title: The role of vitamin D deficiency and osteoporosis in breast cancer.
abstract: OBJECTIVE
  Epidemiological studies suggest an association between vitamin D and calcium intake and breast cancer. The aim of this study was to determine the association of breast cancer with vitamin D deficiency and osteoporosis according to menopausal status and to examine vitamin D and bone mineral density (BMD) levels in breast cancer patients.
  
  
  METHODS
  This was an observational cohort hospital-based study. It included 635 patients with breast cancer. Socio-demographic information, type of consanguinity, menopause status, medical history, lifestyle habits, dietary intake, BMD measurements and vitamin D levels were collected. Descriptive and univariate analyses were performed.
  
  
  RESULTS
  Of the studied patients, 36.1% were Qataris, 63.9% non-Qatari Arabs, 40% premenopausal women, 20.9% university graduates and 37.2% housewives. Overall, 31.8% of breast cancer women were affected with osteopenia/osteoporosis. Vitamin D deficiency (10.7% vs. 7.9%) and severe vitamin D insufficiency (39.2% vs. 32.5%) were higher in postmenopausal women than premenopausal women (P < 0.001). Low physical activity (< 30 min/day) was observed among vitamin D deficient (46.8%) and osteoporotic (45%) women. Dietary intake of vitamin D was significantly lower in vitamin D deficient women; these included dairy products (33.1%), milk (38.6%), seafood (39.6%), (P < 0.001) and for osteoporotic women, dairy products (46%), calcium (21.3%), milk (36.1%), yoghurt (37.6%), cheese (37.6%) and sea food (34.7%) (P < 0.001).
  
  
  CONCLUSIONS
  The present study findings revealed a high prevalence of vitamin D deficiency and osteoporosis in breast cancer patients. Also, the dietary intake of vitamin D and calcium was significantly lower in breast cancer women.
authors.affiliation: Department of Medical Statistics & Epidemiology, Hamad Medical Corporation, Hamad General Hospital, Doha, Qatar. abener@hmc.org.qa
authors.forename: Abdulbari
authors.initials: A
authors.lastname: Bener
authors.forename: Hanadi R
authors.initials: HR
authors.lastname: El Ayoubi
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D001943:Breast Neoplasms / Q000453:epidemiology*; D016009:Chi-Square Distribution; D004032:Diet; D019587:Dietary Supplements; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging; D006801:Humans; D008019:Life Style; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008593:Menopause; D008875:Middle Aged; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000453:epidemiology*; D015995:Prevalence; D011780:Qatar / Q000453:epidemiology; D012042:Registries; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D