title: Subclinical vitamin D deficiency.
abstract: The optimal vitamin D status, as defined by serum 25-hydroxyvitamin D [25(OH)D], is still controversial. Some individuals are at risk for subclinical vitamin D deficiency, as defined by serum 25(OH)D levels between 25 and 75 nmol/L, and up to 80-100% of the entire population can display inadequate serum 25(OH)D values depending on latitude and seasonality. The clinical manifestation of extreme vitamin D deficiency, i.e. rickets and osteomalacia, are rare. Levels of 25(OH)D ≥ 50 nmol/L are required for optimal musculoskeletal health. However, levels of 25(OH)D above 75 nmol/L may be necessary to maximize musculoskeletal benefits and take advantage of the extraskeletal actions of vitamin D. This review will summarize the actual positions on the boundaries of subclinical vitamin D deficiency, the main available evidence on the effects of inadequate vitamin D status on skeletal and extraskeletal targets and supplementation strategies.
authors.affiliation: Department of Endocrinology and Metabolism, Unit of Endocrinology and Bone Metabolism, University of Pisa, University Hospital of Pisa, Via Paradisa, 2 - 56124 Pisa, Italy.
authors.forename: Luisella
authors.initials: L
authors.lastname: Cianferotti
authors.forename: Claudio
authors.initials: C
authors.lastname: Marcocci
mesh_terms: D019587:Dietary Supplements; D006801:Humans; D010018:Osteomalacia / Q000097:blood / Q000175:diagnosis* / Q000178:diet therapy; D014807:Vitamin D / Q000097:blood / Q000627:therapeutic use; D014808:Vitamin D Deficiency / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy
chemical_list: D014807:Vitamin D