title: Hypovitaminosis D in a sunny country: time trends, predictors, and implications for practice guidelines.
abstract: The aim of the current study is to investigate the prevalence of hypovitaminosis D in Lebanese subjects, its robust predictors, evaluate the relationship between 25 hydroxy vitamin D [25(OH)D] and parathyroid hormone levels, and derive desirable vitamin D levels, based on a large hospital laboratory database spanning all age groups. Data from a large representative digitized database of 9147 subjects, mostly outpatients, evaluated between 2000-2004 and 2007-2008, in whom information on age, gender, service, and time of the year, was analyzed. The PTH-25(OH)D relationship was studied in a subset of 657 adult subjects, in whom such data were available. At a 25(OH)D cut-off of<20 ng/ml, the prevalence of hypovitaminosis D ranged between 58% and 62% in pediatric subjects, 44% and 60% in adults, and 41% and 62% in elderly, in the 2 study periods. At a cut-off <30 ng/ml, the prevalence was above 78%, in most sub-groups. Regardless of cut-off used, the only significant predictors of high mean 25(OH)D levels were the male gender in the pediatric group, and female gender in adults and elderly, summer/fall seasons, out-patient status, as well as study period. Curve fitting of the PTH-25(OH)D relationship, in adults and elderly, revealed a plateau at 25(OH)D levels of 17-21 ng/ml, depending on sub-study group. Hypovitaminosis D is prevalent in our sunny country, even using a conservative population-derived cut-off of 20 ng/ml, and thus the need for a public health strategy for supplementation.
authors.affiliation: Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorder, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Maha
authors.initials: M
authors.lastname: Hoteit
authors.affiliation: Vascular Medicine Program, Faculty of Medicine, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Laila
authors.initials: L
authors.lastname: Al-Shaar
authors.affiliation: Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorder, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Yazbeck
authors.affiliation: Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorder, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Maria
authors.initials: M
authors.lastname: Bou Sleiman
authors.affiliation: Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorder, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Tala
authors.initials: T
authors.lastname: Ghalayini
authors.affiliation: Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorder, American University of Beirut Medical Center, Beirut, Lebanon. Electronic address: gf01@aub.edu.lb.
authors.forename: Ghada El-Hajj
authors.initials: Gel-H
authors.lastname: Fuleihan
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood; D000046:Academic Medical Centers; D000328:Adult; D000368:Aged; D002112:Calcifediol / Q000097:blood; D002648:Child; D002980:Climate; D003430:Cross-Sectional Studies; D019587:Dietary Supplements; D005260:Female; D006293:Health Promotion; D006801:Humans; D007861:Lebanon / Q000453:epidemiology; D008297:Male; D018673:Nutrition Policy; D010281:Parathyroid Hormone / Q000097:blood; D017410:Practice Guidelines as Topic; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D014807:Vitamin D / Q000627:therapeutic use; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control
chemical_list: C470125:PTH protein, human; D010281:Parathyroid Hormone; D014807:Vitamin D; D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol
keywords: Age; Cut-offs; Gender; PTH; Plateau; Season