title: Efficacy and safety of vitamin D supplementation in patients with chronic lymphocytic leukemia.
abstract: BACKGROUND
  Vitamin D (VD) deficiency in chronic lymphocytic leukemia (CLL) is associated with inferior prognosis, shorter time to treatment and worse overall survival. VD deficiency is the first potentially modifiable prognostic factor in CLL. Currently, however, there is a lack of studies concerning VD supplementation in CLL patients.
  
  
  OBJECTIVE
  To evaluate the efficacy and safety of VD supplementation in patients with CLL.
  
  
  METHODS
  A 6-month interventional study was conducted in CLL patients with lower serum 25-OH-D3 concentrations (< 30 ng/ml) than currently recommended. Patients with VD insufficiency (20-30 ng/ml) received 2000 IU of cholecalciferol/day, patients with moderate deficiency (10-19.9 ng/ml) received 4000 IU/day, and patients with severe VD deficiency (<10 ng/ml) received 6000 IU/day.
  
  
  RESULTS
  In the analyzed group of 13 CLL subjects, only 1 patient had a VD level within the optimal range (30-80 ng/ml), 7 had an insufficient concentration, 4 had moderate deficiency, and 1 had severe deficiency. Secondary hyperparathyroidism was diagnosed in 4 subjects. Cholecalciferol supplementation (mean dose of 3384 ± 1211 IU) was followed by a significant increase in 25-OH-D3 concentration (from 17.3 ± 5.8 to 41.4 ± 17.5 ng/ml; p<0.05) and decrease in PTH (p<0.05). Five patients did not achieve the recommended 25-OH-D3 concentration. Calcium level remained unchanged and no patients developed hypercalcemia.
  
  
  CONCLUSIONS
  VD replenishment is safe and can be effectively achieved by means of the employed cholecalciferol dosage in the majority of patients. However, some subjects may require higher doses to obtain the optimal level and immune function.
authors.affiliation: Department of Internal Medicine and Oncological Chemotherapy, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Kubeczko
authors.affiliation: Clinical and Experimental Oncology Department, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Gliwice, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Nowara
authors.affiliation: Department of Internal Medicine and Oncological Chemotherapy, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Spychałowicz
authors.affiliation: Department of Internal Medicine and Oncological Chemotherapy, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
authors.forename: Kamil
authors.initials: K
authors.lastname: Wdowiak
authors.affiliation: Department of Internal Medicine and Oncological Chemotherapy, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Bednarek
authors.affiliation: Department of Internal Medicine and Oncological Chemotherapy, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
authors.forename: Dobromiła
authors.initials: D
authors.lastname: Karwasiecka
authors.affiliation: Department of Pathophysiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Chudek
authors.affiliation: Department of Internal Medicine and Oncological Chemotherapy, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Wojnar
mesh_terms: D000368:Aged; D002762:Cholecalciferol / Q000627:therapeutic use*; D002908:Chronic Disease; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000150:complications; D007945:Leukemia, Lymphoid / Q000150:complications*; D008297:Male; D008875:Middle Aged; D061214:Patient Safety; D016896:Treatment Outcome; D014807:Vitamin D / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications / Q000188:drug therapy*
chemical_list: D014807:Vitamin D; D002762:Cholecalciferol