Vitamin D treatment in myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are a group of clonal disturbances with defective cellular differentiation. Vitamin D3 (VD) analogues can act on the differentiation and maturity of different cell lines. We studied the effects of VD on a series of patients with MDS in an open-design trial. Nineteen patients, 12 men and seven women, with MDS were included. Patients were 74:8 ± 5.6 years (mean ± SD), seven had refractory anaemic with ringed sideroblasts, five had refractory anaemia, one had refractory anaemia with excess of blasts and six had chronic myelomonocytic leukaemia. All the patients were in a low to intermediate risk group. Mean follow-up period was 26°21 months, range 9-75. Responders were defined as follows: granulocyte or platelet count increase by 50%, or haemoglobin increase of 1.5 g/dl or transfusion needs decrease by 50%. The first five patients received 266μg of calcifediol three times a week and the other 14 received calcitriol (0.25- 0.75 μg/d). Response was observed in 11 patients. In the calcifediol- treated group, one case responded, three were non-responders, and one showed progression. In the calcitriol group, 10 were responders (two with major response), and four were non-responders. No correlation was observed between baseline levels of vitamin D metabolites and the presence of response. No hypercalcaemia was observed. Treatment with vitamin D3 metabolites could induce a long-standing response of the haematological disturbance in some low-intermediate risk MDS patients without inducing hypercalcaemia.