This study is a non-interventional, specimen collection translational study to evaluate vitamin C levels in the peripheral blood of Acute Myeloid Leukemia (AML), Myelodysplastic Syndrome (MDS), or Chronic Myelomonocytic Leukemia (CMML) patients.

It has previously been established that hematological cancer patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) often exhibit severe vitamin C deficiency from a cohort of patients in Copenhagen. In this study, the investigators aim to determine if those results are conserved in another population/geographical location.

Inclusion Criteria:

• Patients actively receiving treatment for acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), or chronic myelomonocytic leukemia (CMML).
• Patients diagnosed with AML, MDS, or CMML and are treatment naïve.
• Patients who are 18 years old or older.

Exclusion Criteria:

• Patients deemed as too ill to participate as determined by the clinical investigator.
• Non-English speaking patients
• Patients unable to provide informed consent.

Patients seen in hematology/oncology clinics in Grand Rapids, MI