The Effect of Vitamin D Supplementation on Quality of Life in Stage II-III Colorectal Cancer Patients Undergoing Adjuvant Chemotherapy: A Single-Blind, Randomized Controlled Trial.

INTRODUCTION: Colorectal cancer is the third most common cancer with the second highest mortality worldwide in 2020. Adjuvant chemotherapy is given for stage II-III colorectal cancer. However, there are side effects that decrease the patient's quality of life. Several studies have found that vitamin D could reduce the side effects of chemotherapy, but studies at Hasan Sadikin Hospital have not been done.

METHODS: A study regarding the effect of vitamin D supplementation on the quality of life of stage II-III colorectal cancer patients undergoing adjuvant chemotherapy from May 2022 to April 2023 at Hasan Sadikin Hospital was conducted. A single-blinded, randomized controlled trial (RCT) with consecutive sampling was done at the digestive surgery outpatients. Data was taken from the medical record, history taking, and personal interviews. Quality of life was measured at the first, third, and sixth months after chemotherapy using the validated Indonesian version of the EORTC QLQ-C30 questionnaire.

RESULTS: A total of 34 patients received vitamin D and 34 others received placebo. Serum vitamin D levels significantly increased (p < 0.001) in the intervention arm, from a median of 21.34 (5.26-29.95) to 27.92 (13.58-40.49). Meanwhile, it decreased in the placebo arm, from a median of 22.78 (8.3-29.93) to 21.37 (7.45-31.26). The patient's quality of life improved significantly after receiving vitamin D, compared with the placebo group on the third (median of 75.0 vs 45.83) and sixth (median of 83.33 vs 33.33) months after chemotherapy.

CONCLUSION: Vitamin D consumption (10,000 IU/day) could improve the quality of life of colorectal cancer patients undergoing adjuvant chemotherapy.