The human body is capable of producing vitamin D through skin synthesis. However, research has shown that even high exposure to sunlight may be insufficient and may require supplementation, especially in the winter months. Most adults, particularly older individuals, have problems with vitamin D deficiency.
The first symptom of deficiency is chronic fatigue, limb pain, muscle cramps, and increased susceptibility to infections.
Vitamin D may also play an important role in the pathogenesis of Hashimoto's disease. Previous studies have shown a higher frequency of vitamin D deficiency in patients with Hashimoto's disease compared to healthy individuals. The degree of disease advancement may affect the concentration of 25-hydroxycholecalciferol in serum. Furthermore, a negative correlation was observed between serum 25(OH)D levels and the level of anti-thyroid antibodies. Additionally, vitamin D supplementation appears to be effective in reducing the level of anti-thyroid peroxidase (TPO) antibodies in both deficient and normal vitamin D concentration patients. However, further research is necessary to determine the exact impact of vitamin D supplementation on Hashimoto's disease.
Vitamin D is a factor that plays a significant role in the calcium-phosphate economy. It affects bone metabolism and also has modulating and anti-inflammatory effects. A beneficial effect of vitamin D has been observed in diseases associated with excessive activation of Th1 lymphocytes, such as multiple sclerosis, rheumatoid arthritis, non-specific inflammatory bowel disease, type 1 diabetes, and psoriasis.
Researchers' opinions on vitamin D deficiency in allergic diseases still cause controversy. However, due to the wide range of vitamin D activity, this view seems simplified. In previous studies, a beneficial effect on the course of allergic diseases was observed, although the role of vitamin D in their pathogenesis has not yet been explained. Based on the latest research and knowledge of the mechanisms of vitamin D action on individual elements of the immune system, the effect of vitamin D on the course of selected allergic diseases, such as allergic asthma, atopic dermatitis, and allergic rhinitis, including the possibility of specific allergen immunotherapy, has been presented.
Vitamin D and its active analogs play a significant role in maintaining calcium-phosphate homeostasis. Vitamin D deficiency may be a consequence of inadequate supply through diet, impaired intestinal absorption, inadequate skin exposure to ultraviolet radiation, or liver and kidney failure. The consequences of mineral metabolism disorders, particularly vitamin D deficiency, are osteoporosis, exacerbation of cardiovascular disease, impairment of the immune system, and increased morbidity and mortality in patients with end-stage renal failure. These abnormalities are common in patients with chronic kidney disease.
Recent clinical studies have shown that vitamin D supplementation in patients with its deficiency contributes to a reduction in the frequency of bone disorders and cardiovascular incidents.
Recent research has highlighted the importance of vitamin D not only in bone metabolism, but also in immune and anti-tumor processes. Common vitamin D deficiency is associated with serious health consequences, such as increased mortality and morbidity due to autoimmune and neoplastic diseases. Currently, modification of the range of serum vitamin D concentrations and revision of its nutritional and pharmacological recommendations are proposed. Additionally, the discovery of the vitamin D receptor (VDR) has allowed us to understand its impact on other organs. Among all the functions that vitamin D performs in the human body, its influence on bone metabolism and calcium homeostasis is the most well-known. The discovery of the VDR receptor has led to research on its role in other systems and organs of the body. Today, it is known that vitamin D can affect not only the skeletal system, but also is related to gastrointestinal, respiratory and cardiovascular diseases, the development of certain cancers, and the occurrence of autoimmune and allergic diseases.
The VDR receptor is not only found in bone cells, but also in most extracellular cells, including renal tubular cells, intestinal epithelium, pancreatic cells, vascular walls and the heart, as well as in the brain, adrenal glands, muscles, mammary and prostate glands. In addition, it is present in practically all cells of the immune system. Such widespread presence of the VDR receptor determines the pleiotropic action of vitamin D3.
New properties of vitamin D have also been explained in the scientific literature, demonstrating its preventive action and possible application in the treatment of many diseases.
Source: K. Murlikiewicz, A. Zawiasa, M. Nowicki- Vitamin D - a panacea in nephrology and beyond. M. Jamka, M. Ruchał, J. Walkowiak - Vitamin D and Hashimoto's disease. B. Grygiel-Górniak, M. Puszczewicz - Vitamin D - a new perspective in medicine and rheumatology K.Okręglicka, K.Wiśniewska - Significance and role of vitamin D receptor gene polymorphism https://www.wspolczesnadietetyka.pl/nutrigenetyka