Ascorbate in Myelodysplastic Syndrome

Inclusion Criteria * Age ≥ 18 years. * Diagnosis of myelodysplastic syndrome (MDS) requiring treatment with a hypomethylating agent (HMA). * Higher-risk MDS per the Molecular International Prognostic Scoring System (IPSS-M) - Moderate High, High, or Very High risk categories. * No prior MDS-directed therapy, except: ≤ 1 prior cycle of azacitidine, decitabine, or oral decitabine-cedazuridine; or prior use of ESA, luspatercept, or imetelstat. Prior hydroxyurea use is allowed but continuation beyond Cycle 1 requires PI approval. * ECOG performance status 0-2. * Adequate organ function: Creatinine clearance \>45 mL/min; total bilirubin ≤1.5 × ULN; ALT and AST ≤3 × ULN. * Ability to provide written informed consent. * Willingness to comply with study visits, treatment, and contraception requirements. * Negative pregnancy test for women of childbearing potential at screening. Exclusion Criteria * MDS with isolated del(5q) eligible for lenalidomide therapy. * MDS/MPN overlap syndromes other than MDS. * Known hypersensitivity or allergy to ascorbate or azacitidine. * Pregnant or nursing individuals. * Inability or unwillingness to use adequate contraception. * Uncontrolled intercurrent illness including active infection, recent myocardial infarction (≤6 months), uncontrolled heart failure or arrhythmia, pulmonary edema, unstable angina, or significant psychiatric illness. * Renal disease requiring dialysis, diabetic nephropathy, renal transplant recipients, or history of oxalate nephropathy. * Paroxysmal nocturnal hemoglobinuria. * Uncontrolled HIV infection (patients on effective antiretroviral therapy with undetectable viral load within 6 months are eligible). * G6PD deficiency. * Use of warfarin (due to potential interaction with high-dose ascorbate). * Diabetic patients using fingerstick or continuous glucose monitors to adjust insulin doses (ascorbate can cause false readings). * Concurrent active malignancy, except adequately treated nonmelanoma skin cancer or curatively treated in situ cancers with \>2 years disease-free. * Systemic immunosuppressive therapy with prednisone ≥20 mg/day (or equivalent), except for inhaled or topical steroids. * Primary hemochromatosis or transfusion-related iron overload (ferritin \>1000 ng/mL).