Vitamin D status is related to severity at onset of diabetes and worse glycemic control.

Objectives Our aim is to evaluate whether 25-hydroxyvitamin D at onset of type 1 diabetes mellitus (T1DM) would influence analytical variables of worse prognosis of the disease at the beginning and after one year of development. Methods A retrospective study of pediatric patients (0-14 years) diagnosed with T1DM with initial measurements of 25-hydroxyvitamin D was performed at Son Espases Hospital, between March 2012 and April 2019 (n=67). Results Vitamin D insufficiency was related to age, glycosylated hemoglobin, and creatinine. An improvement in glycosylated hemoglobin was found in subjects whose baseline serum 25(OH)D was >30 ng/mL. Bivariate correlation analysis adjusted by age showed a significantly positive correlation of vitamin D with pH (r=0.279), bicarbonate (r=0.338), and free levothyroxine (r=0.293). Independent variables associated with vitamin D insufficiency were age (odds ratio [OR]=1.2) and winter season (OR=10.52). Conclusion Hypovitaminosis D is related to biochemical variables showing greater severity and higher glycosylated hemoglobin at diagnosis: higher creatinine, lower free levothyroxine, pH, and bicarbonate. Unsupplemented patients with baseline deficiency showed persistently worse glycemic control vs. those with baseline repletion.