Two recent studies find no benefit to the heart from supplementing with vitamin D.
The most recent:
Vitamin D Therapy and Cardiac Structure and Function in Patients With Chronic Kidney Disease, The PRIMO Randomized Controlled Trial, Journal of the American Medical Association, February 2012
Found a lack of improvement in heart structure and function in patients taking the active vitamin D compound, paricalcitol. The trial included 227 patients with chronic kidney disease. It lasted 48 weeks.
"Conclusion: Forty-eight week therapy with paricalcitol did not alter left ventricular mass index or improve certain measures of diastolic dysfunction in patients with chronic kidney disease."There were some negative effects from the vitamin D supplementation:
- Those taking vitamin D experienced more frequent episodes of hypercalcemia (high levels of calcium in the blood).
- Those taking vitamin D showed increased serum creatinine levels and decreased glomerular filtration rate (GFR, a measure of kidney function estimated from creatinine levels).
A Prospective Randomized Controlled Trial of the Effects of Vitamin D Supplementation on Cardiovascular Disease Risk, November 2011, Presentation at American Heart Association 2011 Scientific Sessions
Found vitamin D supplementation (2500 IU vitamin D3) for four months had no significant effect on blood vessel function in postmenopausal women.
"Conclusions: Vitamin D supplementation did not improve endothelial function, vascular stiffness, or inflammation in healthy post-menopausal women. This study does not support the use of VitD supplementation to reduce cardiovascular disease risk."Both of these studies were randomized, placebo-controlled trials, not epidemiological studies. Randomized trials are usually less biased and show a more clear picture of the effect of the intervention.
