Effect of Vitamin D on Human Asymmetric Dimethylarginine in a Pediatric Population: A Connection between Vitamin D, Oxidative Stress, and Inflammation

in calcium and phosphorus regulation, research has increasingly recognized its involvement in various other physiological IntroductIonVitamin D is a fat-soluble vitamin, which is considered as a nutrient and also acts as a secosteroid hormone.It plays an important role in regulating calcium concentration by increasing calcium absorption, bone resorption, and decreasing renal calcium and phosphate excretion in the body.Vitamin D is obtained by the body in two primary forms: Cholecalciferol (D3), which is synthesized in the skin upon exposure to sunlight, and ergocalciferol (D2), which is derived from dietary sources.Once absorbed or synthesized, both forms of vitamin D undergo an initial hydroxylation in the liver, converting them to 25-hydroxyvitamin D [25(OH)D], also known as calcidiol, which serves as the main circulating storage form of the vitamin.Subsequently, 25(OH)D is further hydroxylated in the kidneys to produce 1,25-dihydroxyvitamin D [1,25(OH) 2 D] or calcitriol, the active form of vitamin D. Calcitriol is essential for regulating calcium and phosphate homeostasis and has various roles in maintaining bone health, cellular growth, and modulating immune function.1 Vitamin D deficiency is the main cause of rickets in children and osteomalacia in adults.Factors such as sunshine exposure, obesity, physical activity, urbanization, and dietary habits determine the status of vitamin D in a population. 2 Beyond its role