Vitamin D ameliorates systolic but not diastolic blood pressure in patients with type 2 diabetes: Results from a meta-analysis of randomized controlled trials

Int J Vitam Nutr Res. 2018 Feb;88(1-2):90-99. doi: 10.1024/0300-9831/a000291. Epub 2019 Apr 30.


Inconsistent findings have been reported regarding the effects of vitamin D on blood pressure in patients with type 2 diabetes (T2D). This study aimed to evaluate the subject through a meta-analysis. A computerized literature search on five databases was performed and randomized controlled trials (RCTs) published until March 2016 were identified. The eligibility criteria for articles to be selected were parallel-group RCTs in which consumption of a kind of vitamin D was compared with placebo in patients with T2D. Un-standardized mean difference and its corresponding 95 % confidence interval (CI) was calculated from the effect sizes by using random effects model. Studies comparing intervention group (received vitamin D) with control group (received placebo) were enrolled in meta-analysis. Meta-analysis on 26 studies with 1789 type 2 diabetic subjects showed that vitamin D significantly reduced systolic blood pressure (SBP; -0.97 mmHg, 95 % CI: -1.94, -0.001, P = 0.050), but not diastolic blood pressure (DBP; -0.10 mmHg, 95 % CI: -0.22, 0.02, P = 0.087). Subgroup analyses showed that administration of vitamin D in patients with baseline serum 25-hydroxy vitamin D < 50 nmol/l and baseline SBP < 140 mmHg significantly reduced SBP. Moreover, the patients who received vitamin D without Ca co-supplementation showed significant reduction in SBP. Vitamin D doses (≤ 2000 or > 2000 IU/day) and method of vitamin D application (Supplementation or food fortification) did not affect the blood pressure. This study demonstrated that vitamin D improved SBP in type 2 diabetic patients. Therefore, this vitamin can be considered as an adjuvant therapy in these patients.

Keywords: Vitamin D; blood pressure; meta-analysis.; type 2 diabetes.

Publication types

  • Meta-Analysis

MeSH terms

  • Diabetes Mellitus, Type 2*
  • Humans
  • Hypertension*
  • Randomized Controlled Trials as Topic
  • Vitamin D / chemistry
  • Vitamin D / metabolism*
  • Vitamins / chemistry
  • Vitamins / metabolism*


  • Vitamins
  • Vitamin D