Vitamin A and D Supplementation in Allogeneic HCT

This study is looking at whether giving Vitamin A and Vitamin D supplements to patients undergoing a donor stem cell transplant (allogeneic HCT) for blood cancers can reduce complications and improve outcomes after the procedure. **You may be eligible if...** - You are 18 years or older - You have been diagnosed with a blood cancer such as leukemia (AML or ALL), myelodysplastic syndrome, chronic myeloid leukemia, lymphoma, or myeloma - Your disease is in remission or at least partial response before the transplant - You have a compatible donor (fully matched related donor, or 9–10 out of 10 matched unrelated donor) - You do not have other serious health conditions that would prevent the transplant **You may NOT be eligible if...** - Your disease is not in adequate remission before transplant - You do not have a compatible donor - You have serious other illnesses that could interfere with the study Talk to your doctor to see if this trial is right for you.