Is Vitamin D Supplementation an Effective Treatment for Hypertension?

Effect of vitamin B2, vitamin C, vitamin D, vitamin E and folic acid in adults with essential hypertension: a systematic review and network meta-analysis

OBJECTIVES

The objective of the current study is to compare the treatment effects of different vitamins on essential hypertension to provide an initial basis for developing evidence-based practices.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Five electronic databases (PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov) were searched from their inception to 25 September 2023.

OUTCOMES

The primary outcomes were the difference between the intervention group and the control group in changes in office systolic blood pressure (SBP) and office diastolic blood pressure (DBP) from baseline. The secondary outcomes were the difference between the intervention group and the control group in changes in 24-hour mean ambulatory systolic blood pressure (24 hours SBP), 24-hour mean ambulatory diastolic blood pressure (24 hours DBP) and heart rate (HR) from baseline.

RESULTS

A total of 23 studies comparing five vitamins (vitamin B2, vitamin C, vitamin D, vitamin E, folic acid) and involving 2218 participants were included. The included trials were all vitamin versus placebo, so the network was star-shaped. Among the five vitamins, only vitamin E was significantly more effective at reducing SBP (mean difference: -14.14 mm Hg, 95% credible intervals: -27.62 to -0.88) than placebo. In addition, no evidence was found that any of the five vitamins influenced DBP, 24 hours SBP, 24 hours DBP, or HR. The dose of vitamins, geographical region and percentage of males (only SBP) might be sources of heterogeneity. Sensitivity and subgroup analysis revealed that the effect of vitamin intervention on blood pressure varies according to different doses of vitamins.

CONCLUSIONS

According to the results, vitamin E might be an effective measure to reduce SBP, but more research is needed to validate this finding.

PROSPERO REGISTRATION NUMBER

CRD42022352332.

The Role of Vitamin D in Health and Disease: A Narrative Review on the Mechanisms Linking Vitamin D with Disease and the Effects of Supplementation

Vitamin D insufficiency or deficiency (VDD) is a very prevalent condition in the general population. Vitamin D is necessary for optimal bone mineralization, but apart from the bone effects, preclinical and observational studies have suggested that vitamin D may have pleiotropic actions, whereas VDD has been linked to several diseases and higher all-cause mortality. Thus, supplementing vitamin D has been considered a safe and inexpensive approach to generate better health outcomes-and especially so in frail populations. Whereas it is generally accepted that prescribing of vitamin D in VDD subjects has demonstrable health benefits, most randomized clinical trials, although with design constraints, assessing the effects of vitamin D supplementation on a variety of diseases have failed to demonstrate any positive effects of vitamin D supplementation. In this narrative review, we first describe mechanisms through which vitamin D may exert an important role in the pathophysiology of the discussed disorder, and then provide studies that have addressed the impact of VDD and of vitamin D supplementation on each disorder, focusing especially on randomized clinical trials and meta-analyses. Despite there already being vast literature on the pleiotropic actions of vitamin D, future research approaches that consider and circumvent the inherent difficulties in studying the effects of vitamin D supplementation on health outcomes are needed to assess the potential beneficial effects of vitamin D. The evaluation of the whole vitamin D endocrine system, rather than only of 25-hydroxyvitamin D levels before and after treatment, use of adequate and physiologic vitamin D dosing, grouping based on the achieved vitamin D levels rather than the amount of vitamin D supplementation subjects may receive, and sufficiently long follow-up are some of the aspects that need to be carefully considered in future studies.

The importance of Vitamin-D and Neutrophil-Lymphocyte Ratio for Alzheimer's Disease

Objective

Ischemia and inflammation play a role in the pathophysiology of Alzheimer's disease (AD). Plasma neutrophil-lymphocyte ratio (NLR), and 25- hydroxyvitamin D (vitamin D) were used as a biomarker for inflammation and atherosclerosis. The present study aimed to investigate a link between NLR, vitamin D and ischemia in AD.

Methods

The subjects with AD and control groups were enrolled to this retrospective study between 2017-2022 at Cukurova University Hospital. The cognitive assessment (MMSE), and blood tests (NLR, vitamin D) were collected from all subjects. In first part of the study, AD (n:132) and the control group (n:38) were compared. In second part of the study, magnetic resonance imaging (MRI) was used for evaluating ischemic lesions with scoring method of Fazekas. The control group (n:38) and AD subjects with mild ischemic lesions (Fazekas-1 and Fazekas-2) (n:64) were excluded. AD subjects with severe ischemic lesions (Fazekas-3) (n:34) and without ischemic lesions (Fazekas-0) (n:34) were compared again. SPSS 20.0 was used for all analyses. The threshold for statistical significance was set at 0.05.

Results

In the first part of the study, 132 AD patients (69 female and 63 male; mean age 70.83±9.35 (49-87) and age-matched 38 controls were compared. The mean NLR in AD [2.96±2.46 (1.17-19.43)] was higher than the control group [1.9±0.66 (0.9-3.56)] (p=0.005). In the second part of the study, the mean Vitamin D of Fazekas-3 AD group [16.15±9.64 (4.7-35)] was lower than Fazekas-0 AD group [16.27±6.81(4.6-29.7)] (p=0.024).

Conclusion

NLR was higher in AD while there was no difference between the Fazekas-0 and Fazekas-3 AD groups. Vitamin D was lower in the Fazekas-3 AD group. These data suggested that NLR increased independently of ischemia in AD. Also vitamin D deficiency could trigger ischemia in AD.