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 anaemia 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 266 μg 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.