Blood Pressure in Healthy Youngsters is modified by Vitamin-D Supplementation

Objective Our study aimed to investigate the effect of vitamin D supplementation on blood pressure in vitamin D insufficient young volunteers compared to an age matched control group with sufficient levels of vitamin D. Secondarily we aimed to evaluate the effect of vitamin D supplementation on the RAAS and sympathetic nervous system. Design Single centre, Randomised controlled Trial. of Range 2.4) mmHg (p = 0.009), diastolic BP (daytime) decreased -4.5 (2.1) mmHg (p = 0.03), norepinephrine decreased -0.80 (0.21) nmol/L, (p = 0.0002). There was no effect of vitamin D supplementation on night time systolic or diastolic BP, and no effect on angiotensinogen, renin, angiotensin (I+II), aldosterone or epinephrine. We observed that 180 days of vitamin D supplementation in normal youngsters with insufficient vitamin D significantly lowered systolic and diastolic BP during daytime. Vitamin D supplementation also significantly lowered circulating norepinephrine. Nothing happened in the control group with normal vitamin D. Hence, it is tempting to conclude that vitamin D acts on BP through SNS as no changes were observed in the RAAS.