title: The association between ketoacidosis and 25(OH)-vitamin D levels at presentation in children with type 1 diabetes mellitus.
abstract: BACKGROUND
  There is considerable evidence supporting the role of vitamin D deficiency in the pathogenesis of type 1 diabetes mellitus (T1DM). Vitamin D deficiency is also associated with impairment of insulin synthesis and secretion. There have been no formal studies looking at the relationship between 25(OH)-vitamin D(3) and the severity of diabetic ketoacidosis (DKA) in children at presentation with T1DM.
  
  
  OBJECTIVE
  To determine the relationship between measured 25(OH)-vitamin D(3) levels and the degree of acidosis in children at diagnosis with T1DM.
  
  
  METHODS
  Children presenting with new-onset T1DM at a tertiary children's hospital.
  
  
  METHODS
  25(OH)-vitamin D(3) and bicarbonate levels were measured in children at presentation with newly diagnosed T1DM. Those with suboptimal 25(OH)-vitamin D(3) levels (<50 nmol/L) had repeat measurements performed without interim vitamin D supplementation.
  
  
  RESULTS
  Fourteen of the 64 children had low 25(OH)-vitamin D(3) levels at presentation, and 12 of these had low bicarbonate levels (<18 mmol/L) (p = 0.001). Bicarbonate explained 20% of the variation in vitamin D level at presentation (partial r(2) = 0.20, p < 0.001) and ethnic background a further 10% (partial r(2) = 0.10, p = 0.002). The levels of 25(OH)-vitamin D(3) increased in 10 of the 11 children with resolution of the acidosis.
  
  
  CONCLUSIONS
  Acid-base status should be considered when interpreting 25(OH)-vitamin D(3) levels in patients with recently diagnosed T1DM. Acidosis may alter vitamin D metabolism, or alternatively, low vitamin D may contribute to a child's risk of presenting with DKA.
authors.affiliation: Department of Paediatric Endocrinology and Diabetes, Mater Children's Hospital, Brisbane, QLD, Australia. tony.huynh@mater.org.au
authors.forename: Tony
authors.initials: T
authors.lastname: Huynh
authors.forename: Ristan M
authors.initials: RM
authors.lastname: Greer
authors.forename: Ohn
authors.initials: O
authors.lastname: Nyunt
authors.forename: Francis
authors.initials: F
authors.lastname: Bowling
authors.forename: David
authors.initials: D
authors.lastname: Cowley
authors.forename: Gary M
authors.initials: GM
authors.lastname: Leong
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Cotterill
authors.forename: Mark
authors.initials: M
authors.lastname: Harris