Written by Masoumeh Kheirandish, Maryam Heroabadi, Fatemeh Moltafet, Sholeh Namazi, Elham Bushehri
Introduction: Vitamin D is a fat-soluble vitamin, which is produced by the effect of ultraviolent ray in skin. Low levels of vitamin D causes vascular inflammation, endothelial dysfunction, and proliferation of smooth muscles. Several prospective studies have shown the role of vitamin D deficiency in hypertension and ischemic heart diseases and sudden death and heart failure. Considering that the results of clinical trial studies regarding the effect of vitamin D on the improvement of physical function and quality of life in patients with heart failure have not been concurred, this study aims to investigate the Effect of vitamin D on physical activity and quality of life in patients with heart failure.
Method: Patients with heart failure who were eligible for referral from cardiologists after checking inclusion and exclusion criteria and confirming entry to the study were randomly assigned to control or treatment groups using randomized blocking method. The treatment group received vitamin D 50000 weekly units and calcium carbonate 1000 mg daily for 8 weeks and the control group received placebo, which was similar to vitamin D, on a weekly basis and calcium carbonate 1000 mg daily for 8 weeks. The blood levels of vitamin D were measured in the treatment group at the end of the study. At the end of the study, six-minute walking test, physical performance and quality of life were measured in both groups.
Results: From 59 patients 40 (67.8%) were male and 19 (32.2%) were women. The mean age of the patients was 58.88 ± 10.08 with a maximum of 75 and a minimum of 39. The quality of life of patients before and after the study was not significantly different between the two groups (P > 0.05). However, in each of these groups, the life-span of life before and after study shows a significant increase. The distance traveled in the 6-minute walk test before and after the study between the two groups was not significantly different (P > 0.05). Also, the distance traveled in each of the groups did not differ significantly before and after the study (P > 0.05) and this means that the results of the 6-minute walk test did not change significantly. Physical function of patients in the two groups of treatment and control according to the international classification was divided into 4 categories. Because of the inability of group 4 to participate in the 6-minute walk test, the first three groups were selected for walking. There was no significant difference before the beginning of the study (P > 0.05). Also, physical performance of patients between the two groups did not show significant difference after the study (P > 0.05).
Conclusion: In the present study, despite the use of vitamin D in patients with heart failure, no improvement in quality of life or physical ability was observed. However, according to the findings of other studies, the effect of vitamin D has not been adequately proven, and there are contradictory results in this regard, which necessitates the need for further studies on this topic.
Keywords: Vitamin D, heart failure, quality of life, physical activity