Effect of vitamin D supplementation on lipid profile in vitamin D-deficient children with type 1 diabetes and dyslipidemia

Background: Vitamin D (VD) was suggested to have both direct and indirect effects on modifying lipid profile in patients with diabetes through its regulatory action that increases the activity of lipoprotein lipase in adiposity. Objectives: To detect the relationship between serum 25-hydroxyvitamin D (25OHD) and lipid profiles in dyslipidemic T1D patients and study the effect of VD supplementation on lipid profiles of VD-deficient T1D patients. Methods: Fifty patients with T1D (for >2 years) and dyslipidemia were included. 25OHD was assessed and patients were divided accordingly into 2 groups: VD sufficiency (>30 ng/mL) and VD deficiency (VDD) or insufficiency (<29 ng/mL) who were allocated to VD3 supplementation for 4 months, then lipid profile was reevaluated in both groups. Results: Thirty patients had VDD, while 20 patients had VD sufficiency. There was no significant correlation between 25OHD and different study parameters (p > 0.05). A significant difference was found among both groups in the family history of coronary heart disease (p = 0.036) and free tetraiodothyronine 4 (p = 0.035). After 4 months of VD supplementation in VDD group, the mean difference (at 0 and 4 months) in low-density lipoproteins (LDL) and hemoglobin A1c (HbA1c) was statistically significant (p = 0.02 and 0.04 respectively) between both groups. The mean basal LDL was 126.91 mg/dL in VDD group that improved to 117.13 mg/dL after 4 months of VD therapy with a mean difference of-9.7 mg/dL compared to a mean difference of-2 mg/dL in VD sufficiency group. Conclusions: VDD was highly prevalent in patients with T1D. There was no significant correlation between 25OHD levels and lipid profile in patients with T1D. VD supplementation for 4 months had a significant lowering effect on LDL and HbA1c.