Vitamin D as a Multiple Player Under the Physiological and Pathological Conditions and in Diabetic Nephropathy in Children

Abstract

Vitamin D deficiency is known to be a great problem worldwide. Vitamin D plays essential role in calcium and bone metabolism. Recently data about the role of vitamin D deficiency in pathogenesis of diabetes, diabetes complications, and cardiovascular disease published. The vitamin D receptors presented in all cell types. In vitro and in vivo studies show their role in transcription of multiple genes. This function is not dependent on calcium homeostasis. These effects provide anti-proliferative, immunomodulatory, angiogenic changes; inhibition of the renin-angiotensin-aldosterone system, and neurotrophic factor expression. Diabetic nephropathy (DN) is a dangerous kidney-related complication of type 1 diabetes. DN is an important cause of end-stage kidney disease in the world. DN characterizes by presence of albuminuria, which in turn causes renal disease progression and cardiovascular complications. Main pathological processes associated with DN are the following: kidney hemodynamics changes, oxidative stress, inflammation, hypoxia, renin-angiotensin-aldosterone system (RAAS) activation. All mentioned above changes accompanied by fibrosis. The aim of the study was to do the overview of the literature dealing with physiological and pathological effects of Vitamin D. Own data dealing with the level of hypoxic disorders, condition of apoptosis controlling system and Vitamin D3 levels in children with diabetic nephropathy discussed. Thus, our results show that children with signs of DN have high level of cellular hypoxia and apoptosis, as one of the key mechanisms of kidney damage in DN. All these events are parallel in development with Vitamin D3 deficiency. Number of papers hypothesize about the role of vitamin D in the long-term complications of diabetes. It is also suggested that Vitamin D deficiency may enhance the symptoms of DN. It’s not studied if administration of vitamin D may prevent pathogenic processes related to DN progression. Finally, large well-designed randomized controlled trials of vitamin D supplementation in pediatric cohort with DN need to be done.