Written by Susan Sweeny Johnson, PhD, Biochem. 93 patients with congestive heart failure, who supplemented with 2000 IU of Vitamin D per day for 9 months, had decreased inflammation but there was no effect on heart function or longevity.
Congestive heart failure (CHF) results from strain put on the heart by diseases such as high blood pressure, diabetes or coronary artery disease. The heart muscle is weakened to the point where it cannot deliver adequate blood or oxygen to the body. Only 35-50% of CHF patients survive five years after diagnosis.(1)
Much of the latest evidence suggests that inflammation contributes to the breakdown of the heart leading to CHF. Inflammation is induced or suppressed by cytokines (small immunoregulatory proteins) which are in turn regulated by the vitamin D hormone, calcitrol. (2,3,4) Since CHF patients have very low levels of vitamin D metabolites and calcitrol in their blood, (5) these researchers decided to look at the effect of vitamin D supplementation on CHF patient’s heart health and blood levels of specific cytokines.
In this study, 123 male and female patients with middle stage CHF were given 2000 IUs of vitamin D per day or a placebo. This is the highest dosage of vitamin D considered safe. All participants additionally received 500 mg calcium per day to ensure sufficient daily intake. Patients were assessed at the beginning of the study and after nine months.
Twenty-five patients dropped out of the study because their health declined so dramatically. Thirteen of these patients died before a 15 month follow up – half in the placebo group and half in the vitamin D group. All of the patients who dropped out had lower concentrations of vitamin D metabolite in their blood and poorer heart function at the beginning of the study than the ones who remained in the study.
The ninety-three patients that completed the study showed significant differences in the level of inflammation cytokines. Tumor necrosis factor (TNFalpha) which promotes inflammation increased in the placebo group but decreased slightly in the vitamin D group. Interleukin-10, an anti-inflammatory cytokine, increased in the vitamin D group but decreased in the placebo group. Heart function improved slightly in both groups. Of course, serum concentrations of vitamin D metabolite were much higher in the vitamin D group.
Therefore, vitamin D supplementation at high doses (2000 IU per day) apparently reduced inflammation in congestive heart failure patients but had no effect on heart function or longevity after a short trial period (9 months). Taking vitamin D supplements may be one way to slow heart damage caused by high blood pressure, diabetes or coronary artery disease.
Source: Schleithoff, Stefanie S., et al. “Vitamin D supplementation improves cytokine profiles in patients with congestive heart failure: a double-blind, randomized, placebo-controlled trial.” The American journal of clinical nutrition 83.4 (2006): 754-759.
© 2006 American Society for Nutrition
Posted July 25, 2008.
References:
- Levy D, et al. Long-term trends in the incidence of and survival with heart failure. N Engl J Med 2002;347:1397-402.
- Rauchhaus M, et al. Plasma cytokine parameters and mortality in patients with chronic heart failure. Circulation 2000;102:3060-7.
- Swedberg K, et al. Effects of enalapril and neuroendocrine activation on prognosis in severe congestive heart failure. Consensus Trial Study Group. Am J Cardiol 1990;66: 40D-4D.
- Zhu Y, et al. Calcium and 1alpha,25-dihydroxyvitamin D3 target the TNF-alpha pathway to suppress experimental inflammatory bowel disease. Eur J Immunol 2005;35:217-24.
- Muller K, et al. 1.25-Dihydroxyvitamin D3inhibits cytokine production by human blood monocytes at the post-transcriptional level. Cytokine 1992;4:506-12.
