title: Reference intervals of serum calcium, ionized calcium, phosphate and alkaline phosphatase in healthy Indian school children and adolescents.
abstract: OBJECTIVE
  To develop age- and sex-specific reference interval of serum total calcium, ionized calcium, inorganic phosphates and alkaline phosphatase in healthy Indian children in the age group of 6-17 years.
  
  
  METHODS
  Subjects for this study were selected from the schools of Delhi. The final analysis included 3,327 children in the age group of 6-17 years (1707 boys; 1620 girls).
  
  
  RESULTS
  The mean, standard deviation, 5th, 25th, 50th, 75th, 90th, 95th and 97th centile values of biochemical parameters for boys and girls are presented. All these parameters were significantly higher in boys than girls except serum ionized calcium. Serum total calcium (r -0.1362, p<0.001), serum inorganic phosphate (r -0.45, p<0.001) and serum alkaline phosphatase (r -0.5587, p<0.001) have shown inverse relationship with age.
  
  
  CONCLUSIONS
  Reference interval of selected biochemical parameters for healthy Asian-Indian children in the age group of 6-17 years is presented.
authors.affiliation: Department of Endocrinology & Thyroid Research, Institute of Nuclear Medicine and Allied Sciences (INMAS), Delhi, India. marwaha_ramank@hotmail.com
authors.forename: R K
authors.initials: RK
authors.lastname: Marwaha
authors.forename: R
authors.initials: R
authors.lastname: Khadgawat
authors.forename: N
authors.initials: N
authors.lastname: Tandon
authors.forename: R
authors.initials: R
authors.lastname: Kanwar
authors.forename: A
authors.initials: A
authors.lastname: Narang
authors.forename: A
authors.initials: A
authors.lastname: Sastry
authors.forename: K
authors.initials: K
authors.lastname: Bhadra
authors.forename: M
authors.initials: M
authors.lastname: Kalaivani
mesh_terms: D000293:Adolescent; D000375:Aging / Q000097:blood; D000469:Alkaline Phosphatase / Q000097:blood*; D001827:Body Height; D001835:Body Weight; D002118:Calcium / Q000097:blood*; D002648:Child; D005260:Female; D058851:GPI-Linked Proteins / Q000097:blood; D006262:Health; D006801:Humans; D007194:India; D007527:Isoenzymes / Q000097:blood*; D008297:Male; D010710:Phosphates / Q000097:blood*; D012016:Reference Values; D012727:Sex Characteristics
chemical_list: D058851:GPI-Linked Proteins; D007527:Isoenzymes; D010710:Phosphates; D000469:Alkaline Phosphatase; C019839:alkaline phosphatase, placental; D002118:Calcium