title: Prevalence and correction of severe hypovitaminosis D in patients over 50 years with a low-energy fracture.
abstract: OBJECTIVE
  To examine the increase in serum 25(OH) vitamin D levels after supplementation with 800 IU/day of vitamin D in patients with low vitamin D levels and which factors affected the increase in vitamin D levels.
  
  
  METHODS
  The study included patients > 50 years with a low-energy fracture and a vitamin D level < 30 nmol/l. This was a retrospective study and was carried out at a large non-teaching hospital in the Netherlands.
  
  
  RESULTS
  82 patients were included, mean basal 25(OH) vitamin D level was 21.2 nmol/l. After a mean of 9.8 weeks, the mean increase in vitamin D was 48.5 nmol/l. Only 45.1% reached the target level of > 50 nmol/l. The increase was correlated with the basal level of vitamin D (p < 0.05), and the time interval between the two vitamin D measurements (p < 0.05) and was inversely related to body weight (p < 0.05), but was not related to age, gender or renal function.
  
  
  CONCLUSIONS
  We found that the generally recommended dosage of 800 IU of vitamin D per day resulted in suboptimal serum levels after ten weeks of treatment in more than half of the patients. The increase in vitamin D levels was higher in patients with low body weight and in patients with very low basal vitamin D levels. These data suggest that these patients should initially be treated with higher dosages of vitamin D. If not possible, vitamin D measurements should be performed after at least six months of supplementation with dosage adjustment.
authors: Department of Rheumatology, St. Antonius Hospital, Utrecht÷Nieuwegein, the Netherlands.
authors: E-J
authors: EJ
authors: ter Bor
authors: W
authors: W
authors: van den Hoeven-van Kasteel
authors: J C
authors: JC
authors: Kelder
authors: W F
authors: WF
authors: Lems
mesh_terms: D000368:Aged; D019587:Dietary Supplements; D005260:Female; D050723:Fractures, Bone / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D008297:Male; D009426:Netherlands; D015995:Prevalence; D012189:Retrospective Studies; D014807:Vitamin D / Q000493:pharmacokinetics*; D014808:Vitamin D Deficiency / Q000150:complications / Q000453:epidemiology* / Q000628:therapy
chemical_list: D014807:Vitamin D