title: Hypovitaminosis D in the Middle East and North Africa: Prevalence, risk factors and impact on outcomes.
abstract: BACKGROUND
  The Middle East and North Africa (MENA) region registers some of the highest rates of hypovitaminosis D worldwide.
  
  
  OBJECTIVE
  We systematically reviewed the prevalence of hypovitaminosis D, rickets and osteomalacia, their predictors and impact on major outcomes, in the region.
  
  
  METHODS
  Medline, Pubmed and Embase search engines, entering keywords and concepts, combined with individual countries of interest, were used. Search was limited years 2000-2012; and review articles were used for the period preceding year 2000.
  
  
  RESULTS
  Rickets and osteomalacia still occur in this sunny region. Hypovitaminosis D prevails, with rates varying 30-90%, considering a desirable serum 25 hydroxy-vitamin D [25(OH)D] of 20 ng/ml. Advancing age, female gender, multi-parity, clothing style, season, socio-economic status and urban living are recognized predictors of hypovitaminosis D in adults. Prolonged breastfeeding without vitamin D supplementation and low dietary calcium intake are the recognized risk factors for rickets and hypovitaminosis D in children.. Associations with pain score and disease activity in rheumatologic disorders, viral load and interleukins in hepatitis C, BMI, lipids and insulin sensitivity, blood pressure, heart failure and mortality are described. Sun exposure in adults decreased prevalence of metabolic syndrome in one study. Few randomized vitamin D trials revealed that the majority of mothers or children failed to achieve a desirable 25(OH)D level, even with doses by far exceeding current recommendations. A trial in adolescent girls reveals substantial bone and lean mass increments.
  
  
  CONCLUSIONS
  Hypovitaminosis D is prevalent in MENA. The lack of populations based studies, gaps in studies in infants, pre-pubertal children and pregnant women, hinder the development of region specific guidelines and constitute a major obstacle to impact this chronic and most often subclinical disease.
authors.affiliation: Calcium Metabolism and Osteoporosis Program; WHO Collaborating Center for Metabolic Bone Disorder; Faculty of Medicine; American University of Beirut Medical Center; Beirut, Lebanon.
authors.forename: Darina
authors.initials: D
authors.lastname: Bassil
authors.forename: Maya
authors.initials: M
authors.lastname: Rahme
authors.forename: Maha
authors.initials: M
authors.lastname: Hoteit
authors.forename: Ghada El-Hajj
authors.initials: Gel-H
authors.lastname: Fuleihan
keywords: genetics polymorphisms; infections; musculoskeletal outcomes; osteomalacia; pleotropic; policy; prevalence; region specific guidelines; rickets; risk factors