Mapping the Evidence on Vitamin D, Vitamin B12, and Folate Deficiencies and Their Potential Impact on Treatment Outcomes in Patients With Cancer in Sub-Saharan Africa: Protocol for a Scoping Review

Background

Micronutrient deficiencies, particularly of vitamin D, vitamin B12, and folate, are increasingly recognized as important, yet underexplored contributors to adverse outcomes in oncology care. These micronutrients are essential for immune regulation, DNA synthesis and repair, cell proliferation, and metabolic homeostasis, all of which are frequently disrupted in patients with cancer. Deficiencies may arise due to cancer-related metabolic changes, malabsorption, anorexia, and treatment-related toxicities, potentially influencing therapeutic response, treatment tolerance, survival, and quality of life. Despite growing evidence, findings remain fragmented across cancer types, treatment modalities, and geographical settings.