Effects of Vitamin D Supplementation on Central Hemodynamic Parameters and Autonomic Nervous System in Obese or Overweight Individuals

Abstract

Background

Previous studies have been inconsistent in demonstrating beneficial cardiovascular effects of vitamin D supplementation.

Objective

To evaluate the effects of vitamin D3 supplementation on central hemodynamic parameters and autonomic activity in obese/overweight individuals with low vitamin D levels (<30ng/dl).

Methods

Adults 40-65 years old with body mass index ≥25<40 kg/m² were enrolled in this prospective, randomized, double-blind clinical trial (NCT 05689632). Central hemodynamics was assessed using the oscillometric method (Mobil-O-Graph^®), and heart rate variability using a Polar heart rate monitor (Kubios^® software). Patients (n=53) received a placebo in the control group (CO, n=25) or vitamin D3 (VD, n=28) 7000 IU/day, and were evaluated before (W0) and after 8 weeks (W8) with a significance level of 0.05.

Results

The groups were homogeneous regarding age (51±6 vs 52±6 years, p=0.509) and vitamin D levels (22.8±4.9 vs 21.7±4.5ng/ml, p=0.590). At W8, the VD group had significantly higher levels of vitamin D (22.5 vs 35.6ng/ml, p0.05). VD group showed an increase in the parasympathetic nervous system index (PNSi) (-0.64±0.94 vs -0.16±1.10, p=0.028) and the R-R interval (866±138 vs 924±161 ms, p= 0.026).

Conclusion

In this sample, eight weeks of daily vitamin D supplementation resulted in an improvement in blood pressure levels and autonomic balance.