Vitamin D Supplementation and Glycemic Control Improvement Among Type 1 Diabetic Children

Type 1 diabetes mellitus (T1DM) is an immune-mediated disease characterized by diminished insulin secretion due to damage to islets of Langerhans in the pancreas, which eventually results in high levels of glucose in the blood. According to World Diabetes Foundation, in Palestine, 4.4% of diabetic patients are diagnosed with T1DM, while 95.3% are diagnosed with type 2 diabetes (T2DM) (World Diabetes Foundation, 2020). Observational studies have reliably provided evidence that T1DM patients with acceptable glycemic control have higher 25(OH)D levels than T1DM with lesser glycemic control. Additionally, it has been specified by some of the research-based studies that there is a strong connection between the deficiency of vitamin D and the incidence of T1DM. In interventional studies of T1DM children and adults, repletion of vitamin D in deficient individuals improved HbA1c in a period of 12 weeks. Participants were more likely to achieve HbA1c \< 7.8% if they had higher 25(OH)D levels on week 12 than on baseline, especially if 25(OH)D levels were exceeded 51 nmol/l. According to the Food and Drug Administration (FDA), The Institute of Medicine's (IOM) recommended Upper Limit (UL) for chronic Vitamin D intake for infants (children less than 1 year of age) is 25 mcg/day (1,000 IU/d), and for children age 1 year and older the recommended UL is 50 mcg/day (2,000 IU/d) (Institute of Medicine Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, 1997). Despite a large amount of evidence from observational and experimental studies supporting the effects of vitamin D on glucose metabolism and the immune system, results from clinical studies remain inconsistent, which makes it impossible to recommend vitamin D supplementation for the treatment of T1DM. Therefore, this study aimed to investigate the status of vitamin D among T1DM children for vitamin and to examine the effects of vitamin D supplementation on glycemic control in children with T1DM. Th