The use of vitamin D in the context of lymphoma is primarily supported by emerging scientific interest rather than established clinical validation or long-standing tradition. Epidemiological studies have observed that patients with lymphoma, particularly non-Hodgkin lymphoma, may have lower levels of serum vitamin D compared to healthy controls. Some observational research suggests that higher vitamin D levels at diagnosis are associated with better prognosis and improved survival rates in lymphoma patients. For example, a 2010 study in the journal Journal of Clinical Oncology found that higher vitamin D levels were linked to improved event-free and overall survival in patients with diffuse large B-cell lymphoma.

Mechanistically, vitamin D has known immunomodulatory properties and may influence cell proliferation, apoptosis, and differentiation, processes that are relevant to cancer development and progression. Experimental studies in vitro have shown that vitamin D analogs can induce cell cycle arrest and apoptosis in lymphoma cell lines.

However, the evidence for vitamin D as a treatment or supportive therapy for lymphoma is still preliminary. Most data are from observational studies and laboratory experiments; randomized controlled trials specifically assessing vitamin D supplementation as an adjunct therapy for lymphoma are lacking. Thus, while there is a scientific rationale and some observational support, the evidence is currently weak (rated 2/5), and vitamin D is not considered a standard or primary therapy for lymphoma. Ongoing research may clarify its potential role in the future.