Previous studies have shown high proportions of vitamin D deficiency among elderly in Denmark. Vitamin D is important for muscular function. The investigators intend to examine if it is possible to improve cardiovascular function in patients with heart failure and vitamin D deficiency by supplementation with vitamin D.
Heart failure (HF) is a major course of morbidity and mortality. The prevalence in the Danish population is 1-2% and for age 50 -75 years: 2-3% (1) . It has been estimated that there are currently 6.5 million HF patients in Europe and 5 million in the USA (2) . Lack of vitamin D has been linked to heart disease including ischemic heart disease, heart failure, and hypertension.(3) Vitamin D deficiency is prevalent in the elderly population. Calcium absorption, bone mineralization and muscle function may be impaired. Vitamin D receptors have also been demonstrated in skeletal as well as cardiac muscle(4) . Vitamin D and Parathyroid Hormone (PTH) are closely linked in the calcium metabolic system. In order to maintain serum calcium within range PTH and vitamin D acts together in response to changes in serum-calcium levels. 25(OH)D concentration also being an important factor determining the levels of PTH.(5) Decreasing vitamin D leads to increasing levels of PTH. Hyperparathyroidism in patients with kidney-disease has in numerous studies been linked to cardiovascular disease, left ventricle hypertrophy, and valvular calcification .(6) Aim: Intervention with vitamin D and calcium will improve patients' vitamin D levels and suppress PTH. Thus we hope to find an improved cardiac function and quality of life in the intervention-group.
Comparison: Cardiac function (and other effect parameters - such as self-evaluated health) in the intervention group vs. in the placebo-group
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