Association between serum vitamin D levels and venous thromboembolism (VTE): A systematic review and meta-analysis of observational studies

Causality assessment of circulating Vitamin D level on venous thromboembolism: A Mendelian randomization study

BACKGROUND AND AIMS

The associations of vitamin D level with venous thromboembolism (VTE) reported in observational studies, whereas these causal associations were uncertain in European population. Therefore, we used Mendelian randomization (MR) method to explore the causal associations between 25-hydroxyvitamin D (25(OH)D) concentrations and the risk of VTE and its subtypes [including deep vein thrombosis (DVT) and pulmonary embolism (PE)].

METHODS AND RESULTS

We used three kinds of genetic instruments to proxy the exposure of 25(OH)D, including genetic variants significantly associated with 25(OH)D, expression quantitative trait loci of 25(OH)D target genes, and genetic variants within or nearby 25(OH)D target genes. MR analyses did not provide any evidence for the associations of 25(OH)D levels with VTE and its subtypes (p > 0.05). The summary-data-based MR (SMR) analyses indicated that elevated expression of VDR was associated with decreased risk of VTE (OR = 0.81; 95% CI, 0.65-0.998; p = 0.047) and PE (OR = 0.67; 95% CI, 0.50-0.91; p = 0.011), and expression of AMDHD1 was associated with PE (OR = 0.93; 95% CI, 0.88-0.99; p = 0.027). MR analysis provided a significant causal effect of 25(OH)D level mediated by gene AMDHD1 on PE risk (OR = 0.09; 95% CI, 0.01-0.60; p = 0.012).

CONCLUSION

Our MR analysis did not support causal association of 25(OH)D level with the risk of VTE and its subtypes. In addition, the expression of VDR and AMDHD1 involved in vitamin D metabolism showed a strong association with VTE or PE and might represent targets for these conditions.

Is Circulating Vitamin D Status Associated with the Risk of Venous Thromboembolism? A Meta-Analysis of Observational Studies

BACKGROUND

Although vitamin D is antithrombotic, associations between serum vitamin D status and the risk of venous thromboembolism (VTE) remain inconsistent.

METHODS

We searched the EMBASE, MEDLINE, Cochrane Library, and Google Scholar databases from inception to June 2022 to identify observational studies examining associations between vitamin D status and VTE risk in adults. The primary outcome presented as odds ratio (OR) or hazard ratio (HR) was the association of vitamin D levels with the risk of VTE. Secondary outcomes included the impacts of vitamin D status (i.e., deficiency or insufficiency), study design, and the presence of neurological diseases on the associations.

RESULTS

Pooled evidence from a meta-analysis of sixteen observational studies, including 47648 individuals published from 2013 to 2021, revealed a negative relationship between vitamin D levels and the risk of VTE either based on OR (1.74, 95% confidence interval (CI): 1.37 to 2.20, p < 0.00001; I² = 31%, 14 studies, 16074 individuals) or HR (1.25, 95% CI: 1.07 to 1.46, p = 0.006; I² = 0%, 3 studies, 37,564 individuals). This association remained significant in subgroup analyses of the study design and in the presence of neurological diseases. Compared to individuals with normal vitamin D status, an increased risk of VTE was noted in those with vitamin D deficiency (OR = 2.03, 95% CI: 1.33 to 3.11) but not with vitamin D insufficiency.

CONCLUSIONS

This meta-analysis demonstrated a negative association between serum vitamin D status and the risk of VTE. Further studies are required to investigate the potential beneficial effect of vitamin D supplementation on the long-term risk of VTE.

Vitamin D Deficiency is Associated With Increased Plasminogen Activator Inhibitor 1/Plasminogen Activator Inhibitor 2 Ratio in Pregnancy

BACKGROUND

Vitamin D deficiency has recently been suggested as an independent risk factor for thrombosis. Notably, vitamin D deficiency is common in pregnant populations, whom already have an increased thrombotic risk. However, pregnant women are commonly excluded from studies investigating the hemostatic system, and knowledge on the impact of vitamin D on hemostasis in pregnancy is therefore limited.

METHODS

A cross-sectional study comparing the hemostatic profile of pregnant women (gestational week 12.9 ± 0.7) with vitamin D deficiency (≤50 nmol/L) (n = 70) and high adequate vitamin D status (≥100 nmol/L) (n = 59).

RESULTS

Vitamin D deficient women displayed increased plasminogen activator inhibitor 1 levels and an increased plasminogen activator inhibitor 1/plasminogen activator inhibitor 2 ratio, even after adjusting for factors with potential influence on hemostasis (body mass index, smoking and use of fish oil supplements).

CONCLUSIONS

Vitamin D deficiency is associated with increased plasminogen activator inhibitor 1/plasminogen activator inhibitor 2 ratio in pregnant women. As an increased plasminogen activator inhibitor 1/plasminogen activator inhibitor 2 ratio with high plasminogen activator inhibitor 1 levels may increase thrombotic risk and is associated with the development of pregnancy complications, further research is needed to determine the optimal vitamin D supplementation in pregnancy.

Is Vitamin D Deficiency Prothrombotic? A Systematic Review

Observational studies indicate a relationship between vitamin D deficiency and an increased risk of venous and arterial thrombotic events, but the underlying mechanisms behind this association are uncertain. This systematic review explores if there is an association between decreased vitamin D levels and a prothrombotic profile. The systematic literature search initially identified 3,214 studies (published until December 21, 2021) investigating the relationship between vitamin D and numerous hemostatic parameters. After the screening process, 18 observational and intervention studies fulfilled the inclusion criteria and were included in this systematic review. Parameters of primary hemostasis, secondary hemostasis, and fibrinolysis were investigated in six, thirteen, and fifteen of these studies, respectively. Most of the eligible studies did not identify significant associations between decreased vitamin D levels and hemostatic parameters. Some conflicting results were found between decreased vitamin D levels and thrombin generation parameters and the tissue factor pathway inhibitor. Conflicting results were also found between decreased vitamin D levels and fibrinolytic parameters, although the evidence may point toward weak associations with some regulators of fibrinolysis, mostly decreased tissue type plasminogen activator. Overall, our systematic review did not identify any definitive link between vitamin D deficiency and a prothrombotic profile, which might otherwise help explain the observed association between vitamin D deficiency and increased risk of thrombotic events. Moreover, there is no clinical evidence to confirm or refute a possible antithrombotic effect of vitamin D. Larger high-quality randomized controlled trials are needed to better elucidate the link between vitamin D deficiency and a prothrombotic risk profile.

The Role of Vitamin D in the Relationship Between Gender and Deep Vein Thrombosis Among Stroke Patients

Introduction: Accumulating evidence had demonstrated that females had a higher risk of deep vein thrombosis (DVT) than males, but the mechanism was still unknown. Vitamin D was found to play an essential role in DVT, and gender may influence the serum vitamin D levels. This study aimed to explore whether vitamin D played a role in the gender difference in DVT.

Materials and Methods: A total of 444 patients with acute stroke were recruited, which were divided into the DVT group (n = 222) and the non-DVT group (n = 222). Serum vitamin D levels were measured after admission and were split into three categories, including deficiency (<50 nmol/L), insufficiency (52.5–72.5 nmol/L), and sufficiency (more than 75 nmol/L). Hierarchical regression analysis was adopted to analyze the relationship between gender and DVT, controlling the confounding factors.

Results: Females showed a higher proportion of DVT than males (60.7 vs. 42.5%, p < 0.001), and lower serum vitamin D levels than males (53.44 ± 16.45 vs. 69.43 ± 23.14, p < 0.001). Moreover, serum vitamin D levels were lower in the DVT group than in the non-DVT group (59.44 ± 19.61 vs. 66.24 ± 23.86, p < 0.001). Besides, the DVT group showed a lower proportion of vitamin D sufficiency than the non-DVT group (21.2 vs. 32.9%, p < 0.05). Hierarchical regression analysis showed that females had 2.083-fold (p < 0.001, unadjusted model) and 1.413-fold (p = 0.155, adjusted model) risk to develop DVT. In addition, the sufficiency status of vitamin D showed an independent protective effect on DVT (unadjusted model OR, 0.504, p = 0.004; adjusted model OR, 0.686, p = 0.011).

Conclusion: Females had a higher risk of DVT than males, and vitamin D may play an essential role in this relationship. Further studies are needed to explore whether vitamin D supplementation could reduce DVT risk in stroke patients, especially females.

Notable Developments for Vitamin D Amid the COVID-19 Pandemic, but Caution Warranted Overall: A Narrative Review

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel contagion that has infected over 113 million people worldwide. It is responsible for the coronavirus disease (COVID-19), which has cost the lives of 2.5 million people. Ergo, the global scientific community has been scrambling to repurpose or develop therapeutics to treat COVID-19. Dietary supplements and nutraceuticals are among those under consideration due to the link between nutritional status and patient outcomes. Overall, poor vitamin D status seems to be associated with an increased risk of COVID-19. Severely ill COVID-19 patients appear to be deficient or have suboptimal levels of serum 25-hydroxyvitamin D, a measure of vitamin D status. Consequently, vitamin D is now the subject of several prophylactic and therapeutic clinical trials. In this review, the general status of nutraceuticals and dietary supplements amid the pandemic is appraised, with a particular focus on vitamin D. Consumers should be aware of misinformation and unsubstantiated promises for products marketed for COVID-19 protection. However, maintaining a healthy diet and lifestyle will likely maintain health including optimum immune function that may affect patient outcomes. Those who are deficient in key nutrients such as vitamin D should consider lifestyle changes and potentially supplementation in consultation with their physician and/or registered dieticians.

Single high-dose vitamin D3 injection and clinical outcomes in brain tumor resection: A randomized, controlled clinical trial

BACKGROUND & AIMS

Vitamin D is known as a neuroprotective hormone with anti-inflammatory and immune-modulatory properties. We evaluated the effect of vitamin D3 injection on vitamin D status and clinical outcomes in patients with low serum levels of 25-hydroxyvitamin D [25(OH)D] undergoing craniotomy for brain tumor resection.

METHODS

Patients with benign brain tumors and serum 25(OH)D levels ≤20 ng/mL were randomized to two groups with an equal number of subjects. The study group (n = 30) received intramuscular injection of 300,000 IU vitamin D3 prior to surgery. The control group (n = 30) was left without intervention, and both groups underwent routine therapies.

RESULTS

On day 5 after craniotomy, the serum 25(OH)D levels increased significantly in the study group (P= <0.001). The length of ICU and hospital stay was significantly lower in the study group compared to the control group (P = 0.01 and P = 0.008, respectively). It was true when the age, tumor size, tumor type, Karnofsky Performance Scale (KPS) score, and calcium and albumin levels at baseline entered the logistic regression model (OR = 0.17 (95%CI = 0.04-0.72, P = 0.01), and OR = 0.19 (95%CI = 0.04-0.82, P = 0.02), respectively). With and without the application of logistic regression analysis, there was no significant difference in perioperative complications.

CONCLUSIONS

Intramuscular injection of 300,000 IU of vitamin D3 in patients with low serum levels of 25(OH)D undergoing craniotomy, could rise safely the serum 25(OH)D level. This intervention, significantly reduced the length of ICU stay and hospitalization.

REGISTERED UNDER

Clinicaltrials.gov.identifier no: NCT03248544. Date: 8/14/2017.