 These parameters will be tested in randomised placebo controlled trial involving 25 patients in each arm. 25 hydroxy vitamin D3 25 OH D has been used in this proposal, as CKD stage 3-4 patients would be expected to have adequate stores of 1 α-hydroxylase enzyme to convert 25 OH D to active 1,25 OH2 D. The investigators will measure the level of 25 hydroxy colecalciferol to ensure adequate repletion. Colecalciferol has been shown to be safe and effective when given at this dose18;19. To examine the improvement in ECM composition and turnover the investigators will demonstrate reduction in cardiac collagen content as measured by decrease in serum PICP and Tissue inhibitor of metalloproteinases 1TIMP1 and an increase in serum Matrix metalloproteinase 1 MMP1. PICP will be corrected for eGFR and bone alkPO4. MMP1TIMP1 ratio will be used to measure the collagen degradation. Cardiac function pre and post therapy, will also be assessed by measuring plasma N-Terminal proBNP NT proBNP. Furthermore, a biobank of whole cells, mRNA and DNA, blood and urine will be created for future analysis of novel genes or biological pathways. 