Association of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and parathyroid hormone with mortality among middle-aged and older European men

Associations of 25-hydroxyvitamin D status and vitamin D supplementation use with mortality due to 18 frequent cancer types in the UK Biobank cohort

BACKGROUND

Although the associations of serum 25-hydroxyvitamin D (25(OH)D) levels and vitamin D supplementation with total cancer mortality are well-known, evidence regarding the association of 25(OH)D and cancer site-specific mortality is predominantly limited to common cancer types, and most studies on vitamin D supplementation use have limitations on sample size and the adjustment of important confounding factors.

METHODS

We used cause-specific Cox regression models adjusted for 48 covariates to assess the associations of vitamin D deficiency, insufficiency, and vitamin D supplementation use with mortality from any cancer and 18 specific cancers in 411,436 United Kingdom Biobank participants, aged 40-69 years.

RESULTS

The majority of the study population had either vitamin D deficiency (21.1%) or insufficiency (34.4%). Furthermore, 4.1% and 20.3% of the participants regularly took vitamin D or multivitamin supplements, respectively. During a median follow-up of 12.7 years, vitamin D deficiency was associated with significantly increased mortality from total cancer and four specific cancers: stomach (hazard ratio, 95% confidence interval: 1.42, 1.05-1.92), colorectal (1.27, 1.07-1.50), lung (1.24, 1.10-1.40), and prostate (1.36, 1.06-1.75). Vitamin D insufficiency was associated with increased colorectal (1.14, 1.00-1.30) and lung cancer mortality (1.19, 1.08-1.32). Compared to non-users, vitamin D use was associated with lower lung cancer (0.75, 0.60-0.95) and total cancer mortality. Multivitamin use was associated with lower mortality from melanoma (0.64, 0.43-0.97).

CONCLUSION

Vitamin D deficiency and insufficiency were associated with increased mortality from multiple common cancers. The potential to reduce cancer mortality by vitamin D supplementation in populations with low 25(OH)D levels should be further explored.

Circulating Vitamin D Level and Risk of Sudden Cardiac Death and Cardiovascular Mortality: A Dose-Response Meta-Analysis of Prospective Studies

BACKGROUND

We conducted a comprehensive meta-analysis of prospective cohort studies to analyze the effect of circulating vitamin D level on the risk of sudden cardiac death (SCD) and cardiovascular disease (CVD) mortality.

METHODS

Prospective cohort studies evaluating the association between circulating vitamin D and risk of SCD and CVD mortality were systematically searched in the PubMed and Embase. Extracted data were analyzed using a random effects model and results were expressed in terms of hazard ratio (HR) and 95% confidence interval (CI). Restricted cubic spline analysis was used to estimate the dose-response relationships.

RESULTS

Of the 1,321 records identified using the search strategy, a total of 19 cohort studies were included in the final meta-analysis. The pooled estimate of HR (95% CI) for low vs. high circulating vitamin D level was 1.75 (1.49-2.06) with I² value of 30.4%. In subgroup analysis, strong effects of circulating vitamin D were observed in healthy general population (pooled HR, 1.84; 95% CI, 1.43-2.38) and the clinical endpoint of SCD (pooled HRs, 2.68; 95% CI, 1.48-4.83). The dose-response analysis at the reference level of < 50 nmol/L showed a significant negative association between circulating vitamin D and risk of SCD and CVD mortality.

CONCLUSION

Our meta-analysis of prospective cohort studies showed that lower circulating vitamin D level significantly increased the risk of SCD and CVD mortality.

Aging Men With Insufficient Vitamin D Have a Higher Mortality Risk: No Added Value of its Free Fractions or Active Form

CONTEXT

Low total 25-hydroxyvitamin D (25(OH)D) has been associated with mortality. Whether vitamin D in its free form or 1,25-dihydroxyvitamin D (1,25(OH)2D), provide any additional information is unclear.

OBJECTIVE

To determine what level of 25(OH)D is predictive for mortality and if free 25(OH)D or 1,25(OH) 2 D concentrations have any added value.

METHODS

This prospective cohort comprised 1915 community-dwelling men, aged 40 to 79 years. Intervention included determination of association of total and free 25(OH)D and 1,25(OH) 2 D concentrations with survival status. Vitamin D results were grouped into quintiles. For total 25(OH)D, specific cutoff values were also applied. Cox proportional hazard models were used adjusted for center, body mass index, smoking, alcohol, physical activity, season of blood sample, kidney function, and number of comorbidities.

RESULTS

A total of 469 (23.5%) men died during a mean follow-up of 12.3 ± 3.4 years. Compared to those with normal vitamin D values (> 30 µg/L), men with a total 25(OH)D of less than 20 µg/L had an increased mortality (hazard ratio [HR] 2.03 [95% CI, 1.39-2.96]; P < .001). Likewise, men in the lowest 3 free 25(OH)D quintiles (< 4.43 ng/L) had a higher mortality risk compared to the highest quintile (HR 2.09 [95% CI, 1.34-3.25]; P < .01). Mortality risks were similar across all 1,25(OH)2D and vitamin D binding protein quintiles.

CONCLUSION

Aging men with vitamin D deficiency have a 2-fold increased mortality risk. Determinations of either the free fractions of vitamin D or measurement of its active form offer no additional information on mortality risks.

Circulating 25-hydroxy-vitamin D and the risk of cardiovascular diseases. Systematic review and meta-analysis of prospective cohort studies

AIMS

Circulating vitamin D is linked with the risk of cardiovascular disease (CVD). A meta-analysis has yet to explicitly explore correlation between vitamin D and the risk of CVD incidence and recurrent CVD. This meta-analysis examines the association between 25-hydroxy-vitamin D (25(OH)D) and the risk of CVD incidence (fatal, non-fatal, fatal and non-fatal combined events) and the risk of recurrent CVD (fatal, recurrent, and fatal and recurrent combined events). PROSPERO registration-CRD42021251483.

DATA SYNTHESIS

A total of 79 studies (46 713 CVD cases in 1 397 831 participants) were included in the meta-analysis, of which 61 studies examined the risk of CVD incidence events, and 18 studies examined risk of recurrent CVD events. The risk of CVD incidence events (RR = 1.34, 95% CI: 1.26-1.43, p < 0.001) and recurrent CVD events (RR = 1.86, 95% CI: 1.46-2.36, p < 0.001) was higher in the lowest than the highest category of circulating 25(OH)D. Dose-response analysis reported a linear association for every 10 ng/ml increment of 25(OH)D and non-fatal CVD incidence events (RR = 0.94; 95% CI = 0.89-0.98, p = 0.005), lower fatal recurrent CVD events (RR = 0.45; 95% CI = 0.32-0.62, p < 0.001) and lower combined recurrent CVD events (RR = 0.80; 95% CI = 0.65-0.97, p = 0.023). A non-linear association was observed between higher 25(OH)D and lower fatal CVD incidence events (P-nonlinear<0.001), lower combined CVD incidence events (P-nonlinear = 0.001), and lower non-fatal recurrent CVD events (P-nonlinear = 0.044).

CONCLUSIONS

The lowest category of circulating 25(OH)D was associated with a higher risk of CVD incidence events and recurrent CVD events.

Racial/Ethnic Differences in 25-Hydroxy Vitamin D and Parathyroid Hormone Levels and Cardiovascular Disease Risk Among Postmenopausal Women

Background

Recent evidence suggests that racial/ethnic differences in circulating levels of free or bioavailable 25‐hydroxy vitamin D (25[OH]D) rather than total 25(OH)D may explain apparent racial disparities in cardiovascular disease (CVD). We prospectively examined black‐white differences in the associations of total, free, and bioavailable 25(OH)D, vitamin D–binding protein, and parathyroid hormone levels at baseline with incident CVD (including nonfatal myocardial infarction, nonfatal stroke, and CVD death) in postmenopausal women.

Methods and Results

We conducted a case‐cohort study among 79 705 postmenopausal women, aged 50 to 79 years, who were free of CVD at baseline in the WHI‐OS (Women's Health Initiative Observational Study). A subcohort of 1300 black and 1500 white participants were randomly chosen as controls; a total of 550 black and 1500 white women who developed incident CVD during a mean follow‐up of 11 years were chosen as cases. We directly measured total 25(OH)D, vitamin D–binding protein, albumin, parathyroid hormone, and calculated free and bioavailable 25(OH)D. Weighted Cox proportional hazards models were used to examine their associations with CVD risk. Although vitamin D–binding protein and total, free, and bioavailable 25(OH)D were not significantly associated with CVD risk in black or white women, a significant positive association between parathyroid hormone and CVD risk persisted in white women (hazard ratio comparing the highest quartile with the lowest, 1.37; 95% CI, 1.06–1.77) but not in black women (hazard ratio comparing the highest quartile with the lowest, 1.12; 95% CI, 0.79–1.58), independent of total, free, and bioavailable 25(OH)D or vitamin D–binding protein.

Conclusions

Circulating levels of vitamin D biomarkers are not related to CVD risk in either white or black women. Higher parathyroid hormone levels may be an independent risk factor for CVD in white women.

The association between circulating 25-hydroxyvitamin D and cardiovascular diseases: a meta-analysis of prospective cohort studies

BACKGROUND

There is a controversy about the association between vitamin D and cardiovascular diseases (CVDs). The effect of serum 25-OH-vitD on the risk of CVDs was evaluated.

METHODS

Major electronic databases including Scopus, Science Direct, and PubMed were searched. All prospective cohort studies on the relationship between vitamin D status and CVDs conducted between April 2000 and September 2017 were included, regardless language. The study participants were evaluated regardless of their age, sex, and ethnicity. The Newcastle-Ottawa Scale was used to assess the quality of the studies. Two investigators independently selected the studies and extracted the data. The designated effects were risk ratio (RR) and hazard ratio (HR). The random effects model was used to combine the results.

RESULTS

A meta-analysis of 25 studies with 10,099 cases of CVDs was performed. In general, a decrease in the level of vitamin D was associated with a higher relative risk of CVDs (incidence-mortality combined) (RR = 1.44, 95% CI: 1.24-1.69). This accounts for 54% of CVDs mortality rate (RR = 1.54, 95% CI: 1.29-1.84(. However, no significant relationship was observed between the vitamin D status and incidence of CVDs (RR = 1.18, 95% CI: 1-1.39). In general, low serum vitamin D level increased the risk of CVD by 44% (RR = 1.44, 95% CI: 1.24-1.69). It also increased the risk of CVD mortality (RR = 1.54, 95% CI: 1.29-1.84) and incidence rates (RR = 1.18, 95% CI: 1-1.39).

CONCLUSIONS

The findings showed that vitamin D deficiency increases the CVDs mortality rate. Due to the limited number of studies on patients of the both genders, further research is suggested to separately evaluate the effect of vitamin D status on CVD in men and women.

25-Hydroxyvitamin D and Total Cancer Incidence and Mortality: A Meta-Analysis of Prospective Cohort Studies

Epidemiological studies have suggested inconclusive associations between 25-hydroxyvitamin D and total cancer incidence and mortality. The aim of this study was to quantitatively assess these associations by combining results from prospective cohort studies. A systematic literature search was implemented in PubMed and Scopus databases in April 2019. Comparing the highest with the lowest categories, the multivariate-adjusted relative risks (RRs) and the corresponding 95% confidence intervals (CIs) were pooled using a random-effects model. A trend estimation was performed using a two-stage, dose-response, meta-analysis method. Twenty-three independent prospective studies were included for data synthesis. Eight studies investigated the association between 25-hydroxyvitamin D and the risk of cancer incidence (7511 events and 70,018 participants), and the summary estimate showed that 25-hydroxyvitamin D is marginally associated with cancer risk (Summary RR = 0.86; 95% CI: 0.73, 1.02; I² = 70.8%; p = 0.001). Sixteen studies investigated the association between 25-hydroxyvitamin D and the risk of cancer mortality (8729 events and 101,794 participants), and a higher 25-hydroxyvitamin D concentration was inversely associated with the risk of cancer mortality (Summary RR = 0.81; 95% CI: 0.71, 0.93; I² = 48.8%, p = 0.012). Dose-response analysis indicated that the risk of cancer incidence was reduced by 7% (RRs = 0.93; 95% CI: 0.91, 0.96), and the risk of cancer mortality was reduced by 2% (RRs = 0.98; 95% CI: 0.97, 0.99), with each 20 nmol/L increment of 25-hydroxyvitamin D concentration. This meta-analysis provides evidence that a higher 25-hydroxyvitamin D concentration is associated with a lower cancer incidence and cancer mortality.

Serum level vitamin D and parathyroid hormone, and mortality, with or without chronic kidney disease

Levels of vitamin D and parathyroid hormone (PTH) are closely associated with renal function. We evaluated the associations among 25-hydroxyvitamin D (25OHD) levels, PTH levels, and mortality, and whether these associations varied by renal function. We used data from the Dong-gu Study, a population-based cohort in Korean adults. We analyzed the associations among intact PTH, 25OHD levels and mortality in 8580 participants. Hazard ratios (HRs) for mortality were calculated using Cox proportional hazards regression after adjusting for age, sex, month of sampling, lifestyle, and comorbidities. We also evaluated the effects of chronic kidney disease (CKD). A total of 860 deaths occurred during the follow-up period of 7.6 years. Compared to the first 25OHD quartile, the HRs of the second, third, and fourth quartiles were 0.96 [95% confidence interval (CI) 0.79-1.16], 0.84 (95% CI 0.68-1.02), and 0.71 (95% CI 0.57-0.89), respectively. The association between intact PTH levels and mortality varied by renal function, and was both nonlinear and significant only in subjects with CKD. Compared to the second intact PTH quartile in such subjects, the HRs for the first, third, and fourth quartiles were 1.61 (95% CI 0.92-2.81), 1.97 (95% CI 1.17-3.31), and 2.19 (95% CI 1.33-3.59), respectively. In conclusion, we demonstrated that low serum levels of 25OHD are associated with an increased risk of mortality. Serum levels of intact PTH are nonlinearly associated with mortality only in subjects with CKD, with the lowest risk for mortality being evident in the second quartile.

Vitamin D Status and Mortality: A Systematic Review of Observational Studies

Epidemiological evidence suggests that vitamin D deficiency is associated with increased mortality, but it is unclear whether this is explained by reverse causation, and if there are specific causes of death for which vitamin D might be important. We conducted a systematic review of observational studies investigating associations between circulating 25-hydroxyvitamin D (25(OH)D) concentration and all-cause or cause-specific mortality in generally healthy populations. Relevant studies were identified using PubMed and EMBASE searches. After screening 722 unique records and removing those that were ineligible, 84 articles were included in this review. The vast majority of studies reported inverse associations between 25(OH)D concentration and all-cause mortality. This association appeared to be non-linear, with progressively lower mortality with increasing 25(OH)D up to a point, beyond which there was no further decrease. There is moderate evidence that vitamin D status is inversely associated with cancer mortality and death due to respiratory diseases, while for cardiovascular mortality, there is weak evidence of an association in observational studies, which is not supported by the data from intervention or Mendelian randomization studies. The relationship between vitamin D status and other causes of death remains uncertain due to limited data. Larger long-term studies are required to clarify these associations.

Serum phosphate levels are related to all-cause, cardiovascular and COPD mortality in men

Hyperphosphatemia has been associated with increased mortality in chronic kidney disease but the nature of such a relation in the general population is unclear. To investigate the association between phosphate (P) levels and all-cause and cause-specific mortality, we assessed two cohorts from the Rotterdam Study, with follow-up of 14.5 (RS-I) and 10.9 (RS-II) years until January 2012 with availability of fasting phosphate levels. Deaths were classified according to International Classification of Diseases into 7 groups: cardiovascular, cancer, infections, external, dementia, chronic lung diseases and other causes. Sex-stratified Weibull and competing-risks models were adjusted for age, BMI and smoking. Hazard ratios are expressed per 1 mg/dL increase in phosphate levels. The total number of participants included 3731 (RS-I, 2154 women) and 2494 (RS-II, 1361 women) subjects. The main outcome measures were all-cause and cause-specific mortality. A significant positive association was found between phosphate and all-cause mortality in men (pooled HR (95% CI): 1.46 (1.26–1.69)) but not in women (0.90 (0.77–1.05)). In men, higher phosphate increased the risk for cardiovascular mortality (1.66 (1.29–2.14)), other causes (1.67 (1.16–2.40)) and chronic lung disease mortality (1.94 (1.02–3.72)), the latter driven by mortality due to chronic obstructive pulmonary disease (COPD) (4.44 (2.08–9.49)). No relations were found for mortality due to infections, cancer, dementia or external causes. In conclusion, serum P is associated with increased all-cause, cardiovascular and COPD mortality in men but not women. The association with COPD mortality is novel and needs further research on underlying mechanisms.

Serum 25-hydroxyvitamin D and the risk of cardiovascular disease: dose-response meta-analysis of prospective studies

Background: During the past decade, an increasing number of prospective studies have focused on the association between vitamin D and cardiovascular disease (CVD). However, the evidence on the relation between serum 25-hydroxyvitamin D [25(OH)D] and the risk of overt CVD is inconclusive.Objective: We performed a dose-response meta-analysis to summarize and prospectively quantify the RR of low serum 25(OH)D concentration and total CVD (events and mortality).Design: We identified relevant studies by searching PubMed and EMBASE up to December 2015 and by hand-searching reference lists. Prospective studies based on the general population and reported RRs and 95% CIs were included. A random-effects model was used to calculate the pooled RRs. Nonlinear association was assessed by using restricted cubic spline analyses.Results: A total of 34 publications with 180,667 participants were eligible for the meta-analysis. We included 32 publications (27 independent studies) for total CVD events and 17 publications (17 independent studies) for CVD mortality. We observed an inverse association between serum 25(OH)D and total CVD events and CVD mortality, and the pooled RRs per 10-ng/mL increment were 0.90 (95% CI: 0.86, 0.94) for total CVD events and 0.88 (95% CI: 0.80, 0.96) for CVD mortality. A nonlinear association was detected for total CVD events (P-nonlinear < 0.001) and CVD mortality (P-nonlinear = 0.022).Conclusion: Serum 25(OH)D concentration was inversely associated with total CVD events and CVD mortality from the observed studies.

Parathyroid Hormone Levels in the Prediction of Ischemic Stroke Risk

Objective. It was examined whether PTH and 25-dihydroxyvitamin D (25(OH)D) levels, together or separately, are indicators of the risk of stroke. Materials and Methods. This prospective study was performed at two centers. In the study, 100 patients diagnosed with acute ischemic stroke and 100 control individuals in the same age range were examined. In addition to neurological examination, cranial imaging, extensive routine blood chemistry, PTH, and 25(OH)D levels were evaluated in all cases. Stroke risk factors were determined. Logistic regression was used for statistical analysis. Results. A total of 60 patients and 79 control individuals were included in the study. Different estimation models were designed in order to examine the relationship between PTH and 25(OH)D levels with stroke. According to modeling results, it was determined that the most effective predictor for risk of stroke was 25(OH)D levels, followed by hypertension and PTH levels, respectively. Conclusion. PTH and 25(OH)D levels together can make important contributions to determination of stroke risk, and further investigations are needed to understand this relationship more fully.

Parathyroid hormone, cardiovascular and all-cause mortality: A meta-analysis

BACKGROUND

Inconsistent findings have reported on parathyroid hormone (PTH) concentration and cardiovascular or all-cause mortality.

OBJECTIVE

To investigate whether elevated PTH concentration was an independent predictor for cardiovascular or all-cause mortality in the general population by conducting a meta-analysis based on prospective studies.

METHOD

We searched Cochrane Library, Pubmed, and Embase databases up to June 2015. Only prospective studies evaluating serum PTH concentration and cardiovascular or all-cause mortality were included. Pooled adjust risk ratio (RR) and corresponding 95% confidence intervals (CI) were calculated for the highest vs. lowest PTH concentration.

RESULTS

Ten studies with 31,616 subjects were identified and analyzed. Compared the highest to the lowest PTH concentration, elevated serum PTH concentration increased the risk of all-cause mortality (RR 1.19; 95% CI 1.08-1.30) but not for cardiovascular mortality (RR 1.26; 95% CI 0.96-1.66). Subgroup analyses indicated that cardiovascular mortality risk appeared to be more pronounced among men (RR 1.68; 95% CI 1.05-2.67).

CONCLUSIONS

Elevated PTH concentration is an independent predictor of all-cause mortality. Elevated serum PTH concentration appears to increase risk of cardiovascular mortality among men.

Physical activity, sedentary behavior, and vitamin D metabolites

Physical activity is associated with circulating 25-hydroxyvitamin D (25(OH)D). However, the influence of activity and/or sedentary behavior on the biologically active, seco-steroid hormone 1α,25-dihydroxyvitamin D (1,25(OH)2D) is unknown. We conducted a cross-sectional analysis among ursodeoxycholic acid (UDCA) randomized trial participants (n=876) to evaluate associations between physical activity, sedentary behavior, and circulating vitamin D metabolite concentrations. Continuous vitamin D metabolite measurements and clinical thresholds were evaluated using multiple linear and logistic regression models, mutually adjusted for either 1,25(OH)2D or 25(OH)D and additional confounding factors. A statistically significant linear association between 1,25(OH)2D and moderate-vigorous physical activity per week was strongest among women (β (95% CI): 3.10 (1.51-6.35)) versus men (β (95% CI): 1.35 (0.79-2.29)) in the highest tertile of activity compared to the lowest (p-interaction=0.003). Furthermore, 25(OH)D was 1.54ng/ml (95% CI 1.09-1.98) higher per hour increase in moderate-vigorous activity (p=0.001) and odds of sufficient 25(OH)D status was higher among physically active participants (p=0.001). Sedentary behavior was not significantly associated with either metabolite in linear regression models, nor was a statistically significant interaction by sex identified. The current study identified novel associations between physical activity and serum 1,25(OH)2D levels, adjusted for 25(OH)D concentrations. These results identify the biologically active form of vitamin D as a potential physiologic mechanism related to observed population-level associations between moderate-vigorous physical activity with bone health and chronic disease risk. However, future longitudinal studies are needed to further evaluate the role of physical activity and vitamin D metabolites in chronic disease prevention.

Implementation of automated testing for 1,25-dihydroxyvitamin D: Return of experience from a core-laboratory

Measurement of 1,25(OH)2D, the most biologically active form of vitamin D, circulating levels is relevant in several physiopathological states such as chronic kidney disease, parathyroid dysfunction, sarcoidosis, and vitamin D dependent rickets. Our study determined the performances of a novel automated 1,25(OH)2D immunoassay in a core-laboratory environment. We observed satisfactory analytical performances for this assay and an excellent agreement with a well established LC-MS/MS method. Furthermore, this assay allows a reduced TAT, integration in automated core-laboratories and potential consolidation with other tests of the bone and mineral metabolism.

Measurement of 25-hydroxyvitamin D(2&3) and 1,25-dihydroxyvitamin D(2&3) by tandem mass spectrometry: A primate multispecies comparison

Vitamin D metabolites are widely studied for their roles in bone health, immune functions, and other potential physiologic roles in humans. However, the optimal blood levels of vitamin D metabolites are still unclear. Various methods for measuring vitamin D metabolites have been used and recently liquid chromatography tandem mass spectroscopy (LC-MS/MS) has been adopted as the gold standard for vitamin D metabolite measurement. Here, we report the use of LC-MS/MS to measure 25-hydroxyvitamin D (25(OH)D(2&3)), and 1,25-dihydroxyvitamin D (1,25(OH)2D(2&3)), in three laboratory nonhuman primate species: common marmoset (Callithrix jacchus), rhesus macaque (Macaca mulatta), and cynomolgus macaque (Macaca fascicularis), and compare them to humans using the same technique. The nonhuman primates showed blood levels for 25(OH)D3 and 1,25(OH)2D3 significantly higher than human values with marmosets having the highest levels. Marmoset samples showed significantly more variability among individuals than those from macaques for both metabolites, but all three nonhuman primate species exhibited large variation within species for both 25(OH)D(2&3) and 1,25(OH)2D(2&3). Marmoset females had significantly lower values than the males for 25(OH)D3, while rhesus males showed a significant decrease in 25(OH)D3 with age. The most striking finding is the variation within species for vitamin D levels even in laboratory primates that have a controlled diet, UV exposure, and in some cases, genetic constraints. Similar variation in 25(OH)D responses to a fixed dose of oral vitamin D supplementation has been reported in humans. We suggest that these species can provide primate models for examining the factors influencing variation in the levels of vitamin D necessary for human and nonhuman primate health.