Vitamin D Supplementation and Its Impact on Mortality and Cardiovascular Outcomes: Systematic Review and Meta-Analysis of 80 Randomized Clinical Trials

Insights into the Role of Vitamin D in the Prevention and Control of Cancer and Other Chronic Noncommunicable Diseases: Shedding Further Light on a Captivating Subject

Vitamin D is a hormone that humans can synthesize upon sun exposure or through a balanced and healthy diet, including vitamin D-rich foods or supplements [...].

Association Among Vitamin D Supplementation, Serum 25(OH)D Concentrations, and Mortality Risk: A Prospective Cohort Study Using NHANES 2007-2018 Data

BACKGROUND

To determine the associations among self-reported vitamin D (VD) supplementation, measured serum 25-hydroxyvitamin D (25[OH]D) concentrations, and all-cause and cause-specific mortality risks.

METHODS

Self-reported VD supplementation, serum 25(OH)D concentration, and all-cause and cause-specific mortality data from the National Health and Nutrition Examination Survey 2007-2018 were examined for 10,793 adults ≥20 years from the United States. VD dosage was categorized as <800 or ≥800 IU/d. The mortality status and causes of mortality up to 2019 were determined using the National Death Index. The relationships among VD, 25(OH)D levels, and mortality were analyzed using Cox regression before and after propensity score matching (PSM).

RESULTS

Over a median of 6.6 years, 915 deaths were recorded, 230 because of cardiovascular disease (CVD), 240 because of cancer, and 445 because of other specific causes. Mortality risk did not differ between VD <800 IU/d and ≥800 IU/d before or after PSM. However, serum 25(OH)D concentrations were statistically different before and after PSM. The upper 2 quartiles of 25(OH)D levels were associated with lower all-cause mortality, and the fourth quartile was associated with reduced other-specific mortality before and after PSM. No correlation was found between the 25(OH)D concentration and CVD- or cancer-specific mortality after PSM. The inverse 25(OH)D-mortality relationship was consistent across subgroups.

CONCLUSIONS

Based on this large cohort study, higher 25(OH)D levels are robustly associated with reduced all-cause and other specific mortality but not CVD- or cancer-specific mortality. These findings support the benefits of maintaining adequate VD status for longevity. Further research is required to elucidate these mechanisms and define the optimal VD concentration to reduce mortality. These results underscore the importance of public health strategies for preventing VD deficiency.

Chronic Kidney Disease Diets for Kidney Failure Prevention: Insights from the IL-11 Paradigm

Nearly every fifth adult in the United States and many older adults worldwide are affected by chronic kidney disease (CKD), which can progress to kidney failure requiring invasive kidney replacement therapy. In this review, we briefly examine the pathophysiology of CKD and discuss emerging mechanisms involving the physiological resolution of kidney injury by transforming growth factor beta 1 (TGFβ1) and interleukin-11 (IL-11), as well as the pathological consequences of IL-11 overproduction, which misguides repair processes, ultimately culminating in CKD. Taking these mechanisms into account, we offer an overview of the efficacy of plant-dominant dietary patterns in preventing and managing CKD, while also addressing their limitations in terms of restoring kidney function or preventing kidney failure. In conclusion, this paper outlines novel regeneration strategies aimed at developing a reno-regenerative diet to inhibit IL-11 and promote repair mechanisms in kidneys affected by CKD.

Higher Vitamin D Levels before Methotrexate Therapy Initiation Are Associated with Lower Subsequent Mortality in Patients with Rheumatoid Arthritis

(1) Vitamin D deficiency is associated with mortality in the general population and has been observed in one rheumatoid arthritis (RA) cohort. Here, we investigate the relationship between 25-hydroxyvitamin D (25(OH)D) levels before methotrexate (MTX) therapy initiation in patients with RA and the subsequent all-cause mortality in a national Veterans Affairs (VA) cohort. (2) This is a retrospective study on RA patients time-oriented around the initial MTX prescription and 25(OH)D levels before starting MTX. We examined survival in patients with 25(OH)D levels > 50 nmol/L and ≤50 nmol/L using the Cox Proportional Hazard Model and fully adjusted for risk factors. (3) In total, 15,109 RA patients were included in the nationwide cohort. RA patients with 25(OH)D levels > 50 nmol/L before starting MTX had a 28% reduced risk of mortality when compared to those with levels ≤ 50 nmol/L (HR: 0.72, CI: 0.64-0.80, p < 0.001) after adjusting for traditional risk factors. (4) In this national RA cohort receiving standard-of-care MTX, patients with 25(OH)D levels > 50 nmol/L have a lower subsequent mortality when compared to those with 25(OH)D levels ≤ 50 nmol/L. It remains to be determined whether increasing Vitamin D levels in RA patients initially found to be Vitamin D deficient impacts their all-cause mortality.

Vitamin D Supplementation: A Review of the Evidence Arguing for a Daily Dose of 2000 International Units (50 µg) of Vitamin D for Adults in the General Population

Vitamin D deficiency is considered a public health problem due to its worldwide high prevalence and adverse clinical consequences regarding musculoskeletal health. In addition, vitamin D may also be crucial for the prevention of certain extraskeletal diseases. Despite decades of intensive scientific research, several knowledge gaps remain regarding the precise definition of vitamin D deficiency and sufficiency, the health benefits of improving vitamin D status, and the required vitamin D intakes. Consequently, various societies and expert groups have released heterogeneous recommendations on the dosages for vitamin D supplementation. In this brief narrative review, we outline and discuss recent advances regarding the scientific evidence arguing for a daily vitamin D supplementation with 2000 international units (IU) (50 µg) of vitamin D3 to prevent and treat vitamin D deficiency. According to data from randomized controlled trials (RCTs), such a dose may improve some health outcomes and is sufficient to raise and maintain serum 25(OH)D concentrations above 50 nmol/L (20 ng/mL) and above 75 nmol/L (30 ng/mL) in >99% and >90% of the general adult population, respectively. According to large vitamin D RCTs, there are no significant safety concerns in supplementing such a dose for several years, even in individuals with an already sufficient vitamin D status at baseline. A daily vitamin D supplementation with 2000 IU (50 µg) may be considered a simple, effective, and safe dosage to prevent and treat vitamin D deficiency in the adult general population.

Is Dietary (Food) Supplement Intake Reported in European National Nutrition Surveys?

Dietary (food) supplements (DSs) have seen a sharp increase in use and popularity in recent years. Information on DS consumption is vital for national nutrition monitoring. The objective of this study was to investigate whether DS intake was reported in the National Nutrition Surveys (NNSs) in all European countries. NNSs reporting DS use were retrieved via literature review (i.e., PubMed, Google Scholar, Scopus), scientific and organizational publications (EFSA), or open-published government and other official reports. Included were the European NNSs referring to adults, published in English, French, or German, post-2000. Out of the 53 European countries, 30 recorded DS intake. Among them, related findings on the percentage of DS intake were published in 21 cases, 5 of them written in the local language. DS use varied by nation, with Finland and Denmark having the greatest (over 50%) and Italy having the lowest percentage (5%). In terms of comprehensive reported data on DS consumption in Europe and the investigation of the contribution of DSs to total nutrient intake, there is a need for improvement. Common DS categories should be defined upon agreement among the involved scientific parties to allow for comparable data and estimations between surveys.

Vitamin D Levels Are Associated with Cardiovascular Disease Events but Not with Cardiovascular Disease or Overall Mortality: A Prospective Population-Based Study

(1) Background: A recent review concluded that there was no strong evidence for beneficial vitamin D effects on cardiovascular disease (CVD) risk, but whether individuals with vitamin D deficiency have a higher risk of CVD should be further studied. (2) Aims: We assessed the association between vitamin D levels and CVD events, CVD mortality, and overall mortality in a prospective population-based study in Lausanne, Switzerland. (3) Methods: A total of 5684 participants (53.6% women, 52.5 ± 10.7 years) were followed for a median of 14.4 years [interquartile range: 10.7-16.6]. Vitamin D blood levels were categorized as normal (≥75 nmol/L or 30 ng/mL), insufficient (50-74 nmol/L or 21-29 ng/mL), and deficient (<50 nmol/L or 20 ng/mL). (4) Results: In total, 568 cardiovascular events, 114 cardiovascular deaths, and 679 deaths occurred during follow-up. After multivariate analysis, vitamin D levels were negatively associated with CVD events: hazard ratio and (95% confidence interval) for a 10 nmol/L increase: 0.96 (0.92-0.99). However, no association was found for CVD [0.93 (0.84-1.04)] and overall mortality [0.98 (0.94-1.02)]. No associations were found between vitamin D categories and CVD events, 0.93 (0.71-1.22) and 1.14 (0.87-1.49); CVD deaths, 0.78 (0.41-1.50) and 1.10 (0.57-2.12); and overall mortality, 1.10 (0.82-1.48); and 1.17 (0.87-1.58) for insufficiency and deficiency, respectively. After excluding participants taking vitamin D supplements, similar results were obtained. (5) Conclusion: In this prospective population-based study, vitamin D levels were inversely associated with CVD events but not with CVD or overall mortality.

About the associations of vitamin D deficiency and biomarkers of systemic inflammatory response with all-cause and cause-specific mortality in a general population sample of almost 400,000 UK Biobank participants

It is unknown whether the well-known association between vitamin D deficiency and mortality could be explained by the immune system modulating effects of vitamin D, which may protect from a systemic inflammatory response (SIR) to adverse health conditions. This study aims to investigate the interrelationships of vitamin D deficiency, biomarkers of SIR, and mortality. We used multivariate logistic regression with adjustment for 51 covariates to assess the associations of vitamin D deficiency with disadvantageous levels of nine biomarkers of SIR in the UK Biobank cohort. Furthermore, we tested with Cox regression and mediation analysis whether biomarkers of SIR and vitamin D deficiency were independently associated with mortality. We included 397,737 participants aged 37-73 years. Vitamin D deficiency was associated with disadvantageous levels of all blood cell count-based biomarkers, but not with C-reactive protein (CRP)-based biomarkers after adjustment for body weight. Vitamin D deficiency and all biomarkers of SIR were significantly associated with all-cause mortality and mortality from cancer, cardiovascular and respiratory disease. The strength of these associations was unaltered if vitamin D deficiency and biomarkers of SIR were put in the same model. This finding was further supported by the mediation analyses. This study showed that vitamin D deficiency is associated with disadvantageous levels of blood cell count-based but not CRP-based biomarkers of SIR. Vitamin D deficiency and systemic inflammation were independently and strongly associated with mortality. The potential of clinical interventions against both vitamin D deficiency and underlying causes of systemic inflammation should be explored.

The Genetic Architecture of Vitamin D Deficiency among an Elderly Lebanese Middle Eastern Population: An Exome-Wide Association Study

The Middle East region experiences a high prevalence of vitamin D deficiency, yet most genetic studies on vitamin D have focused on European populations. Furthermore, there is a lack of research on the genomic risk factors affecting elderly people, who are more susceptible to health burdens. We investigated the genetic determinants of 25-hydroxyvitamin D concentrations in elderly Lebanese individuals (n = 199) through a whole-exome-based genome-wide association study. Novel genomic loci displaying suggestive evidence of association with 25-hydroxyvitamin D levels were identified in our study, including rs141064014 in the MGAM (p-value of 4.40 × 10^-6) and rs7036592 in PHF2 (p-value of 8.43 × 10^-6). A meta-analysis of the Lebanese data and the largest European genome-wide association study confirmed consistency replication of numerous variants, including rs2725405 in SLC38A10 (p-value of 3.73 × 10^-8). Although the polygenic risk score model derived from European populations exhibited lower performance than European estimations, it still effectively predicted vitamin D deficiency among our cohort. Our discoveries offer novel perspectives on the genetic mechanisms underlying vitamin D deficiency among elderly Middle Eastern populations, facilitating the development of personalized approaches for more effective management of vitamin D deficiency. Additionally, we demonstrated that whole-exome-based genome-wide association study is an effective method for identifying genetic components associated with phenotypes.

The Role of Vitamin D for Human Health: The Challenge of the Right Study Designs and Interpretation

Numerous observational and intervention studies have suggested adverse health effects of poor vitamin D status and health benefits of vitamin D intake [...].