Vitamin D Status and CHF.
The heart, our hardest working organ, is a pump made of muscle. It is the most efficient muscle in the body. Generating its own electrical impulses, the heart beats continuously without rest for as long as we live. Congestive heart failure is a health condition in which the pumping ability of the heart becomes weak. The heart just doesn't have the oomph it used to. It no longer beats with enough force to properly circulate blood throughout the body. When the heart loses pumping strength, excess sodium and water may accumulate in the tissues, causing "congestion" of fluid that puts an even greater burden on the circulatory system. People sometimes have signs of congestive heart failure without any symptoms of congestion, however, so doctors now prefer the term "heart failure." Heart failure can be caused by a variety of cardiac disorders, so it is actually a clinical syndrome rather than a specific disease.
Doctors use the term "ejection fraction" to describe the amount of blood propelled out from the heart to the body. The heart normally ejects about 60% of its blood volume in one beat. With heart failure it may pump as little as 20 to 30 percent. The entire circulatory system becomes sluggish, putting more strain on the weak heart. With the circulatory system overloaded like this, the volume of blood returning to the heart through the veins increases. A normal heart responds by increasing the force of its contractions. In heart failure, the heart is simply not up to the task.
Recently published, a new study examined the potential role of vitamin D deficiency in congestive heart failure. This study recruited 20 individuals under the age of 50 years, and 34 over the age of 50, all with New York Heart Association classes. A control group was also gathered. Using blood samples from these patients, vitamin D status, parameters of calcium metabolism, and a predictor of CHF called NT-proANP were measured. The results showed that the CHF group had higher serum levels of NT-proANP and lower levels of vitamin D when compared to the control group. The authors of this study determined that, "The low vitamin D status can explain alterations in mineral metabolism as well as myocardial dysfunction in the CHF patients, and it may therefore be a contributing factor in the pathogenesis of CHF."1
1. Zittermann A, et al. Low vitamin D status: a contributing factor in the pathogenesis of congestive heart failure? J Am Coll Cardiol. Jan 2003;41(1):105-112.