title: Prevalence and functional significance of 25-hydroxyvitamin D deficiency and vitamin D receptor gene polymorphisms in Asian Indians.
abstract: BACKGROUND
  Recent studies show a wide prevalence of hypovitaminosis D in Asian Indians.
  
  
  OBJECTIVE
  The objective was to assess the functional significance of 25-hydroxyvitamin D [25(OH)D] deficiency, vitamin D receptor (VDR) gene, and parathyroid hormone (PTH) gene polymorphisms in relation to bone mineral density (BMD) in urban Asian Indians.
  
  
  METHODS
  Serum total calcium, inorganic phosphorus, alkaline phosphatase, 25(OH)D, intact PTH, and BMD at lumbar spine, proximal femur, and forearm were measured in 105 adult subjects. The genotyping related to VDR (BsmI, FokI, and TaqI) and PTH (BstBI and DraII) gene single-nucleotide polymorphisms was carried out by polymerase chain reaction-restriction fragment length polymorphism analysis.
  
  
  RESULTS
  The mean serum 25(OH)D concentration in the whole cohort was 9.8 +/- 6.0 ng/mL, which was inversely related with serum intact PTH values (P = 0.042). Ninety-nine (94.3%) of the 105 subjects had vitamin D deficiency with 25(OH)D concentrations < 20 ng/mL. The age- and body mass index (BMI)-adjusted BMD value at the hip was higher in subjects with serum 25(OH)D values > 9.0 ng/mL than in those with values < or = 9.0 ng/mL (0.893 +/- 0.114 compared with 0.839 +/- 0.112 g/cm2, respectively; P = 0.001). The mean forearm and spine BMD values in subjects with TT (VDR, TaqI) or bb (PTH, BstBI) genotypes were significantly higher than the values in subjects with Tt genotype and BB or Bb genotype, respectively.
  
  
  CONCLUSIONS
  Functionally significant 25(OH)D deficiency affecting BMD at the hip region is prevalent in urban Asian Indians. However, variation in BMD at the spine and forearm is related to VDR and PTH gene polymorphisms rather than to vitamin D status, at least in this hypovitaminotic D population.
authors.affiliation: Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Madhava Rao
authors.initials: MR
authors.lastname: Vupputuri
authors.forename: Ravinder
authors.initials: R
authors.lastname: Goswami
authors.forename: Nandita
authors.initials: N
authors.lastname: Gupta
authors.forename: Debarti
authors.initials: D
authors.lastname: Ray
authors.forename: Nikhil
authors.initials: N
authors.lastname: Tandon
authors.forename: Neeta
authors.initials: N
authors.lastname: Kumar
mesh_terms: D000328:Adult; D015992:Body Mass Index; D005260:Female; D005838:Genotype; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D010281:Parathyroid Hormone / Q000235:genetics*; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D015995:Prevalence; D018167:Receptors, Calcitriol / Q000235:genetics*; D014505:Urban Population; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology*
chemical_list: D010281:Parathyroid Hormone; D018167:Receptors, Calcitriol; D014807:Vitamin D; C104450:25-hydroxyvitamin D