Background: The relationship between 25 hydroxy cholecalciferol (25OHD) deficiency and autoimmune diseases including type I diabetes (T1D) is an ongoing area of research interest. Furthermore, vitamin D seems to affect β cells through calcium regulation, as insulin release is a calcium-dependent process. The aim of the study was to screen for (25OHD) deficiency in children with clinical onset of T1D and study the correlation between its serum levels and anti-glutamic acid decarboxylase antibody titre and serum C-peptide levels.
Methods: A cross-sectional study included 102 children with new-onset T1D. Serum levels of 25OHD, fasting and postprandial C-peptide and anti-GAD 65 antibody were assessed.
Results: This study included 52 females and 50 males with newly-diagnosed T1D, with a mean age of 8.8±3.1 years. Serum 25OHD level ranged from 4.2 to 40.6 ng/mL with a mean of 15.5±6.2 ng/mL. Among the studied patients, 74.5% were vitamin D deficient and 23.5 were vitamin D insufficient. 25OHD status had significant negative correlation with anti-GAD 65 titre (r = - 0.31, P = 0.002), while it correlated positively with serum levels of fasting C peptide (r = 0.29, P = 0.002) and postprandial C-peptide (r = 0.27, P = 0.005).
Conclusions: Vitamin D deficiency and insufficiency was highly prevalent in Egyptian children with new-onset T1DM. In agreement with the hypothesis that an inadequate vitamin D trigger autoimmunity, vitamin D level in the studied cohort was negatively correlated with anti-GAD antibody levels. Thus, it would be fundamental to study the effect of vitamin D supplementation in prediabetic state to slow the autoimmune cascade.
Keywords: type 1 diabetes; 25OHD; vitamin D supplementation; anti-GAD 65; C-peptide
19 - 21 Sep 2019
European Society for Paediatric Endocrinology