title: Vitamin D status: effects on quality of life in osteoporosis among Turkish women.
abstract: OBJECTIVE
  Vitamin D deficiency causes muscle weakness, impairs bone formation and neuromuscular coordination thus leading to an increase in fracture risk. It has been found that inadequate levels of vitamin D are present in most of the osteoporosis patients. However, very few studies investigate the association between vitamin D status and quality of life (QOL). The aim of this study is to investigate the effects of vitamin D on QOL among Turkish women with osteoporosis.
  
  
  METHODS
  259 patients (61.0 +/- 8.9 years) with osteoporosis were evaluated by physical activity level, back pain, bone turnover markers, 25-hydroxyvitamin D [25(OH)D], parathyroid hormone levels and bone mineral density. QOL was assessed using QOL Questionnaire of the European Foundation for Osteoporosis (QUALEFFO). 25(OH)D levels below 20 ng/ml was defined as vitamin D insufficiency, below 12 ng/ml as vitamin D deficiency.
  
  
  RESULTS
  Mean 25(OH)D level was 22.7 +/- 12.6 ng/ml and mean total QUALEFFO score was 43.3 +/- 14.9. Vitamin D levels were significantly correlated with all subscales and total score of QUALEFFO (r = -0.25, P = 0.0001). Vitamin D insufficiency was determined in 132 patients (51%). In vitamin D deficient (<12 ng/ml) group all subscales and total QOL were found to be poorer when compared with the groups whose vitamin D levels were > or = 12 and <20 ng/ml and > or = 20 ng/ml (effect sizes 0.41 and 0.62 respectively, P = 0.0001 for total QOL). Vitamin D level, education, concomitant diseases, physical activity level and pain severity were found to be significantly associated with QOL in multiple linear regression analysis model.
  
  
  CONCLUSIONS
  Vitamin D insufficiency affects physical, social and mental functions of osteoporosis patients and impairs QOL. Vitamin D was found to be one of the factors affecting QOL.
authors.affiliation: Faculty of Medicine, Department of Physical Medicine and Rehabilitation, Cukurova University, Adana 01330, Turkey. sbasaran@cu.edu.tr
authors.forename: Sibel
authors.initials: S
authors.lastname: Basaran
authors.forename: Rengin
authors.initials: R
authors.lastname: Guzel
authors.forename: Ilke
authors.initials: I
authors.lastname: Coskun-Benlidayi
authors.forename: Fusun
authors.initials: F
authors.lastname: Guler-Uysal
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000503:physiopathology / Q000523:psychology*; D011788:Quality of Life; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D014421:Turkey; D014808:Vitamin D Deficiency / Q000503:physiopathology / Q000523:psychology*; D016387:Women's Health