Vitamin D is known to play a major role in maintaining calcium level and skeletal homeostasis, besides its well-known pleiotropic effect on the cellular differentiation, proliferation , apoptosis and angiogenesis One of the most potent effect of extra-renal  25(OH) vitamin D is the regulation of cell proliferation which occurs through the increased transcription of two cell cycle negative regulators which is known as (p21 and p27), induction of apoptosis and increased cell proliferation signals.

Vitamin D insufficiency has been found to be associated with higher incidence of NHL, besides the lower levels are linked with poor prognosis. Our study was conducted to assess vitamin D level in newly diagnosed chronic lymphocytic leukemia (CLL) and diffuse large B- cell lymphoma (DLBC) patients. In addition, grade of lymphoma was evaluated with the relation of hypo-vitaminosis D and adverse prognostic parameters. 74 patients (50% CLL and 50% DLBCL) were enrolled in this study. All patients with CLL had vitamin D insufficiency which correlated with advanced Rai and Binet stage. About 91.8% of DLBCL patients had vitamin D insufficiency which correlated with bad ECOG performance, advanced Ann-Arbor staging, high LDH and extranodal involvement. Vitamin D levels in the CLL group were significantly lower than DLBCL group. However, we could not detect an impact of the severity of deficiency on the lymphoma grade.