Despite strong evidence suggesting that vitamin D deficiency is associated with undesirable outcomes in patients with numerous cancers, there has never been a thorough study of vitamin D treatment in subjects undergoing treatment for cancer. The purpose of this study is to evaluate whether modification of vitamin D levels in the blood, through supplementation, can improve outcomes. 
-Randomization arms 
-Placebo- Yes 
-A placebo is a substance that looks like the study supplement but doesn’t include any active ingredients. 
-Oral daily dose of either 2,000 IU vitamin D supplementation or placebo 
-Complete study visit every 3 months 
-Length of time on treatment is approximately 3 years or until you stop responding to treatment and not experiencing unacceptable side effects.