Participants with CLL/SLL:
Participants in this study have been newly diagnosed chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) within the last 12 months.
The purpose of this research study is to see if vitamin D replacement in early stage CLL being managed with observation can improve the percentage of patients requiring treatment with conventional therapy at 36 months to that of CLL patients with normal vitamin D levels. Vitamin D and placebo in the study will be referred to as the “study drug.”
Participants with Lymphoma:
Participants in this research study have been diagnosed with previously untreated diffuse large B-cell lymphoma or T-cell lymphoma and will be receiving chemotherapy.
The purpose of this research study is to see if vitamin D replacement in lymphoma patients with low vitamin D levels can improve outcomes at 12 months to be equal to that of lymphoma patients with normal vitamin D levels. Vitamin D in the study will be referred to as the “study drug.”
Approximately 60 people will take part in this study conducted by investigators at the University of Iowa. A total of about 965 people will take part in this research study wide.