Borchmann S, Cirillo M, Goergen H, et al. - Researchers investigated the correlation of pretreatment vitamin D levels with clinical outcomes in prospectively treated patients with Hodgkin lymphoma (HL). Participants were patients (n = 351) from the German Hodgkin Study Group clinical trials (HD7, HD8, and HD9). Impaired progression-free survival and overall survival were noted in relation to vitamin D deficiency, a finding that was consistent across trials and treatment groups. Vitamin D status was identified as an independent predictor of outcome. They hypothesized the possible significance of vitamin D status for the chemosensitivity of HL. Increased antiproliferative effects in combination with chemotherapy were revealed in experiments supplementing physiologic doses of vitamin D (calcitriol) to cultured HL cell lines. The improvement of chemosensitivity of tumors by supplemental vitamin D (dietary supplement, cholecalciferol), via attenuating the rate of tumor growth, was demonstrated in comparison with vitamin D or chemotherapy alone in an HL-xenograft animal model. The inclusion of vitamin D screening and replacement into future randomized clinical trials was encouraged, depending on these clinical and preclinical findings, to properly define the role of vitamin D replacement therapy in HL.