Serum 25-Hydroxyvitamin D and Cancer Risk in Older Adults: Results from a Large German Prospective Cohort Study

Vitamin D intake, blood 25(OH)D levels, and breast cancer risk or mortality: a meta-analysis

Background:

Experimental studies suggest potential anti-carcinogenic properties of vitamin D against breast cancer risk, but the epidemiological evidence to date is inconsistent.

Methods:

We searched MEDLINE and EMBASE databases along with a hand search for eligible studies to examine the association between vitamin D status (based on diet and blood 25-hydroxyvitamin D (25(OH)D)) and breast cancer risk or mortality in a meta-analysis. A random-effect model was used to calculate a pooled adjusted relative risk (RR).

Results:

A total of 30 prospective studies (nested case-control or cohort) were included for breast cancer incidence (n=24 studies; 31 867 cases) or mortality (n=6 studies; 870 deaths) among 6092 breast cancer patients. The pooled RRs of breast cancer incidence for the highest vs the lowest vitamin D intake and blood 25(OH)D levels were 0.95 (95% CI: 0.88–1.01) and 0.92 (95% CI: 0.83–1.02), respectively. Among breast cancer patients, high blood 25(OH)D levels were significantly associated with lower breast cancer mortality (pooled RR=0.58, 95% CI: 0.40–0.85) and overall mortality (pooled RR=0.61, 95% CI: 0.48–0.79). There was no evidence of heterogeneity and publication bias.

Conclusions:

Our findings suggest that high vitamin D status is weakly associated with low breast cancer risk but strongly associated with better breast cancer survival.

Is vitamin D deficiency a cause of increased morbidity and mortality at older age or simply an indicator of poor health?

To assess whether vitamin D deficiency is a cause of increased morbidity and mortality or simply an indicator of poor health, we assessed (1) the cross-sectional and longitudinal association of vitamin D deficiency with self-rated health (SRH) and frailty and (2) the association of vitamin D deficiency with mortality, with and without control for SRH and frailty. Analyses were performed in 9,579 participants of the German, population-based ESTHER cohort (age-range at baseline: 50-74 years), with follow-ups after 2, 5 and 8 years (mortality: 12 years). During follow-up, 129 subjects newly reported poor SRH, 510 developed frailty and 1,450 died. In cross-sectional analyses, subjects with vitamin D deficiency had higher odds of a poor SRH and frailty but no association with SRH or frailty was observed in longitudinal analyses. The association of vitamin D deficiency with all-cause and several cause-specific mortalities was strong and unaltered by time-dependent adjustment for classic mortality risk factors, SRH and frailty. In conclusion, vitamin D deficiency may not cause frailty or poor general health but may nevertheless be a prognostic marker for mortality, independent of the individual's morbidity.

Serum 25-hydroxyvitamin D predicts the short-term outcomes of Chinese patients with acute ischaemic stroke

Low vitamin D levels have been reported to contribute to the risk of cardiovascular events and mortality, especially stroke. In the present study we therefore evaluated the short-term prognostic value of serum 25(OH)D (25-hydroxyvitamin D) in Chinese patients with AIS (acute ischaemic stroke). From February 2010 to September 2012, consecutive stroke patients admitted to the emergency department at two hospitals in Beijing, China were identified. Clinical information was collected, and the serum concentration of 25(OH)D and NIHSS (National Institutes of Health Stroke Scale) were measured at the time of admission. Short-term functional outcome was measured using a modified Rankin Scale (mRS) at 90 days after admission. Multivariate analyses were performed using logistic regression models. During the inclusion period, 231 patients were diagnosed as having AIS, and 220 completed follow-up. The median serum 25(OH)D level was significantly lower in patients with AIS compared with normal controls [14.2 (10.2-18.9) ng/ml compared with 17.9 (12.5-22.9) ng/ml; P<0.001; values are medians (interquartile range)]. 25(OH)D was an independent prognostic marker of short-term functional outcome and death {0.79 (0.73-0.85) and 0.70 (0.50-0.98) respectively [values are odds rations (95% confidence intervals)]; P<0.01 for both, adjusted for NHISS, other predictors and vascular risk factors} in patients with AIS. In ROC (receiver operating characteristic) curve analysis, the prognostic accuracy of 25(OH)D was higher compared with all of the other serum predictors and was in the range of NIHSS score. In conclusion, these findings suggest that 25(OH)D is an independent prognostic marker for death and functional outcome within 90 days in Chinese patients with AIS even after adjusting for possible confounding factors.

Vitamin D binding protein: a multifunctional protein of clinical importance

Since the discovery of group-specific component and its polymorphism by Hirschfeld in 1959, research has put spotlight on this multifunctional transport protein (vitamin D binding protein, DBP). Besides the transport of vitamin D metabolites, DBP is a plasma glycoprotein with many important functions, including sequestration of actin, modulation of immune and inflammatory responses, binding of fatty acids, and control of bone development. A considerable DBP polymorphism has been described with a specific allele distribution in different geographic area. Multiple studies have shed light on the interesting relationship between polymorphisms of the DBP gene and the susceptibility to diseases. In this review, we give an overview of the multifunctional character of DBP and describe the clinical importance of DBP and its polymorphisms. Finally, we discuss the possibilities to use DBP as a novel therapeutic agent.

[Epidemiological research with data from cancer registries: a program financed by the German Cancer Aid (Deutsche Krebshilfe, DKH)]

In 2007, the German Cancer Aid started a program to promote epidemiological research with data from cancer registries. Within this program, ten projects with various epidemiological research questions were funded. The program was a major boost for the use of data from population-based cancer registries and was an important milestone for cancer epidemiology in Germany.

Circulating 25-hydroxyvitamin D serum concentration and total cancer incidence and mortality: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis of longitudinal studies on the association of 25(OH)D with total cancer incidence and mortality.

METHOD

Relevant longitudinal observational studies were identified by systematically searching Ovid Medline, EMBASE, and ISI Web of Knowledge databases. Due to the heterogeneity across studies in categorizing 25(OH)D concentration, all results were recalculated for an increase of 25(OH)D by 50 nmol/L.

RESULTS

In meta-analyses with random effects models, the summary risk ratios and confidence intervals (RRs (95% CI)) for the association of an increase of 25(OH)D by 50 nmol/L with total cancer incidence (5 studies) and mortality (13 studies) were 0.89 (0.81, 0.97) and 0.83 (0.71, 0.96), respectively. In sex-specific analyses no significant association with total cancer incidence was observed among men or women. A clear inverse association with total cancer mortality was observed among women (0.76 (0.60, 0.98)) but not among men (0.92 (0.65, 1.32)). Large heterogeneity was observed for studies on total cancer mortality (P<0.01) but not for studies on cancer incidence (P=0.41). No publication bias was found.

CONCLUSION

The meta-analysis suggests a moderate inverse association of 25(OH)D concentration with total cancer incidence and mortality.

Serum 25-hydroxyvitamin D and breast cancer risk: a meta-analysis of prospective studies

There were some case-control studies, nested case-control studies, and cohort studies with controversial results on the association between serum 25-hydroxyvitamin D [25(OH)D] and breast cancer risk. Case-control studies are prone to selection bias, which limit the strength and quality of the evidence. To overcome the shortcoming of the case-control studies, the meta-analysis of prospective studies including nested case-control studies and cohort studies was conducted. PubMed, Embase, and Web of Science databases were searched, and the last retrieval date was March 24, 2013. For the highest versus the lowest level of serum 25(OH)D, the relative risks (RRs) and its 95% confidence intervals (CIs) from each study were used to estimate summary RR and its 95% CI. Subgroup analyses by geographic region, menopausal status, and adjusted status of RR were also performed, respectively. A dose-response association between serum 25(OH)D concentration and breast cancer risk was assessed. Fourteen articles with 9,110 breast cancer cases and 16,244 controls were included in the meta-analysis. Overall, serum 25(OH)D levels were inversely significantly associated with breast cancer risk (RR = 0.845, 95% CI = 0.750-0.951). Inversely statistically significant associations were observed in North American studies, postmenopausal women, and studies with adjusted and unadjusted RR, respectively. No statistically significant associations were observed in European studies and premenopausal women, respectively. Dose-response analysis showed that every 10 ng/mL increment in serum 25(OH)D concentration was associated with a significant 3.2% reduction in breast cancer risk. This meta-analysis provides evidence of a significantly inverse association between serum 25(OH)D concentration and breast cancer risk.