title: The relationship between serum 25-hydroxy vitamin D, parathormone and bone mineral density in Indian population.
abstract: OBJECTIVE
  Vitamin D deficiency (VDD) is a global problem. Not all patients with VDD have clinical manifestations or secondary hyperparathyroidism. We studied the interaction between serum 25-hydroxy vitamin D (25OHD), parathormone (PTH) and bone mineral density (BMD) in Indian adolescents and adults.
  
  
  METHODS
  Population survey.
  
  
  METHODS
  A total of 1829 adolescents and 1346 adults aged 50 years and above were analysed in this study.
  
  
  METHODS
  Serum biochemistry, 25OHD, PTH and BMD were estimated. Subjects were grouped according to quartiles of serum PTH. VDD was defined as severe (25OHD ≤ 5 ng/ml), moderate (25OHD ≤ 10 ng/ml) and mild (25OHD ≤ 20 ng/ml) and secondary hyperparathyroidism (SHPT) when serum PTH levels >65 pg/ml.
  
  
  RESULTS
  Only 30-40% of subjects with moderate and severe VDD, respectively, had SHPT. BMD decreased from Quartile 1 to Quartile 4 of PTH at all sites among adolescents and adults, with only a marginal decline in serum 25OHD levels between these quartiles. Further, within each PTH quartile, there was no difference in BMD according to categories of VDD. Analysing BMD in the different PTH quartiles, the PTH cut-offs beyond which BMD showed a significant decline, was 35 pg/ml in adolescents and 53 pg/ml in adults.
  
  
  CONCLUSIONS
  Less than half of the subjects with VDD have SHPT. BMD levels start to decline at PTH values currently considered to be normal. These data suggest the need to redefine SHPT in different age groups keeping in mind the relationship between PTH and BMD. This may also influence the decision to supplement subjects with VDD.
authors.affiliation: Department of Endocrinology and Metabolism, Command Hospital (Southern Command), Pune, Maharashtra, India.
authors.forename: M K
authors.initials: MK
authors.lastname: Garg
authors.forename: N
authors.initials: N
authors.lastname: Tandon
authors.forename: R K
authors.initials: RK
authors.lastname: Marwaha
authors.forename: A S
authors.initials: AS
authors.lastname: Menon
authors.forename: N
authors.initials: N
authors.lastname: Mahalle
mesh_terms: D000293:Adolescent; D015519:Bone Density / Q000502:physiology*; D002648:Child; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D