a prospective UK Biobank study

BACKGROUND

Low vitamin D status has been linked to an increased risk for various inflammatory diseases. Conflicting results have been reported regarding chronic obstructive pulmonary disease (COPD). This study aims to investigate the associations of serum 25-hydroxyvitamin D (25(OH)D) concentrations with COPD risk and survival.

METHODS

We included 403 648 participants with serum 25(OH)D measurements and free of COPD at baseline from UK Biobank. Follow-up was until 30 September 2021. Multivariable-adjusted cox regression models were applied to estimate HRs and 95% CIs for the associations of season-standardised 25(OH)D concentrations with COPD risk and survival. The restricted cubic splines were used to assess dose-response relationship. Kaplan-Meier estimation was used to create graphs of the survival curves.

RESULTS

During a median follow-up of 12.3 (IQR: 11.4-13.2) years, 11 008 cases of COPD were recorded. We observed a non-linear inverse association between 25(OH)D concentrations and COPD risk. Compared with participants in the fourth quintile of 25(OH)D, those in the lowest quintile were associated with a 23% higher risk (HR, 1.23; 95% CI, 1.16 to 1.31). Stronger associations were observed for the risk in men and current smokers (Both p for interaction <0.05). In survival analyses, compared with the fourth quintile, cases in the lowest quintile had a 38% higher risk for overall death (HR, 1.38; 95% CI, 1.22 to 1.56).

CONCLUSION

Our findings indicate that serum 25(OH)D concentrations are non-linearly negatively associated with incidence and mortality of COPD, suggesting a potential protective role of vitamin D in the pathogenesis of COPD.

Vitamin D Status in Women with a History of Infertility and Decreased Fecundability: A Population-Based Study

BACKGROUND

Infertility and fecundability problems have been linked with lower 25-hydroxyvitamin D (25(OH)D) concentrations, but studies conducted with small, heterogenous or selected populations have shown inconsistent results.

METHODS

This study included women at age 31 from prospective population-based Northern Finland Birth Cohort 1966. Serum 25(OH)D concentrations were evaluated between women with or without previous infertility examinations or treatments (infertility group, n = 375, reference group, n = 2051) and time to pregnancy (TTP) of over 12 months (decreased fecundability group, n = 338) with a wide range of confounders. Furthermore, 25(OH)D concentrations were also compared among reproductive outcomes.

RESULTS

The mean 25(OH)D concentration was lower and 25(OH)D < 30 nmol/L was more frequent in women with a history of infertility compared to reference group. Moreover, 25(OH)D > 75 nmol/L was more frequent in the reference group. The mean 25(OH)D concentration was lower in women who had had multiple miscarriages. Both history of infertility (β = -2.7, 95% confidence interval (CI) -4.6, -0.7) and decreased fecundability associated with lower 25(OH)D concentration (β = -4.1, 95% CI -7.4, -0.8) after adjustments. In conclusion, this population-based study demonstrated that previous infertility and decreased fecundability were associated with lower 25(OH)D.

Pathology-supported genetic testing for the application of breast cancer pharmacodiagnostics: family counselling, lifestyle adjustments and change of medication

BACKGROUND

Pathology-supported genetic testing (PSGT) enables transitioning of risk stratification from the study population to the individual.

RESEARCH DESIGN AND METHODS

We provide an overview of the translational research performed in postmenopausal breast cancer patients at increased risk of osteoporosis due to aromatase inhibitor therapy, as the indication for referral. Both tumour histopathology and blood biochemistry levels were assessed to identify actionable disease pathways using whole exome sequencing (WES).

RESULTS

The causes and consequences of inadequate vitamin D levels as a modifiable risk factor for bone loss were highlighted in 116 patients with hormone receptor-positive breast cancer. Comparison of lifestyle factors and WES data between cases with vitamin D levels at extreme upper and lower ranges identified obesity as a major discriminating factor, with the lowest levels recorded during winter. Functional polymorphisms in the vitamin D receptor gene contributed independently to therapy-related osteoporosis risk. In a patient with invasive lobular carcinoma, genetic counselling facilitated investigation of the potential modifying effect of a rare CDH1 variant co-occurring withBRCA1 c.66dup (p.Glu23ArgfsTer18).

CONCLUSION

Validation of PSGT as a three-pronged pharmacodiagnostics tool for generation of adaptive reports and data reinterpretation during follow-up represents a new paradigm in personalised medicine, exposing significant limitations to overcome.

The gut microbiota-bile acid axis mediates the beneficial associations between plasma vitamin D and metabolic syndrome in Chinese adults: A prospective study

BACKGROUND & AIMS

Previous studies have suggested that circulating 25-hydroxyvitamin D (25 [OH]D, VD) and the gut microbiota-bile acid axis play crucial roles in metabolic health. Exploring the mediating role of the gut microbiota-bile acid axis would improve our understanding of the mechanisms underlying the effects of VD on human metabolic health. This study examined the association between plasma 25(OH)D and the prevalence/incidence of metabolic syndrome (MetS) and the mediating role of the gut microbiota-bile acid axis.

METHODS

This prospective study included 3180 participants with plasma 25(OH)D data at baseline and 2966 participants with a 9-year follow-up. MetS was determined every three years. The gut microbiota was analyzed by 16S rRNA sequencing in 1752 participants, and targeted bile acid metabolites in feces were further determined in 974 participants using UPLC‒MS/MS at the middle of the study. Mediating roles of microbiota and bile acids in the VD-MetS associations were analyzed using mediation/path analyses adjusted for potential confounders.

RESULTS

Among the 2966 participants who were followed-up, 1520, 193, 647, and 606 were MetS-free (normal), recovered, had incident MetS, and had persistent MetS, respectively. The multivariable-adjusted ORs (95% CIs) of MetS prevalence were 0.65 (0.50, 0.84) for baseline MetS and 0.46 (0.33, 0.65) for 9-year persistent MetS in quartile 4 (compared to quartile 1) of plasma 25(OH)D (median: 37.7 vs. 19.6, ng/ml). The corresponding HR (95% CI) of 9-year MetS incidence was 0.71 (0.56, 0.90) (all P-trend < 0.05). Higher VD concentrations were associated with greater α-diversity of the gut microbiota, which was inversely correlated with MetS risk. The groups classified by VD and MetS status had significantly different β-diversity. Ruminiclostridium-6 and Christensenellaceae R-7 group were enriched in the high-VD group and were inversely associated with MetS. However, opposite associations were observed for Lachnoclostridium and Acidaminococcus. The overlapping differential microbial score (ODMS) developed from the four differential genera explained 12.2% of the VD-MetS associations (P_mediation = 0.015). Furthermore, the fecal bile acid score created from 11 differential bile acids related to ODMS and MetS mediated 34.2% of the association between ODMS and MetS (P_mediation = 0.029). Path analyses showed that the inverse association between plasma 25(OH)D and MetS could be mediated by the gut microbiota-bile acid axis.

CONCLUSIONS

The findings suggest that the gut microbiota-bile acid axis partially mediates the beneficial association between plasma 25(OH)D and the risk of persistent MetS and incident MetS in the Chinese population.

Vitamin D Status in Diabetic Moroccan Children And Adolescents: a Case-control Study

Background: Type 1 diabetes mellitus (T1DM) incidence is currently increasing worldwide, and different environmental players along with genetic predisposition, could be involved as powerful triggers of this disease onset. In this study, we aim to shed the light on the relationship between 25OHD deficiency and T1DM. Patients and methods: A case-control study was laid out to compare serum 25OHD level between T1DM patients and controls. A total of 147 T1DM patients aged under 19 years old were recruited from our Endocrinology-Diabetology and Nutrition department between October 2014 and December 2019. A total of 147 controls were randomly enlisted from clinical biochemistry laboratory of our center, and were carefully matched. The levels of 25OHD in the serum were determined in T1DM patients and nondiabetic controls. Results: Average serum 25OHD concentration was established in both groups; reaching 19,29 ±6,13 ng/ml in the control arm and 15,02 ± 6,48 ng/ml in the selected group with T1DM independently of the disease duration. However, the mean serum 25OHD concentration was not significantly different between the two T1DM subgroups according to diabetes duration below or above 5 years, and 25OHD concentration remained lower either in winter or summer months. A negative correlation was noticed between HbA1c and serum 25 OHD concentration in T1DM patients and was statistically significant (p<0,05). Conclusion: Key messages on the importance of vitamin D status, particularly in diabetic children and adolescents, should be spread widely in order to start a suitable vitamin supplementation, and establish guidelines regarding its timing at adequate recommended doses..

Is the vitamin D status of patients with COVID-19 associated with reduced mortality? A systematic review and meta-analysis

To conduct a systematic review and meta-analysis of studies assessing the association between serum vitamin D status and mortality in patients with COVID- 19. We searched PubMed and Embase for studies addressing the association of serum vitamin D levels and COVID-19 mortality published until April 24, 2022. Risk ratios (RRs) and 95% confidence interval (CIs) were pooled using fixed or random effects models. The risk of bias was assessed using the Newcastle-Ottawa Scale. The meta-analysis included 21 studies that measured serum vitamin D levels close to the date of admission, of which 2 were case-control and 19 were cohort studies. Vitamin D deficiency was associated with COVID-19 mortality in the overall analysis but not when the analysis was adjusted to vitamin D cutoff levels < 10 or < 12 ng/mL (RR 1.60, 95% CI 0.93-2.27, I2 60.2%). Similarly, analyses including only studies that adjusted measures of effect for confounders showed no association between vitamin D status and death. However, when the analysis included studies without adjustments for confounding factors, the RR was 1.51 (95% CI 1.28-1.74, I2 0.0%), suggesting that confounders may have led to many observational studies incorrectly estimating the association between vitamin D status and mortality in patients with COVID-19. Deficient vitamin D levels were not associated with increased mortality rate in patients with COVID-19 when the analysis included studies with adjustments for confounders. Randomized clinical trials are needed to assess this association.

Associations between Serum 25-hydroxyvitamin D, Sun Exposure Time, Dietary Vitamin D Intake, and New-Onset Acute Kidney Injury among 413,169 UK Adults

BACKGROUND

The prospective associations of serum 25(OH)D, sun exposure time, and dietary vitamin D with risk of acute kidney injury (AKI) are unclear.

OBJECTIVES

We aimed to evaluate the relations of serum 25(OH)D, sun exposure time, and dietary vitamin D intake with new-onset AKI and examine whether genetic susceptibility modified such associations.

METHODS

A total of 413,169 participants (mean age was 56.4 y, 47.2% were male) from UK Biobank without prior AKI were included. Sun exposure time was expressed as time spent outdoors. Genetic risk scores were calculated by 263 single nucleotide polymorphisms, which showed significant associations with the estimated glomerular filtration rate. The primary outcome was new-onset AKI. Cox proportional hazards models were used to estimate the HRs and (95% CIs).

RESULTS

During a median follow-up duration of 12 y, 16,938 (4.1%) participates developed new-onset AKI. Compared with those with serum 25(OH)D <25 nmol/L, significantly lower risks of new-onset AKI were found between participants with 25(OH)D 25 to <50 nmol/L (adjusted HR: 0.76; 95% CI: 0.73, 0.80), and ≥50 nmol/L (adjusted HR: 0.69; 95% CI: 0.65, 0.72). Moreover, in summer, participants who spent ≥4 h outdoors per day (tertile 3) had a significantly lower risk of new-onset AKI (adjusted HR: 0.90; 95% CI: 0.86, 0.95) than those who spent <2 h outdoors per day (tertile 1). Similar results were found for time spent outdoors in winter. In addition, those in quintile 5 of dietary vitamin D intake showed a lower risk of new-onset AKI (≥4.2 μg/d, adjusted HR: 0.90; 95% CI: 0.82, 0.98) than those in quintile 1 (<1.0 μg/d). Genetic risks of kidney diseases did not significantly modify all the 3 above associations (all P-interactions >0.05).

CONCLUSIONS

Serum 25(OH)D concentrations, time spent outdoors, and dietary vitamin D intake were all inversely associated with new-onset AKI, independent of genetic risks for kidney diseases.

Adiposity and physical activity are among the main determinants of serum vitamin D concentrations in older adults: the EpiFloripa Aging Cohort Study

The identification of factors associated with 25-hydroxycholecalciferol (25(OH)D) concentration can help suggest more specific interventions for older adults. In this cross-sectional study of older adults from southern Brazil, we hypothesized that some sociodemographic, behavioral, and health factors positively or negatively influence the 25(OH)D concentration in this population. This analysis was performed using data from the second wave of the EpiFloripa Aging Cohort Study (2013-2015). Serum 25(OH)D levels were classified according to the guidelines of the Endocrine Society. Multinomial logistic regression was performed to evaluate the relative risks of sociodemographic, behavioral, and health factors in each 25(OH)D category. A total of 574 older adults (aged 63-93 years) participated in this study. The prevalence of insufficiency (21-29 ng/mL) was 43.7% and that of deficiency (≤20 ng/mL) was 23.5%. In the adjusted analysis, female sex, higher levels of low-density lipoprotein cholesterol (LDL-C ≥160 mg/dL), obesity by adiposity (body fat percentage [%fat], male ≥31%; female ≥43%), and body mass index (BMI, >30 kg/m²) presented higher relative risks for insufficiency than for sufficiency. For those with deficiency, the associated factors were female sex, disability in 4 or more activities of daily living (ADLs), LDL-C ≥100 mg/dL, and obesity by %fat and BMI. A protective factor against insufficiency and deficiency was active leisure-time physical activity (PA, ≥150 min/week). Our results demonstrated that being female and having modifiable factors, such as high levels of LDL-C, obesity, and disability on ADLs, were negatively associated with hypovitaminosis D. On the other hand, leisure-time PA was positively associated with adequate serum vitamin D concentration.

Vitamin D Status Over Time and Cognitive Function in Norwegian Older Adults: A Prospective Cohort of the HUNT Study

BACKGROUND

There is conflicting evidence regarding the association between vitamin D status and cognitive function in population studies. The use of one-time vitamin D measurement in cognitive health studies may not reflect long-term vitamin D status in the body.

OBJECTIVE

We aimed to examine the relationship of vitamin D status measured over time with the risk of neurocognitive disorders (NCDs) in Norwegian older adults.

DESIGN

Prospective cohort study.

SETTING

Regional, Trøndelag Health Study.

PARTICIPANTS

This study followed a random cohort of 717 participants from HUNT2 (1995-97) and HUNT3 (2006-08) to HUNT4 70+ (2017-19). The mean age at HUNT4 70+ was 77.7 years.

METHODS

Seasonal-standardized serum 25-hydroxyvitamin D [25(OH)D] levels in HUNT2 and HUNT3 were averaged and used as either a categorical variable (<50 and ≥50 nmol/L) or a continuous variable (per 25 nmol/L decrease). In the cohort aged 70 years or over (HUNT4 70+), NCDs consisting of mild cognitive impairment (MCI) and dementia were diagnosed by clinical experts according to the DSM-5 criteria. Logistic and linear regression models were used to estimate odds ratios (ORs) and regression coefficients (beta) with 95% confidence intervals (CIs) to assess the relationship between 25(OH)D levels and the risk of NCDs or the Montreal Cognitive Assessment (MoCA) score.

RESULTS

In total, 347 (48.4%) had NCDs in HUNT4, with 33.3% having MCI and 15.1% having dementia. Compared with participants with serum 25(OH)D ≥50 nmol/L, those with 25(OH)D <50 nmol/L had a similar risk of NCDs (OR 1.05, 95% CI 0.76 to 1.46). No association was observed with the risk of MCI (OR 1.01, 95% CI 0.71 to 1.44) or dementia (OR 1.16, 95% CI 0.70 to 1.92), respectively. In a subsample of participants evaluated with the MoCA (n=662), a 25 nmol/L decrease in serum 25(OH)D was not associated with a change in MoCA score (beta 0.33, 95% CI -0.17 to 0.85).

CONCLUSION

Vitamin D insufficiency defined by two times measurements of serum 25(OH)D with a 10-year interval was not associated with the risk of NCDs in a cohort of older Norwegian adults. Future studies utilizing multiple vitamin D measurements with a longer follow-up duration and larger sample size are warranted.

Circulating vitamin D and breast cancer risk: an international pooling project of 17 cohorts

Laboratory and animal research support a protective role for vitamin D in breast carcinogenesis, but epidemiologic studies have been inconclusive. To examine comprehensively the relationship of circulating 25-hydroxyvitamin D [25(OH)D] to subsequent breast cancer incidence, we harmonized and pooled participant-level data from 10 U.S. and 7 European prospective cohorts. Included were 10,484 invasive breast cancer cases and 12,953 matched controls. Median age (interdecile range) was 57 (42-68) years at blood collection and 63 (49-75) years at breast cancer diagnosis. Prediagnostic circulating 25(OH)D was either newly measured using a widely accepted immunoassay and laboratory or, if previously measured by the cohort, calibrated to this assay to permit using a common metric. Study-specific relative risks (RRs) for season-standardized 25(OH)D concentrations were estimated by conditional logistic regression and combined by random-effects models. Circulating 25(OH)D increased from a median of 22.6 nmol/L in consortium-wide decile 1 to 93.2 nmol/L in decile 10. Breast cancer risk in each decile was not statistically significantly different from risk in decile 5 in models adjusted for breast cancer risk factors, and no trend was apparent (P-trend = 0.64). Compared to women with sufficient 25(OH)D based on Institute of Medicine guidelines (50- < 62.5 nmol/L), RRs were not statistically significantly different at either low concentrations (< 20 nmol/L, 3% of controls) or high concentrations (100- < 125 nmol/L, 3% of controls; ≥ 125 nmol/L, 0.7% of controls). RR per 25 nmol/L increase in 25(OH)D was 0.99 [95% confidence intervaI (CI) 0.95-1.03]. Associations remained null across subgroups, including those defined by body mass index, physical activity, latitude, and season of blood collection. Although none of the associations by tumor characteristics reached statistical significance, suggestive inverse associations were seen for distant and triple negative tumors. Circulating 25(OH)D, comparably measured in 17 international cohorts and season-standardized, was not related to subsequent incidence of invasive breast cancer over a broad range in vitamin D status.

Longitudinal Stability of Vitamin D Status and Its Association With Bone Mineral Density in Middle-aged Australians

Context

The skeletal effects of vitamin D remain controversial and it is uncertain whether variation in serum 25-hydroxyvitamin D (25OHD) levels over time influences bone mineral density (BMD).

Objective

We evaluated longitudinal stability of serum 25OHD and associations with changes in BMD in participants aged 46-70 years at baseline.

Methods

We studied 3698 Busselton Healthy Ageing Study participants (2040 female) with serum 25OHD and dual-energy x-ray absorptiometry (DXA) BMD assessments at baseline and at ∼6 years follow-up. Restricted cubic splines were used to evaluate associations between changes in 25OHD and BMD.

Results

Mean season-corrected serum 25OHD was 81.3 ± 22.7 and 78.8 ± 23.1 nmol/L at baseline and 6 years, respectively, and showed moderate correlation (intraclass correlation coefficient: 0.724). Significant predictors of change in 25OHD concentration (Δ25OHD) included baseline 25OHD, change in body mass index and vitamin D supplementation at follow-up. Greater decline in serum 25OHD over time was associated with significantly greater reduction in BMD at total hip and femoral neck, but the magnitude of the differences was small (estimated differences 0.004 g/cm² and 0.005-0.007 g/cm², respectively, for lowest quartile of Δ25OHD compared with higher quartiles, adjusted for sex, baseline BMD, 25OHD, and demographics). No significant associations between Δ25OHD and lumbar spine BMD were observed. Increase in 25OHD levels was not associated with change in BMD.

Conclusions

In this predominantly vitamin D-replete middle-aged cohort, serum 25OHD showed moderate longitudinal stability. Declining serum 25OHD over time was associated with greater reduction in BMD at the total hip and femoral neck.

Relationships of Serum 25-Hydroxyvitamin D Concentrations, Diabetes, Genetic Susceptibility, and New-Onset Chronic Kidney Disease

OBJECTIVE

The prospective relation of vitamin D status with the risk of chronic kidney diseases (CKD) remains uncertain. We aimed to examine the association of serum 25-hydroxyvitamin D (25OHD) with new-onset CKD in participants with and without diabetes at baseline and examine the potential modifications by genetic susceptibility on the association.

RESEARCH DESIGN AND METHODS

Included were 348,243 adults from the UK Biobank without prior CKD at baseline. Serum 25OHD concentrations were measured by chemiluminescent immunoassay method. Genetic risk score of CKD was calculated by 263 single nucleotide polymorphisms, which showed significant associations with estimated glomerular filtration rate. The primary outcome was new-onset CKD.

RESULTS

During a median follow-up duration of 12.1 years, 9,344 new-onset CKD were documented. Overall, there was a significant inverse association between baseline serum 25OHD and new-onset CKD in participants with diabetes (per SD increment, adjusted hazard ratio [HR] 0.91; 95% CI 0.86-0.96), but not in those without diabetes (per SD increment, adjusted HR 0.98; 95% CI 0.96-1.01; P-interaction between serum 25OHD and diabetes = 0.004). Accordingly, among participants with diabetes, compared with those baseline serum 25OHD <25 nmol/L, a significantly lower risk of new-onset CKD was found in those with 25OHD ≥50 nmol/L (adjusted HR 0.77; 95% CI 0.67-0.89). Moreover, the genetic risk of CKD did not significantly modify the association between baseline serum 25OHD and new-onset CKD among participants with diabetes (P-interaction = 0.127).

CONCLUSIONS

There was an inverse association between baseline serum 25OHD and new-onset CKD in participants with diabetes. The inverse association was not found in participants without diabetes.

Nonlinear Association between Serum 25-Hydroxyvitamin D and All-Cause Mortality in Adults with Inflammatory Bowel Disease in a Prospective Cohort Study

BACKGROUND

Nonlinear association between serum 25-hydroxyvitamin D [25(OH)D] concentration and all-cause mortality has been widely reported for the general population, but this association has not been quantified for individuals with inflammatory bowel disease (IBD).

OBJECTIVES

The aim was to explore the association between serum 25(OH)D and all-cause mortality in individuals with IBD.

METHODS

We identified 2690 females and 2532 males aged 40-69 y with diagnosed IBD at baseline in the UK Biobank. Serum 25(OH)D concentration was measured by direct competitive chemiluminescent immunoassay. The outcome was all-cause mortality, ascertained via the death registry. Cox proportional hazard regression was used to evaluate associations between serum 25(OH)D in quintiles and all-cause mortality among individuals with IBD [Crohn disease (CD; n = 1760) and ulcerative colitis (UC; n = 3462)]. Restricted cubic splines were used to investigate potential nonlinearity.

RESULTS

During the mean follow-up period of 11.9 y, 529 deaths (198 in CD and 331 in UC) were documented among 5222 individuals with IBD. Compared with the lowest quintile of serum 25(OH)D, HRs for the second to the highest quintiles were 0.82 (95% CI: 0.63, 1.06), 0.63 (95% CI: 0.47, 0.83), 0.64 (95% CI: 0.48, 0.85), and 0.74 (95% CI: 0.55, 0.99), respectively. Nonlinearity was detected in the dose-response association between serum 25(OH)D concentration and all-cause mortality (P-nonlinearity < 0.001), and 25(OH)D concentrations of 44-78 nmol/L were associated with a 50% lower risk of all-cause mortality (than 10 nmol/L). Subgroup analyses showed that the nonlinear association mostly applied to females (P-nonlinearity < 0.001 compared with 0.080 in males).

CONCLUSIONS

We observed a nonlinear association, mostly applicable to females, between serum 25(OH)D concentrations and all-cause mortality among individuals with IBD. A 25(OH)D concentration range of 44-78 nmol/L can serve as a starting point for future research to confirm recommended 25(OH)D concentrations for individuals with IBD.

Maternal Passive Smoking, Vitamin D Deficiency and Risk of Spontaneous Abortion

Background: Maternal passive smoking and vitamin D deficiency might elevate risk of spontaneous abortion. The study aimed to investigate the association of co-exposure to passive smoking and vitamin D deficiency with the risk of spontaneous abortion. Methods: A population-based case-control study was performed among non-smoking women in Henan Province, China, with 293 spontaneous abortion cases and 496 liveborn controls with term, normal birthweight. Results: Compared to women without exposure to passive smoking nor vitamin D deficiency, women with deficient vitamin D alone and women with exposure to passive smoking alone had increased risk of spontaneous abortion (OR = 1.76, 95%CI: 1.08~2.89; OR = 1.73, 95%CI: 1.11~2.69, respectively). The risk of spontaneous abortion was even higher for those with co-exposure to passive smoking and vitamin D deficiency (OR = 2.50, 95%CI: 1.63~3.84). A dose-response relationship was found of an incremental risk of spontaneous abortion with rising numbers of exposures to passive smoking and vitamin D deficiency (p < 0.001). Conclusion: Co-exposure to passive smoking and vitamin D deficiency was associated with an elevated risk of spontaneous abortion, and the risk of spontaneous abortion rose with rising numbers of exposures. Intervention programs need to specifically target the vulnerable groups of pregnant women with both malnutrition and unfavorable environmental exposure.

Vitamin D status is heritable and under environment-dependent selection in the wild

Vitamin D has a well-established role in skeletal health and is increasingly linked to chronic disease and mortality in humans and companion animals. Despite the clear significance of vitamin D for health and obvious implications for fitness under natural conditions, no longitudinal study has tested whether the circulating concentration of vitamin D is under natural selection in the wild. Here, we show that concentrations of dietary-derived vitamin D2 and endogenously produced vitamin D3  metabolites are heritable and largely polygenic in a wild population of Soay sheep (Ovis aries). Vitamin D2  status was positively associated with female adult survival, and vitamin D3  status predicted female fecundity in particular, good environment years when sheep density and competition for resources was low. Our study provides evidence that vitamin D status has the potential to respond to selection, and also provides new insights into how vitamin D metabolism is associated with fitness in the wild.

Vitamin D, oral health, and disease characteristics in juvenile idiopathic arthritis: a multicenter cross-sectional study

Background

Vitamin D deficiency has been associated with autoimmune diseases and oral health. Knowledge about the association between vitamin D status and oral conditions in JIA is limited. We aimed to investigate vitamin D status in a cohort of Norwegian children and adolescents with JIA and possible associations between serum vitamin D levels, clinical indicators of oral health, and JIA disease characteristics.

Methods

This multi-center, cross-sectional study, included individuals with JIA aged 4–16 years from three geographically spread regions in Norway. Demographic data, age at disease onset, disease duration, JIA category, disease status, medication, and vitamin D intake were registered. One blood sample per individual was analyzed for 25(OH) vitamin D, and the level of insufficiency was defined as < 50 nmol/L. A clinical oral examination was performed applying commonly used indices in epidemiological studies of dental caries, dental erosion, enamel defects, gingival bleeding, and oral hygiene. Serum vitamin D was used as exposure variable in multivariable regression analyses to estimate the associations between insufficient vitamin D level, JIA disease status, and oral conditions, with adjustments for age, sex, geographical region, BMI, seasonal blood sampling, and parental education.

Results

Among the 223 participants with JIA, 97.3% were Caucasians, 59.2% were girls, and median age was 12.6 years. Median disease duration was 4.6 years, and 44.4% had oligoarticular JIA. Mean serum vitamin D level was 61.4 nmol/L and 29.6% had insufficient levels. Vitamin D levels did not differ between sexes, but between regions, iso-BMI categories, age groups, and seasons for blood sampling. Insufficient vitamin D levels were associated with dentin caries (adjusted OR 2.89, 95% CI 1.43–5.86) and gingival bleeding (adjusted OR 2.36, 95% CI 1.10–5.01). No associations were found with active JIA disease or more severe disease characteristics.

Conclusion

In our study, nearly 30% had vitamin D insufficiency, with a particularly high prevalence among adolescents. Vitamin D insufficiency was associated with dentin caries and gingival bleeding, but not with JIA disease activity. These results point to the need for a multidisciplinary approach in the follow-up of children with JIA, including an increased focus on vitamin D status and oral health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02349-1.

Prospective associations between vitamin D and depression in middle-aged adults: findings from the UK Biobank cohort

BACKGROUND

A possible role of vitamin D in the pathophysiology of depression is currently speculative, with more rigorous research needed to assess this association in large adult populations. The current study assesses prospective associations between vitamin D status and depression in middle-aged adults enrolled in the UK Biobank.

METHODS

We assessed prospective associations between vitamin D status at the baseline assessment (2006-2010) and depression measured at the follow-up assessment (2016) in 139 128 adults registered with the UK Biobank.

RESULTS

Amongst participants with no depression at baseline (n = 127 244), logistic regression revealed that those with vitamin D insufficiency [adjusted odds ratio (aOR) = 1.14, 95% confidence interval (CI) = 1.07-1.22] and those with vitamin D deficiency (aOR = 1.24, 95% CI 1.13-1.36) were more likely to develop new-onset depression at follow-up compared with those with optimal vitamin D levels after adjustment for a wide range of relevant covariates. Similar prospective associations were reported for those with depression at baseline (n = 11 884) (insufficiency: aOR = 1.11, 95% CI 1.00-1.23; deficiency: aOR = 1.30, 95% CI 1.13-1.50).

CONCLUSIONS

The prospective associations found between vitamin D status and depression suggest that both vitamin D deficiency and insufficiency might be risk factors for the development of new-onset depression in middle-aged adults. Moreover, vitamin D deficiency (and to a lesser extent insufficiency) might be a predictor of sustained depressive symptoms in those who are already depressed. Vitamin D deficiency and insufficiency is very common, meaning that these findings have significant implications for public health.

Vitamin D supplementation and postoperative atrial fibrillation

Vitamin D is an important vitamin that has hormone-like effects in the human body. 1,25-dihydroxy vitamin D (1,25(OH)2 D) is known as the active form of vitamin D. Activated vitamin D can affect cellular proliferation, apoptosis, cellular membrane transport, immune system, and aging through genes. Postoperative atrial fibrillation (PoAF) is an important problem that increases mortality and morbidity rates after cardiac surgery operations. Various studies have been conducted on the relationship between vitamin D and PoAF. Although there are studies in the literature showing that vitamin D supplementation reduces cardiovascular mortality and morbidity in different study types (randomized vs. observational), there are also studies showing that it has no effect on clinical outcomes. Since the subject is atrial fibrillation, the conditions of the study groups such as age, the prevalence of coronary artery disease, degree of hypertension, and lung disease should be analyzed well. On the other hand, vitamin D supplementation should be carefully determined for which patient, for how long, and at what dose.

Prediagnostic Serum Vitamin D, Vitamin D Binding Protein Isoforms, and Cancer Survival

BACKGROUND

Higher circulating vitamin D has been associated with improved overall cancer survival, but data for organ-specific cancers are mixed.

METHODS

We examined the association between prediagnostic serum 25-hydroxyvitamin D [25(OH)D], the recognized biomarker of vitamin D status, and cancer survival in 4038 men and women diagnosed with 1 of 11 malignancies during 22 years of follow-up (median = 15.6 years) within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Multivariable-adjusted proportional hazards regression estimated hazard ratios (HR) and 95% confidence intervals (CI) for associations between baseline 25(OH)D concentration and subsequent cancer survival; we also stratified on the common vitamin D binding protein isoforms (Gc1f, Gc1s, and Gc2) defined by two single-nucleotide polymorphisms (rs7041 and rs4588) in the vitamin D binding protein gene GC. All P values were 2-sided.

RESULTS

Higher 25(OH)D concentrations were associated with greater overall cancer survival (HR for cancer mortality = 0.83, 95% CI = 0.70 to 0.98 for highest vs lowest quintile; Ptrend = .05) and lung cancer survival (HR = 0.63, 95% CI = 0.44 to 0.90; Ptrend = .03). These associations were limited to cases expressing the Gc2 isoform (HR = 0.38 for Gc2-2, 95% CI = 0.14 to 1.05 for highest vs lowest quintile; Ptrend = .02; and HR = 0.30 for Gc1-2/Gc2-2 combined, 95% CI = 0.16 to 0.56; Ptrend < .001 for overall and lung cancer, respectively).

CONCLUSIONS

Higher circulating 25(OH)D was associated with improved overall and lung cancer survival. As this was especially evident among cases with the genetically determined Gc2 isoform of vitamin D binding protein, such individuals may gain a cancer survival advantage by maintaining higher 25(OH)D blood concentrations.

Association of serum 25-hydroxyvitamin D concentrations with risk of dementia among individuals with type 2 diabetes: A cohort study in the UK Biobank

BACKGROUND

Several epidemiological studies have suggested that vitamin D status is associated with risk of dementia in general populations. However, due to the synergistic effect between diabetic pathology and neuroinflammation, and the prothrombotic profile in patients with diabetes, whether vitamin D is associated with risk of dementia among patients with diabetes is unclear. This study aimed to investigate the associations of circulating vitamin D levels with risks of all-cause dementia, Alzheimer disease (AD), and vascular dementia (VD) among adults with type 2 diabetes (T2D).

METHODS AND FINDINGS

This study included 13,486 individuals (≥60 years) with T2D and free of dementia at recruitment (2006-2010) from the UK Biobank study. Serum 25-hydroxyvitamin D (25[OH]D) concentrations were measured using the chemiluminescent immunoassay method at recruitment. Serum 25(OH)D ≥ 75 nmol/L was considered sufficient, according to the Endocrine Society Clinical Practice Guidelines. Incidence of all-cause dementia, AD, and VD cases was ascertained using electronic health records (EHRs). Each participant's person-years at risk were calculated from the date of recruitment to the date that dementia was reported, date of death, date of loss to follow-up, or 28 February 2018, whichever occurred first. Among the 13,486 individuals with T2D (mean age, 64.6 years; men, 64.3%), 38.3% had vitamin D ≥ 50 nmol/L and only 9.1% had vitamin D ≥ 75 nmol/L. During a mean follow-up of 8.5 years, we observed 283 cases of all-cause dementia, including 101 AD and 97 VD cases. Restricted cubic spline analysis demonstrated a nonlinear relationship between serum 25(OH)D and risk of all-cause dementia (Pnonlinearity < 0.001) and VD (Pnonlinearity = 0.007), and the nonlinear association reached borderline significance for AD (Pnonlinearity = 0.06), with a threshold at around a serum 25(OH)D value of 50 nmol/L for all the outcomes. Higher serum levels of 25(OH)D were significantly associated with a lower risk of all-cause dementia, AD, and VD. The multivariate hazard ratios and 95% confidence intervals for participants who had serum 25(OH)D ≥ 50 nmol/L, compared with those who were severely deficient (25[OH]D < 25 nmol/L), were 0.41 (0.29-0.60) for all-cause dementia (Ptrend < 0.001), 0.50 (0.27-0.92) for AD (Ptrend = 0.06), and 0.41 (0.22-0.77) for VD (Ptrend = 0.01). The main limitation of the current analysis was the potential underreporting of dementia cases, as the cases were identified via EHRs.

CONCLUSIONS

In this study, we observed that higher concentrations of serum 25(OH)D were significantly associated with a lower risk of all-cause dementia, AD, and VD among individuals with T2D. Our findings, if confirmed by replication, may have relevance for dementia prevention strategies that target improving or maintaining serum vitamin D concentrations among patients with T2D.

Associations of 25 Hydroxyvitamin D and High Sensitivity C-reactive Protein Levels in Early Life

Vitamin D deficiency and elevated high sensitivity C-reactive protein (hs-CRP) have been associated with several health outcomes, but knowledge on early life trajectories and association between 25 hydroxyvitamin D (25(OH)D) and hs-CRP is lacking. We investigated the association between longitudinal measurements of 25(OH)D and hs-CRP, respectively, from pregnancy to childhood and throughout childhood in two Danish mother–child cohorts—the COPSAC₂₀₁₀ and COPSAC₂₀₀₀. In COPSAC₂₀₁₀, there was an association between 25(OH)D concentrations at week 24 in pregnancy and at age 6 months in childhood (n = 633): estimate (95% CI); 0.114 (0.041;0.187), p = 0.002, and between 25(OH)D at age 6 months and 6 years (n = 475): 0.155 (0.083;0.228), p < 0.001. This was also demonstrated in the COPSAC₂₀₀₀ cohort between 25(OH)D concentrations in cord blood and at age 4 years (n = 188): 0.294 (0.127;0.461), p < 0.001 and at age 6 months and 4 years (n = 264): 0.260 (0.133;0.388), p < 0.001. In COPSAC₂₀₀₀, we also found an association between hs-CRP at age 6 months and 12 years in childhood (n = 232): 0.183 (0.076;0.289), p < 0.001. Finally, we found a negative association between the cross-sectional measurements of 25(OH)D and hs-CRP at age 6 months (n = 613) in COPSAC₂₀₁₀: −0.004 (−0.008;−0.0004), p = 0.030, but this was not replicated in COPSAC₂₀₀₀. In this study, we found evidence of associations across timepoints of 25(OH)D concentrations from mid-pregnancy to infancy and through childhood and associations between hs-CRP levels during childhood, although with weak correlations. We also found a negative cross-sectional association between 25(OH)D and hs-CRP concentrations in COPSAC₂₀₁₀ proposing a role of vitamin D in systemic low-grade inflammation, though this association was not present in COPSAC₂₀₀₀.

A Biological Index to Screen Multi-Micronutrient Deficiencies Associated with the Risk to Develop Dementia in Older Persons from the Community

BACKGROUND

Low blood status in several nutritional compounds, including long-chain omega-3 fatty acids (LC n-3 PUFA), carotenoids, and vitamin D, have been associated with a higher risk to develop dementia. Nutritional deficiencies may potentiate each other regarding dementia risk; yet the association of multiple nutritional deficiencies with dementia has been little explored.

OBJECTIVE

To develop an index of micronutritional biological status (MNBS) for the screening of multi-micronutritional deficiencies associated with the risk of dementia in a prospective population-based cohort of older persons.

METHODS

We included participants from the Bordeaux Three-City study, who were free of dementia at baseline, had blood measurements of LC n-3 PUFA, carotenoids, and 25(OH)D, and who were followed for up to 18 years for dementia. We used penalized splines in Cox models to model dose-response relationships of each nutritional component with the risk of dementia and construct a risk index.

RESULTS

629 participants with an average age of 73.1 years were included in the study. Each increase of 1 SD of the MNBS index was associated with a 46%higher risk of dementia (HR = 1.46, 95%CI 1.23; 1.73). Participants with highest index ([mean+1SD; max]) had a 4-fold increased risk of dementia compared with participants with a low index ([min; mean-1SD]) (HR = 4.17, 95%CI 2.30; 7.57).

CONCLUSION

This index of assessment of micronutritional biological status is a practical tool that may help identify populations with inadequate nutritional status, screen eligible individuals for nutritional prevention in primary care, or for supplementation in preventive trials of dementia.

Association between circulating 25-hydroxyvitamin D concentrations and hip replacement for osteoarthritis: a prospective cohort study

BACKGROUND

To examine the association between circulating 25(OH)D concentrations and incidence of total hip replacement for osteoarthritis in a prospective cohort study.

METHODS

This study examined a random sample of 2651 participants in the Melbourne Collaborative Cohort Study who had 25(OH)D concentrations measured from dried blood spots collected in 1990-1994. Participants who underwent total hip replacement for osteoarthritis between January 2001 and December 2018 were identified by linking the cohort records to the Australian Orthopaedic Association National Joint Replacement Registry. Cox proportional hazard regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) of total hip replacement for osteoarthritis in relation to 25(OH)D concentrations, adjusted for confounders.

RESULTS

Eighty-six men and eighty-seven women had a total hip replacement for osteoarthritis. Compared with men in the lowest (1st) quartile of 25(OH)D concentration, the HR for total hip replacement was 2.32 (95% CI 1.05, 5.13) for those in the 2nd quartile, 2.77 (95% CI 1.28, 6.00) for those in the 3rd quartile, and 1.73 (95% CI 0.75, 4.02) for those in the highest quartile of 25(OH)D concentrations (p for trend 0.02). There was little evidence of an association in women.

CONCLUSIONS

Higher circulating 25(OH)D concentrations were associated with an increased risk of total hip replacement for osteoarthritis in men but not in women. Although the underlying mechanism warrants further investigation, our findings highlight the need to determine the optimal levels of circulating 25(OH)D to reduce the risk of hip osteoarthritis.

Association Between Serum 25-hydroxyvitamin D Concentrations and Mortality Among Adults With Prediabetes

OBJECTIVES

To investigate the association of circulating 25-hydroxyvitamin D [25(OH)D] levels with mortality among adults with prediabetes.

METHODS

This retrospective cohort study included 15,195 adults with prediabetes (aged ≥20 years) from the National Health and Nutrition Examination Survey (NHANES) III and NHANES 2001-2014. Mortality from all causes, cardiovascular disease (CVD), and cancer was linked to National Death Index mortality data.

RESULTS

The median (interquartile range) concentration of serum 25(OH)D was 60.5 (45.3, 77.4) nmol/L, and only 23.1% had sufficient vitamin D (≥75 nmol/L). Elevated serum 25(OH)D concentrations were significantly associated with lower levels of insulin, homeostasis model assessment of insulin resistance, triglyceride, and C-reactive protein, and higher levels of high-density lipoprotein at baseline (all Ptrend < 0.05). During a median follow up of 10.7 years, 3765 deaths (including 1080 CVD deaths and 863 cancer deaths) were identified. Compared with participants with 25(OH)D <30 nmol/L, the multivariate-adjusted hazard ratios and 95% confidence intervals for participants with 25(OH)D ≥ 75 nmol/L were 0.66 (0.53, 0.82) for all-cause mortality (Ptrend < 0.001), 0.66 (0.48, 0.89) for CVD mortality (Ptrend = 0.001), and 0.82 (0.49, 1.35) for cancer mortality (Ptrend = 0.32). For per-unit increment in ln-transformed 25(OH)D, there was a 27% lower risk of all-cause mortality and a 34% lower risk of CVD mortality (both P < 0.01).

CONCLUSIONS

These findings suggested that higher serum 25(OH)D concentrations were associated with lower all-cause and CVD mortality among individuals with prediabetes.

Decreasing prevalence of vitamin D deficiency in the central region of Saudi Arabia (2008-2017)

OBJECTIVE

Widespread vitamin D deficiency (serum 25-hydroxyvitamin D < 50 nmol/L) in Saudi Arabia (SA) has been documented, yet a time trend is needed to establish where the prevalence is headed. This study aims to fill this gap.

STUDY DESIGN AND SETTING

This cross-sectional series (N = 7360) were conducted in the central region of SA from 2008 to 2017. Participants of all ages were taken from multiple cohorts that included the Biomarker Screening in Riyadh (2008-2010; N = 1460), the Osteoporosis Registry (2014-2017; N = 1225), Gestational Diabetes Mellitus cohort (2014-2017, N = 281), Vitamin D School Project (2011-2017; N = 3039) and Prediabetes cohort (2012-2017; N = 1355) master databases.

RESULTS

Vitamin D deficiency in SA has a 10-year prevalence of 73.2 %. Between 2008-2017, the prevalence of vitamin D deficiency decreased from 87.1% to 64.7% for participants aged 18-40 years (p-trend<0.001), and from 86.2% to 45.7% in participants aged > 40 years (p-trend<0.001). During this period, vitamin D deficiency in females decreased from 80.1% to 69.6% (p-trend<0.001), whereas in males, it decreased from 93.2% to 49.3% (p-trend<0.001). Serum 25(OH)D was observed to have an overall increase of 2.2 ± 0.1 nmol/l (p < 0.001) along with the seasonally adjusted annual increase of 1.3 ± 0.2 nmol/l from 2008 to 2017 (p < 0.001).

CONCLUSION

The decreasing trend in vitamin D deficiency in SA across all demographics suggests successful public health campaigns over time. It will be interesting to investigate further whether the general improvement in the vitamin D status at the community level also translated in lesser incidences of vitamin d-related diseases over time.

Population Vitamin D Stores Are Increasing in Tasmania, and This Is Associated With Less BMD Loss Over 10 Years

CONTEXT

Vitamin D deficiency is a common, modifiable determinant of musculoskeletal health.

OBJECTIVE

There are limited data that examine the longitudinal change in population 25-hydroxyvitamin D (25[OH]D) and none that evaluate the long-term skeletal outcomes of longitudinal vitamin D status.

METHODS

A prospective cohort analysis was conducted of community-dwelling adults aged 50 to 80 years who had 25(OH)D assessed by radioimmunoassay and bone mineral density (BMD) by dual-energy x-ray absorptiometry at baseline (n = 1096), 2.5 (n = 870), and 10 (n = 565) years. Sun exposure was quantified by questionnaire and supplement use at clinic review. 25(OH)D less than 50 nmol/L was considered deficient. Participants were provided with their 25(OH)D results.

RESULTS

Over 10 years 25(OH)D increased (52.2 ± 17.0 to 63.5 ± 23.6 nmol/L, P < .001). Participants with baseline deficiency had larger 25(OH)D increases than baseline sufficient participants (19.2 ± 25.3 vs 1.6 ± 23.3 nmol/L, P < .001). Longitudinal change in 25(OH)D was associated with baseline summer (β = 1.46, P < .001) and winter (β = 1.29, P = .003) sun exposure, change in summer (β = 1.27, P = .002) and winter (β = 1.47, P < .001) sun exposure, and vitamin D supplement use (β = 25.0-33.0, P < .001). Persistent vitamin D sufficiency was associated with less BMD loss at the femoral neck (β = 0.020, P = .027), lumbar spine (β = 0.033, P = .003), and total hip (β = 0.023, P = .021) compared to persistent vitamin D deficiency. Achieving vitamin D sufficiency was associated with less BMD loss at the lumbar spine (β = 0.045, P < .001) compared to persistent vitamin D deficiency.

CONCLUSIONS

Population 25(OH)D concentration increased because of a combination of increased sun exposure and supplement use. Maintaining or achieving vitamin D sufficiency was associated with less BMD loss over 10 years.

A prospective study into change of vitamin D levels, depression and frailty among depressed older persons

OBJECTIVES

While vitamin D is involved in frailty as well as depression, hardly any study has examined the course of vitamin D levels prospectively. The objective of this study is to examine whether a change of vitamin D in depressed older adults is associated with either depression course, course of frailty, or both.

METHODS

The study population consisted of 232 of 378 older adults (60-93 years) with a DSM-IV defined depressive disorder participating in the Netherlands Study of Depression in Older persons, a prospective clinical cohort study. Baseline and 2-year follow-up data on depressive disorder (DSM-IV diagnosis), symptom severity (inventory of depressive symptoms), frailty phenotype (and its individual components) and vitamin D levels were obtained. Linear mixed models were used to study the association of change in vitamin D levels with depression course, course of frailty, and the combination.

RESULTS

Vitamin D levels decreased from baseline to follow-up, independent from depression course. An increase in frailty was associated with a significantly sharper decrease of vitamin D levels over time. Post hoc analyses showed that this association with frailty might be driven by an increase of exhaustion over time and counteracted by an increase in walking speed.

CONCLUSIONS

Our findings generate the hypothesis that vitamin D supplementation in late-life depression may improve frailty, which may partly explain inconsistent findings of randomised controlled trials evaluating the effect of vitamin D for depression. We advocate to consider frailty (components) as an outcome in future supplementation trials in late-life depression.

The determinants and longitudinal changes in vitamin D status in middle-age: a Northern Finland Birth Cohort 1966 study

PURPOSE

Populations living in the Nordic countries are at high risk for vitamin D (VitD) deficiency or insufficiency. To reduce the risk, nationwide interventions based on food fortification and supplementation are being implemented. However, there is limited evidence about the impact of such public health campaigns on target populations.

METHODS

We studied an unselected sample of 3650 participants (56.2% females) from the longitudinal Northern Finland Birth Cohort 1966 with repeated measures of serum 25-hydroxyvitamin D [25(OH)D] at ages 31 (1997) and 46 (2012-2013). Timepoints corresponded to the period before and during the food fortification. We examined the effect of VitD intake from the diet and supplementation, body mass index and previous 25(OH)D concentration on 25(OH)D concentration at 46 years using a multivariable linear regression analysis. A 25(OH)D z score adjusted for sex, season, latitude and technical effect was used in the analysis.

RESULTS

We observed an increase of 10.6 nmol/L in 25(OH)D, when the baseline 25(OH)D was 54.3 nmol/L. The prevalence of serum 25(OH)D below < 50 nmol/L was halved. The changes were found for both sexes and were more pronounced in winter compared to summer months. Regular VitD supplementation had a significant positive effect on 25(OH)D at the age of 46, as well as had the dietary intake of fortified dairy products and fish, and the previous 25(OH)D concentration. However, the intake of fat-spreads albeit VitD-fortified, did not predict 25(OH)D.

CONCLUSION

Our results demonstrated the positive impact of the fortification programme on VitD status in middle-aged population.

Vitamin D and Vitamin D-binding protein and risk of bladder cancer: A nested case-control study in the Norwegian Janus Serum Bank Cohort

Background

 High circulating levels of vitamin D (25(OH)D) are suggested to reduce the risk of urinary bladder cancer (BC), but the evidence is weak, and several studies lack sufficient adjustment for potential confounders (e.g., smoking, body mass index (BMI), and physical activity). Moreover, few studies have investigated the role of vitamin D‐binding protein (DBP) in this context. We conducted a matched nested case–control study including 378 cases and 378 controls within the Norwegian population‐based Janus cohort, using serum collected 5–41 years prior to diagnosis, to study 25(OH)D and BC risk, by taking circulating DBP into account.

Methods

Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), for 25(OH)D, DBP, and the molar ratio of 25(OH)D:DBP, an estimate of unbound (free) 25(OH)D levels. We adjusted for smoking (status and pack‐years), BMI, physical activity, education and (mutually) for 25(OH)D and DBP. Restricted cubic splines were employed to examine nonlinear associations.

Results

High optimal levels of circulating 25(OH)D (≥100 nmol/L) (HR 0.35, 95% CI 0.19–0.64) were associated with decreased BC risk, when compared with insufficient concentrations (50–74 nmol/L). This association was less pronounced for optimal levels (75–99 nmol/L) (HR = 0.69, 95% CI 0.47–1.01). Moreover, estimated free 25(OH)D, was associated with decreased BC risk for molar ratio 17–21 (HR 0.66, 95% CI 0.44–0.97) and ≥22 (HR 0.50, 95% CI 0.29–0.82), compared to molar ratio 11–16. The HR function for BC risk was not linear, rather reversed u‐shaped, with the highest HR at 62.5 nmol/L and 13.5 molar ratio, respectively.

Conclusion

High levels of total and estimated free 25(OH)D were associated with reduced risk of BC, compared with insufficient concentrations. DBP was not associated with BC risk. We did not observe any impact of DBP or any of the studied lifestyle factors on the association between 25(OH)D and BC.