Conditions: Heart Failure
Keywords: Vitamin D Systolic failure Genomics Biomarkers Exercise Quality of Life
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 28
Healthy volunteers: no

Brief summary:
The central objective of this proposal is to establish that vitamin D supplementation in heart failure patients with low vitamin D levels will have improved outcomes compared to placebo. In addition the investigators will also evaluate the role of genetics in regard to vitamin D and heart failure. The investigators will be evaluating what is currently a novel approach of identifying patients with low vitamin D and treating this low vitamin D level. The investigators will be able to evaluate the importance of vitamin D supplementation in these patients and the role of genetics on our defined outcomes.

Detailed description:
Primary Objective To determine how rapid vitamin D supplementation affects biomarkers and submaximal exercise capacity in systolic HF patients with low vitamin D status.

Working Hypothesis 1: HF patients when supplemented with vitamin D for 6 months will have lower measures of inflammation and extracellular-matrix remodeling compared with placebo.

Working Hypothesis 2: HF patients when supplemented with vitamin D for 6 months will have longer 6-minute walk length compared with placebo.

Secondary Objectives To establish a relationship between the CYP2R1 variant and surrogate markers in systolic HF patients.

Working Hypothesis 3: HF patients with the CYP2R1 G allele will have higher measures of inflammation and extracellular-matrix remodeling compared to AA subjects. This relationship will also be seen in subjects with the CYP2R1 TagSNP variants.

Working Hypothesis 4: HF patients with CYP2R1 variant alleles will have shorter 6-minute walk length compared to subjects without these variants.

To genotype HF subjects for the VDR variants and additional tag SNPs, to ascertain the relationship between VDR genetic variation and surrogate markers in systolic HF patients.

Working Hypothesis 5: HF patients with VDR variants will have greater measures of inflammation and extracellular-matrix remodeling compared to subjects without VDR variants.

Working Hypothesis 6: HF patients with VDR variants will have a shorter 6-minute walk length compared to subjects without these variants.

Arms:
arm 1: Vitamin D supplementation will be an oral load of 100,000 IU then 2000 IU by mouth daily of vitamin D3 (cholecalciferol)for 6 months arm 2: A placebo loading dose will be given followed by two placebo tablets daily for 6 months.

Interventions: intervention 1: Vitamin D3 intervention 2: Placebo
Intervention descriptions: intervention 1: Vitamin D supplementation will be an oral load of 100,000 IU then 2000 IU by mouth daily of vitamin D3 (cholecalciferol)for 6 months intervention 2: A placebo loading dose will be given followed by 2 placebo tablets daily for 6 months.

Protocol document: