SUN-141 Vitamin D Status and Diabetic Control in Children with Type 1 Diabetes Mellitus

Vitamin D insufficiency is common among children and adolescents, particularly among those with type 1 diabetes mellitus (T1DM). Studies of patients with type 2 diabetes mellitus (T2DM) indicated that treatment of vitamin D deficiency improved glycemic control (Nada & Shaheen, 2017). Additional studies reviewed by Peterson et al. (2014) indicated an association between vitamin D status and insulin sensitivity among obese adolescents. Other studies have investigated the effect of vitamin D on glycemic control in patients with T1DM, but little data is available about insulin sensitivity and vitamin D levels in patients with T1DM. We investigated the association between vitamin D status and diabetes control in children with T1DM. Our study was a retrospective chart review of subjects with T1DM ages 2-21 years evaluated in our pediatric diabetes clinic over the past eight years. We looked specifically at the relationship between vitamin D status, insulin requirement and Hb A1C (A1C). Inclusion criteria were: continuous insulin administration using a pump, at least two determinations of serum levels of 25-hydroxy vitamin D, frequent blood glucose (BG) monitoring and regular follow-up in our diabetes clinic. Patients were included if they had been diagnosed with diabetes for at least 11 months prior to the study, and required ≥0.49 units of insulin/kg/day. Subject demographics, A1C levels, and BG levels were recorded. Average daily insulin dose and vitamin D level determined at the corresponding clinic visit were also recorded. Data were analyzed using IBM SPSS statistical software version 24. Thirty-one patients were included in the study, ranging in age from 2.6-17.4 years old. Sixteen subjects (52%) were female and 15 subjects (48%) were male. The proportion of patients whose A1C values improved corresponded to a change in 25-hydroxyvitamin D of ≥7.5 ng/mL. An increase in the vitamin D level was associated with a statistically significant decrease in insulin requirement. Our findings suggest that optimization of vitamin D status in patients with T1DM may reduce insulin requirements and improve glycemic control. Reference: 1. Nada et al., Ther Clin Risk Manag. 2017 Jul 7;13:813-820 2. Peterson et al., Ther Adv Endocrinol Metab. 2014 Dec;5(6):166-89