title: When should we measure vitamin D concentration in clinical practice?
abstract: The many recently published data on vitamin D have raised much interest in the medical community. One of the consequences has been a great increase in the prescription of vitamin D concentration measurements in clinical practice. It must be reminded that only the measurement of 25-hydroxyvitamin D (25(OH)D) concentration is indicated to evaluate vitamin D status. Furthermore, since vitamin D insufficiency is so common, since treatment is inexpensive and has a large safety margin, and since we already have much data suggesting that besides its classic effects on bone and mineral metabolism, vitamin D may potentially be helpful for the prevention/management of several diseases, perhaps should it be prescribed to everyone without prior testing? In our opinion, there are however groups of patients in whom estimation of vitamin D status is legitimate and may be recommended. This includes patients in whom a "reasonably" evidence-based target concentration (i.e., based on randomized clinical trials when possible) should be achieved and/or maintained such as patients with rickets/osteomalacia, osteoporosis, chronic kidney disease and kidney transplant recipients, malabsorption, primary hyperparathyroidism, granulomatous disease, and those receiving treatments potentially inducing bone loss. Other patients in whom vitamin D concentration may be measured are those with symptoms compatible with a severe vitamin D deficiency or excess persisting without explanation such as those with diffuse pain, or elderly individuals who fall, or those receiving treatments which modify vitamin D metabolism such as some anti-convulsants. Measurement of Vitamin D concentrations should also be part of any exploration of calcium/phosphorus metabolism which includes measurement of serum calcium, phosphate and PTH.
authors.affiliation: Service des Explorations Fonctionnelles Hôpital Necker-Enfants malades, Assistance Publique-Hôpitaux de Paris, Paris, France. jean-claude.souberbielle@nck.aphp.fr.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Souberbielle
authors.forename: Marie
authors.initials: M
authors.lastname: Courbebaisse
authors.forename: Catherine
authors.initials: C
authors.lastname: Cormier
authors.forename: Charles
authors.initials: C
authors.lastname: Pierrot-Deseilligny
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Viard
authors.forename: Guillaume
authors.initials: G
authors.lastname: Jean
authors.forename: Etienne
authors.initials: E
authors.lastname: Cavalier
mesh_terms: D006801:Humans; D010018:Osteomalacia / Q000097:blood; D012279:Rickets / Q000097:blood; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D