title: A pilot interventional study to evaluate the impact of cholecalciferol treatment on HbA1c in type 1 diabetes (T1D).
abstract: BACKGROUND
  Higher 25(OH)D3 levels are associated with lower HbA1c, but there are limited UK interventional trials assessing the effect of cholecalciferol on HbA1c.
  
  
  OBJECTIVE
  (1) To assess the baseline 25(OH)D3 status in a Manchester cohort of children with type 1 diabetes (T1D). (2) To determine the effect of cholecalciferol administration on HbA1c.
  
  
  METHODS
  Children with T1D attending routine clinic appointments over three months in late winter/early spring had blood samples taken with consent. Participants with a 25(OH)D3 level <50 nmol/L were treated with a one-off cholecalciferol dose of 100,000 (2-10 years) or 160,000 (>10 years) units. HbA1c levels before and after treatment were recorded.
  
  
  RESULTS
  Vitamin D levels were obtained from 51 children. 35 were Caucasian, 11 South Asian and 5 from other ethnic groups. 42 were vitamin D deficient, but 2 were excluded from the analysis. All South Asian children were vitamin D deficient, with mean 25(OH)D3 of 28 nmol/L. In Caucasians, there was a negative relationship between baseline 25(OH)D3 level and HbA1c (r= -0.484,P< 0.01). In treated participants, there was no significant difference in mean HbA1c at 3 months (t= 1.010,P= 0.328) or at 1 year (t= -1.173,P= 0.248) before and after treatment. One-way ANCOVA, controlling for age, gender, ethnicity, BMI and diabetes duration showed no difference in Δ HbA1c level.
  
  
  CONCLUSIONS
  We report important findings at baseline, but in children treated with a stat dose of cholecalciferol, there was no effect on HbA1c. Further studies with larger sample sizes and using maintenance therapy are required.
authors.affiliation: Division of Developmental Biology & MedicineSchool of Medical Sciences, Faculty of Biology, Medicine & Health, University of Manchester, Manchester, UK.
authors.forename: R
authors.initials: R
authors.lastname: Perchard
authors.affiliation: Division of Developmental Biology & MedicineSchool of Medical Sciences, Faculty of Biology, Medicine & Health, University of Manchester, Manchester, UK.
authors.forename: L
authors.initials: L
authors.lastname: Magee
authors.affiliation: Division of Developmental Biology & MedicineSchool of Medical Sciences, Faculty of Biology, Medicine & Health, University of Manchester, Manchester, UK.
authors.forename: A
authors.initials: A
authors.lastname: Whatmore
authors.affiliation: Department of BiochemistryCentral Manchester University Hospitals NHS Foundation Trust, Manchester, UK.
authors.forename: F
authors.initials: F
authors.lastname: Ivison
authors.affiliation: Division of Developmental Biology & MedicineSchool of Medical Sciences, Faculty of Biology, Medicine & Health, University of Manchester, Manchester, UK.|Department of Paediatric EndocrinologyRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester, UK.
authors.forename: P
authors.initials: P
authors.lastname: Murray
authors.affiliation: Division of Developmental Biology & MedicineSchool of Medical Sciences, Faculty of Biology, Medicine & Health, University of Manchester, Manchester, UK.
authors.forename: A
authors.initials: A
authors.lastname: Stevens
authors.affiliation: Department of Paediatric EndocrinologyRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester, UK.
authors.forename: M Z
authors.initials: MZ
authors.lastname: Mughal
authors.affiliation: Department of Paediatric EndocrinologyRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester, UK.
authors.forename: S
authors.initials: S
authors.lastname: Ehtisham
authors.affiliation: Department of Paediatric EndocrinologyRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester, UK.
authors.forename: J
authors.initials: J
authors.lastname: Campbell
authors.affiliation: Department of Paediatric EndocrinologyRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester, UK.
authors.forename: S
authors.initials: S
authors.lastname: Ainsworth
authors.affiliation: Department of BiochemistryCentral Manchester University Hospitals NHS Foundation Trust, Manchester, UK.
authors.forename: M
authors.initials: M
authors.lastname: Marshall
authors.affiliation: Department of General PaediatricsRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester, UK.
authors.forename: M
authors.initials: M
authors.lastname: Bone
authors.affiliation: Department of General PaediatricsRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester, UK.
authors.forename: I
authors.initials: I
authors.lastname: Doughty
authors.affiliation: Division of Developmental Biology & MedicineSchool of Medical Sciences, Faculty of Biology, Medicine & Health, University of Manchester, Manchester, UK peter.clayton@manchester.ac.uk.|Department of Paediatric EndocrinologyRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester, UK.
authors.forename: P E
authors.initials: PE
authors.lastname: Clayton
keywords: HbA1c; bone; diabetes; paediatric endocrinology; vitamin D