New research out of Iran has found that vitamin D supplementation may improve the severity of congestive heart failure.
Heart failure (HF) affects 15 million people worldwide. It is characterized by the heart’s inability to sufficiently pump blood to meet the blood flow requirements of the body. This causes a diminished quality of life due to frailty, muscle weakness and shortness of breath. It also increases your risk of dying significantly.
Researchers from the International Heart Institute of Montana in combination with Saint Patrick Hospital, who are looking for funding to complete their own heart failure trial, gave a good background on the research to date between vitamin D and HF in this blog here. In short, vitamin D deficiency is common in HF. Researchers are wondering if vitamin D deficiency is making HF more severe, and if vitamin D supplementation might help slow disease progression of HF. Finally, researchers are curious if vitamin D supplementation might improve overall quality of life.
In this present study published recently in the journal Congestive Heart Failure, researchers studied 100 patients with HF in a prospective open-label trial, using vitamin D supplementation as an intervention. The patients were consecutively enrolled into the study as they presented to the Rajei Cardiovascular, Medical and Research Center. All patients had been receiving optimal medical treatment of diuretics and neurohormonal blockers in accordance to guidelines on HF management. The average age of the enrollees was 45 years.
Upon enrollment, researchers measured vitamin D levels. Ninety-four patients had levels less than 30 ng/ml. All of these patients were placed on vitamin D supplementation. They received 50,000 IU of vitamin D3 each week for 8 weeks and then 50,000 IU/month for the next 2 months thereafter.
The researchers wanted to know, did these patients’ cardiac, physical performance and biochemical characteristics improve at all after supplementation?
Here is what they found:
- Vitamin D levels rose from a mean level of 5 ng/ml at baseline to 21.8 ng/ml.
- Mean NYHA functional class in the study population improved significantly (P<.001). The NYHA stands for New York Heart Association, and they have a class rating system to describe severity of HF from I (no HF symptoms) to IV (symptoms at rest). Investigators examined patients at rest, dressing, walking and climbing stairs and assessed NYHA scores at baseline and at the end of the study. Over the course of the study, NYHA scores improved.
- Pro–brain natriuretic peptide (proBNP) levels decreased by 827.3 ng/ml (P<.001). proBNP are produced within the heart and released into circulation. Patients with HF have elevated proBNP, so proBNP is used in part to diagnose HF.
- High-sensitivity C-reactive protein (hs-CRP) declined (P<.001). hs-CRP is a marker of inflammation in HF.
The researchers concluded,
“The results of our study indicate that an appropriate strategy of vitamin D supplementation decreases the severity of HF, reflected in the reduction of serum proBNP. We also demonstrated that vitamin D causes a pronounced improvement in physical capacity of patients. Moreover, vitamin D was able to suppress the concentration of hs-CRP. Our data provide valuable evidence for the efficacy of vitamin D supplementation in the optimal management of HF.”
One limitation is that the study, while it did implement vitamin D supplementation as an intervention, is that it wasn’t a randomized placebo-controlled trial. So, the researchers didn’t have a control group to compare to. We can’t rule out possible bias in their findings, and we can’t say for sure if vitamin D was causative in improving HF severity. The study also had a small number of enrollees and didn’t raise vitamin D levels by all that much (could have used a bigger vitamin D dose).
One strength of the study was how low the baseline vitamin D levels were. In consequence, the researchers may have really benefited in their ability to greatly improve HF markers that severe deficiency may exacerbate, a luxury not all studies have. For example, some studies are only able to examine a population that is only mildly deficient in vitamin D, which in turn only leave slight room for improvement in endpoints.
While more research is needed and underway, this study does provide some initial evidence that vitamin D supplementation may be an important and vital complimentary treatment for those with HF.
Amin, A., Minaee, S., Chitsazan, M., Naderi, N., Taghavi, S., & Ardeshiri, M. (2013). Can vitamin D supplementation improve the severity of congestive heart failure? Congestive heart failure (Greenwich, Conn.), 19(4), E22–8. doi:10.1111/chf.12026