title: Vitamin D levels for optimum bone health.
abstract: BACKGROUND
  Vitamin D deficiency was assessed previously on the basis of rickets and osteomalacia, which represent an extreme end of the spectrum. As a result of this, many clinically-asymptomatic patients go undetected. As vitamin D deficiency results in secondary hyperparathyroidism, we propose to use the normalisation of intact parathyroid hormone (iPTH) as a surrogate marker for assessing the adequacy of vitamin D nutrition.
  
  
  METHODS
  A descriptive study was undertaken on 195 premenopausal Pakistani women. 25-hydroxy-cholecalciferol and iPTH levels were measured by standard laboratory techniques.
  
  
  RESULTS
  The minimum level of vitamin D required to keep iPTH below 53 pg/dL was found to be 16 ng/ml with a 95 percent confidence interval of 13.8 and 18.2. Existing normal range is 9-36 ng/ml.
  
  
  CONCLUSIONS
  Normalisation of iPTH if taken as a criterion for judging vitamin D deficiency can lead to detection of clinically asymptomatic patients. The simplicity, low cost of correction, and the potential beneficial skeletal and non-skeletal consequences of doing so makes it essential that this criterion be used to redefine the optimal vitamin D levels. This should be internationally standardised and made available to clinicians.
authors.affiliation: Department of Medicine, Services Institute of Medical Sciences, Services Hospital, Jail Road, Lahore 54700, Pakistan. dr.faisalmasud@gmail.com
authors.forename: F
authors.initials: F
authors.lastname: Masud
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood*; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood / Q000517:prevention & control; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D012621:Seasons
chemical_list: D010281:Parathyroid Hormone; D015652:25-Hydroxyvitamin D 2