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 58percent and 62percent in pediatric subjects, 44percent and 60percent in adults, and 41percent and 62percent in elderly, in the 2 study periods. At a cut-off 30 ng-ml, the prevalence was above 78percent, 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. © 2014 Elsevier Inc.