**11. Renal disease**

Observational studies show that there are potential benefits to vitamin D supplementation in patients with chronic kidney disease (CKD). In a meta-analysis of some of these studies, it was determined that receiving treatment with any vitamin D derivative reduces all-cause mortality as well as CV mortality [68]. In another, more recent, meta-analysis of observational studies, it has been shown that vitamin D treatment may pose benefits toward reducing all-cause mortality and CV related mortality [69].

To further assess some of the available randomized, clinical trials for renal patients, a meta-analysis was done to test the efficacy of vitamin D supplementation in these patients. The 13 trials used for the meta-analysis showed no significant benefits for serious adverse CV events, all-cause mortality, or CV related mortality in CKD patients who supplemented with vitamin D. Unfortunately, there is a lack of patient level data relating to patients with CKD, making it difficult to draw any conclusions regarding the effects of vitamin D supplementation on CV health in this population [70].

In many of the previous studies in patients with CKD, the dosage of vitamin D has been limited in order to protect patients from developing hypercalcemia. Additionally, a lack of standardization in vitamin D formulations has made it especially difficult to compare results in different trials. Larger randomized trials with well-defined primary outcomes need to be conducted in order to further define vitamin D's effect on CVD in renal patients. In 2025, the SIMPLIFIED trial is expected to conclude and expectantly give insight into the effects of vitamin D supplementation on hard endpoints of all-cause mortality and CV related mortality in CKD patients [71, 72].

#### **12. Conclusions**

Epidemiologic, observational and laboratory evidence have implicated vitamin D deficiency in the pathogenesis and complications of CVD. This lent extensive biologic plausibility to the theory that vitamin D levels would be an effective target

**221**

**Author details**

Jeremy I. Purow1

Bronx, New York, United States

*Vitamin D and Cardiovascular Disease: The Final Chapter?*

prevention is not recommended for the general public.

book open on vitamin D for the foreseeable future.

and Seth I. Sokol2,3\*

1 Yeshiva University, New York, New York, United States

\*Address all correspondence to: seth.sokol@nychhc.org

provided the original work is properly cited.

2 Department of Medicine, Division of Cardiology, Jacobi Medical Center,

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

3 Albert Einstein College of Medicine, Bronx, New York, United States

for CVD prevention. However, like many other trials of vitamin supplementation, large randomized placebo-controlled trial data from the general population have refuted this theory. Therefore, vitamin D supplementation for the purpose of CVD

Based on the findings in the most recent clinical trials, it appears that the last chapter may have been written regarding the role of vitamin D for CVD prevention in the general population. However, many questions still remain and will likely fuel ongoing investigation and debate. Was the follow-up in these recent trials long enough? Do large trials randomizing by baseline vitamin D status need to be conducted since the mean vitamin D levels in VITAL and VIDA were both above the deficient threshold of 20 ng/mL? [9, 10]. Are there benefits to vitamin D repletion for heart failure outcomes? What is the true benefit of vitamin D repletion on CVD outcomes in the chronic kidney disease and dialysis population? These questions and others regarding both CVD and other chronic disease states will likely keep the

*DOI: http://dx.doi.org/10.5772/intechopen.90106*

**13. Future directions**

for CVD prevention. However, like many other trials of vitamin supplementation, large randomized placebo-controlled trial data from the general population have refuted this theory. Therefore, vitamin D supplementation for the purpose of CVD prevention is not recommended for the general public.
