Daily supplementation with Vitamin D, 50 mcg (2,000 IU) per day, produced a marked increase in circulating levels of interleukin 10, an important anti-inflammatory cytokine, in patients with chronic congestive heart failure.
A number of recent studies have linked vitamin D deficiency with increased risk of cardiovascular disease, and several research teams have put forward the theory that vitamin D can benefit patients with heart disease by down-regulating the inflammatory signals that lead to acute episodes. The new study, led by Stefanie Schleithoff, MD, at the University of Bonn, Germany, is the first to document beneficial cytokine changes resulting from vitamin D supplementation in people with advanced heart disease.
She and her colleagues studied 123 patients with confirmed CHF, randomized to treatment with either 50 mcg per day of vitamin D plus 500 mg calcium, or calcium alone, for nine months.
Compared with the control group, those taking the vitamin D showed a mean 43% increase in IL-10. Equally important, those on vitamin D showed no increase in circulating levels of Tumor Necrosis Factor-α, one of the major pro-inflammatory cytokines. The control group showed a mean 12% increase in TNF-α over the course of the study (Schleithoff S, et al. Am J Clin Nutrit. 2005; 83: 754–759).
Despite the changes in inflammatory cytokines, the University of Bonn team did not observe any measurable improvement in ejection fraction among the patients receiving vitamin D. However, an earlier study of CHF patients taking far lower vitamin D doses (400 IU per day) did show improvements in heart function, though no changes in cytokine profiles. Other studies have suggested that vitamin D can improve myocardial function, reduce blood pressure, and improve glucose tolerance, all of which would be beneficial for patients with CHF.
The precise role of vitamin D in the management of CHF and other forms of cardiovascular disease remains to be determined, but this study builds on an increasingly strong scientific foundation indicating that deficiencies correlate with increased risk, and supplementation can modulate important disease drivers (Schlethoff S, et al. J Amer Coll Cardiol. 2003; 41: 105–112).
In an editorial accompanying Dr. Schleithoff’s study, Drs. Reinhold Vieth and Samantha Kimball from the University of Toronto pose an even more important question: to what extent can vitamin D supplementation, as part of a comprehensive nutritional strategy, help in primary prevention of CHF?
Given an estimated 5 million people in the US with CHF, and another 14 million in Europe, this is a question well worth researching.
For more on the role of vitamin D in the prevention and treatment of a host of common disorders, join www.holisticprimarycare.net and download “Better Bones and Beyond: Vitamin D Is Key in Preventing Inflammatory and Metabolic Diseases” from our Fall 2004 edition.
