Title: Multifunctional properties of Vitamin D

Abstract:

Background: Recent evidence for the nonskeletal effects of vitamin D, coupled with recognition that vitamin D deficiency is
common. Vitamin D deficiency identified as a common metabolic/endocrine disorder worldwide. Because many countries have a relatively low supply of foods rich in vitamin D and inadequate exposure to natural ultraviolet B (UVB) radiation from sunlight, an important proportion of the global population is at risk of vitamin D deficiency. Vitamin D deficiency and insufficiency affect almost 1 billion people worldwide.
Material and Methods: Literature data concerning the Vitamin D role under the physiological and pathological conditions done. In own study 36 children with type 1 diabetes (T1D) (aged 6 to 17 years) hospitalized in Endocrinology unit of Children Clinical Hospital ?6 (Kyiv, Ukraine) included. Vitamin D3 levels studied using ELISA assay and commercially available kit (Vitamin D3 (human) ELISA kit (BioVision, USA). Results processed using STATISTICA 6.0 and nonparametric statistical method (Mann-Whitney test).
Results: Vitamin D is a fat-soluble prohormone, synthesized in our epidermal cells following exposure to sunlight. Vitamin
D has essential roles in the metabolism of calcium and phosphorus and is thus critical for bone growth and bone mineral metabolism. Vitamin D deficiency is known to cause two metabolic bone diseases, rickets (in children) and osteomalacia (in adults).It has been considered a hormone rather than a vitamin, vitamin D has receptors on virtually every cell in the human body. Vitamin D also functions in the regulation of the immune system and in the proliferation and differentiation of numerous cell types. Over the past two decades, laboratory and epidemiological studies have also suggested that low vitamin D status may be associated with a variety of health risks, including respiratory illnesses (infections and asthma), adverse pregnancy outcomes, and chronic diseases of adulthood, such as osteoporosis and cardiovascular disease. The serum 25-hydroxyvitamin D levels considered as indicator of body’s vitamin D stores. Crucial role in Vitamin D metabolism plays kidney and being a target to its changed levels as well. Vitamin D3 attenuates kidney injury by suppressing fibrosis, inflammation, and apoptosis, by inhibiting multiple pathways known to play a role in kidney injury, including the renin-angiotensin-aldosterone system (RAAS), the nuclear factor-κB (NF-κB), the transforming growth factor-β (TGF-β)/ Smad. Study by Edwards M.H. et al., (2019) show results on vitamin D deficiency worldwide. Severe deficiency seems to be most common in the Middle East and South Asia with high prevalence of rickets in these areas. In areas, such as Africa and Asia, data are not available on the prevalence of vitamin D deficiency. In regions such as Scandinavia, dietary supplements appear to have been effective in reducing the prevalence of deficiency.The food fortification used in North America has successfully increased the mean serum levels in the population. In our study normal level, insufficiency and deficiency of the Vitamin D defined as - ≥ 30 ng/mL, 21-29 ng/mL and ≤ 20 ng/ mL, respectively. We show that the most prominent Vitamin D3 deficiency detected in the group of patients with diabetic nephropathy (DN). In control group Vitamin D3 was detected at level 35.68 ± 1.56 ng/mL, in patients with T1D – 32.37 ± 5.1 ng/mL, in patients with DN – 19.39 ± 1.76 ng/mL (?<0.01 as compared to control group).
Conclusion: Despite the numerous reports of the vitamin D association with a number of development, disease treatment
and health maintenance, vitamin D deficiency is common. Vitamin D – a multiple player and has an important role in
pathogenesis rickets, kidney diseases and endocrine disorders, i.e. diabetic nephropathy worldwide. Own data show the prominent deficiency of Vitamin D in T1D patients and patients with DN. Further investigations in this field are necessary in order to find an adequate disease prevention and treatment.