High-Dose vs Standard Ergocalciferol for Vitamin D Normalization in Aggressive Non-Hodgkin Lymphoma

Inclusion criteria

• Age ≥ 20 years.
• Newly diagnosed aggressive non-Hodgkin lymphoma, confirmed by histopathological examination according to the WHO Classification of Haematolymphoid Tumours, 5th edition, with an indication for standard first-line chemoimmunotherapy
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-3.
• Serum 25-hydroxyvitamin D level < 30 ng/mL within 14 days prior to randomization.
• Adequate organ function to receive full-dose standard chemotherapy.
• Ability to provide written informed consent.

Exclusion criteria

• Mild hypercalcemia (corrected Ca > 10.4 mg/dL)
• Hyperphosphatemia (PO4 > 4.5 mg/dL)
• History of urolithiasis associated with hypercalciuria or a diagnosis of primary hyperparathyroidism.
• Chronic kidney disease stage 4 or higher (estimated glomerular filtration rate [eGFR] < 30 mL/min/1.73 m²).
• Inability to take oral medication, active gastrointestinal bleeding, or malabsorption syndrome.
• Pregnancy or breastfeeding.
• Prior systemic therapy for lymphoma.
• Ongoing tumor lysis syndrome requiring urgent treatment.
• Prior use of vitamin D supplements (ergocalciferol or cholecalciferol).

Withdrawal Criteria:

• Development of mild hypercalcemia.
• Development of mild hypophosphatemia.
• Development of hypervitaminosis D.
• Occurrence of severe adverse events (AEs) or side effects for which the investigator considers discontinuation of the study drug necessary for patient safety.
• Investigator's judgment that continued participation may pose a safety risk, such as the occurrence of serious infection, febrile neutropenia, or organ failure.
• Non-adherence to study medication, defined as cumulative vitamin D₂ intake of less than 80% of the expected cumulative dose at the time of serum vitamin D assessment.
• Participant withdrawal of consent to continue participation in the study.