Vitamin D3 Supplementation for Heart Failure Patients

Heidi Moretti, MS, RD40 enrolled

Overview

The purpose of this study is to determine if treatment with vitamin D3 of 10,000 International Units (IU) daily in vitamin D deficient patients for 6 months will improve B type natriuretic peptide (BNP), a marker of heart function, compared to placebo. The investigators also aim to determine if vitamin D helps cardiopulmonary function as evaluated by cardiopulmonary exercise test (CPX), laboratory values, strength, and quality of life in patients with stable congestive heart failure (Class II or III).

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Enrollment

Conditions

Heart Failure Vitamin D Deficiency Cardiomyopathy Congestive Heart Failure

Interventions

Outcomes

Primary Outcomes

B type Natriuretic Peptide (BNP)

BNP is a hormone secreted by the heart ventricles, and high concentrations of this hormone occur in heart failure. It is a strong prognostic indicator.

Time frame: Change in BNP will be measured at baseline and after 6 months of treatment with vitamin D or placebo

Secondary Outcomes

Cardiopulmonary exercise test (CPX)

Secondary outcome measure will include improvements from baseline in cardiopulmonary function as evaluated by CPX(includes measurement of the change in ventilator efficiency (VE/VCO2), partial pressure of end-tidal CO2 (PETCO2)

Time frame: Change in CPX will be measured at baseline and after 6 months of treatment with Vitamin D3 or placebo

25 hydroxyvitamin D [25 (OH)D]

Patients with vitamin D deficiency as defined by 25(OH)D of less than 32 ng/ml. 25(OH)D is the most accurate measurement for assessment of vitamin D status. However, ideal ranges for serum 25 (OH)D have not been well established. A recent pharmokinetic study conducted by Hollis, et al, found that 25 OHD levels had to exceed 40 ng/ml and sometimes 50 ng/ml, for the parent substrate (cholecalciferol) to be detectable in the blood (Hollis 2007. IF 25(OH)D levels exceed 150 ng/ml, they will be withdrawn from the study to avoid toxicity.

Time frame: Change in 25 hydroxyvitamin D will be measured at baseline, at 12 weeks, and after 6 months of treatment with vitamin D or placebo

C reactive protein (CRP)

CRP is related to heart failure incidence, and vitamin D seems to be inversely related to CRP levels.

Time frame: Change in CRP will be measured at baseline and after 6 months of treatment with vitamin D or placebo

Serum Calcium

Measurement of serum calcium levels will help to assess safety of vitamin D treatment. If serum calcium becomes elevated, patients will be withdrawn from the clinical trial.

Time frame: Change in serum calcium levels will be measured at baseline, at 12 weeks, and at 6 months of treatment with vitamin D or placebo

6 minute walk test

The 6 minute walk test is used to measure aerobic activity at baseline and after completion of supplemental vitamin D or placebo. This test is an objective measurement of exercise capacity, and has been shown to be reproducible and a suitable measure for outcome in patients with heart failure (Guyatt). The 6 minute walk test in heart failure patients is strongly associated with vitamin D serum concentrations (p=0.002) and inversely with high sensitivity C reactive protein (hsCRP), an inflammatory marker (p=0.001)

Time frame: Change in the 6 minute walk test will be measured at baseline and at 6 months of treatment with vitamin D or placebo

Kansas City Cardiomyopathy Questionnaire

Measurements of quality of life provide means of measuring prospective benefits of heart failure interventions. The KCCQ is associated with hospitalization and mortality, and is sensitive to changes in heart function with ARB, beta-blocker and ACE inhibitor treatment.

Time frame: Chang in the KCCQ will be measured at baseline and after 6 months of treatment with vitamin D or placebo