title: The Effect of Short Term Vitamin D Supplementation on the Inflammatory and Oxidative Mediators of Arterial Stiffness.
abstract: BACKGROUND
  Vitamin D deficiency has been implicated as a potential risk factor for cardiovascular disease. The high rate of vitamin D deficiency (<30 ng/ml) exhibited by African Americans may account for some of the excess prevalence of cardiovascular morbidity and mortality in this vulnerable US population. Vitamin D supplementation may reduce the risk of cardiovascular disease by ameliorating the onset and progression of arterial stiffness, a strong predictor of cardiovascular mortality, usually assessed by pulse wave velocity and augmentation index. Very few prospective studies have evaluated the effect of vitamin D supplementation on the inflammatory and oxidative stress mediators of arterial stiffness.
  
  
  METHODS
  In a double blind randomized placebo controlled study we evaluated the effect of a monthly dose of 100,000IU of vitamin D3 for three months on the level of serum 25(OH)D, intact parathyroid hormone (PTH), urinary isoprostane, adipocyte cytokine expression and arterial stiffness among 130 overweight and obese (BMI > 25) African Americans with elevated blood pressure (130 - 150/85 - 100 mmHg) and low serum vitamin D level (10 - 25 ng/ml).
  
  
  RESULTS
  There was a significant increase in the serum 25(OH)D levels to a mean level of 34.5 ng/ml (SD = 7.1) with the intervention (p < 0.001). The increase in 25(OH)D levels was associated with a significant decrease in the serum level of intact PTH (p = 0.02), mean urinary isoprostane (p = 0.02) and adipocyte cytokine expression. Although the increase in the 25(OH)D levels was not associated with any significant change in the Pulse Wave Velocity (PWV) in the overall study sample, it was associated with a significant decrease in the augmentation index among the participants with the highest tertile of urinary isoprostane (p = 0.007).
  
  
  CONCLUSIONS
  We concluded that vitamin D supplementation increased serum 25(OH)D levels, decreased intact PTH level and the levels of select inflammatory and oxidative stress mediators of arterial stiffness. Longer term prospective studies are warranted to evaluate the effect of high dose vitamin D supplementation on arterial stiffness.
authors.affiliation: Charles R. Drew University, Los Angeles, USA.
authors.forename: David
authors.initials: D
authors.lastname: Martins
authors.affiliation: Morehouse School of Medicine, Atlanta, USA.
authors.forename: Yuan-Xiang
authors.initials: YX
authors.lastname: Meng
authors.affiliation: Charles R. Drew University, Los Angeles, USA.
authors.forename: Naureen
authors.initials: N
authors.lastname: Tareen
authors.affiliation: Charles R. Drew University, Los Angeles, USA.
authors.forename: Jorge
authors.initials: J
authors.lastname: Artaza
authors.affiliation: Jackson State University, Jackson, USA.
authors.forename: Jae Eun
authors.initials: JE
authors.lastname: Lee
authors.affiliation: Charles R. Drew University, Los Angeles, USA.
authors.forename: Caroline
authors.initials: C
authors.lastname: Farodolu
authors.affiliation: National Heart, Lung, and Blood Institute, Bethesda, USA.
authors.forename: Gary
authors.initials: G
authors.lastname: Gibbons
authors.affiliation: University of California Los Angeles, Los Angeles, USA.
authors.forename: Keith
authors.initials: K
authors.lastname: Norris
keywords: Hypovitaminosis D; Overweight; Vitamin D