Effectiveness of the vitamin D in the glucose metabolism disorders and thyroid dysfunction correction in the elderly people

Due to population aging and an increasing prevalence of metabolic and autoimmune diseases in elderly people, interest in potential modulating factors that affect the course and outcomes of endocrine disorders is increasing. Vitamin D can be considered a potential factor in the pathogenesis of endocrine disorders, such as insulin resistance and autoimmune thyroid diseases. Vitamin D deficiency is of particular importance in elderly patients with a high prevalence of type 2 diabetes mellitus and subclinical hypothyroidism. Objective. To evaluate the effectiveness of vitamin D in the treatment of carbohydrate metabolism and thyroid function disorders in elderly patients. Materials and methods. A review of clinical studies, meta-analyses, and systematic reviews available in the PubMed, Scopus, Web of Science, Google Scholar, and RSCI databases was performed. Included were studies of patients aged 60 years or older evaluating the effects of vitamin D on carbohydrate metabolism, thyroid function, and the incidence of related disorders. Results. In patients with vitamin D deficiency, calcidiol levels were significantly associated with fasting glucose, insulin, and glycated hemoglobin. The most pronounced effects were observed in patients with≥24 weeks of therapy and in those with baseline calcidiol deficiency. There were no statistically significant clinical benefits in individuals with a normal vitamin D baseline level. The results of studies on the prevention of primary hypothyroidism and type 2 diabetes mellitus were controversial. The effectiveness of therapy varied by age, sex, body mass index, dose, and duration of vitamin D intake. Conclusions. The findings support the potential clinical relevance of vitamin D as adjunctive therapy for endocrine disorders in elderly patients. However, the high variability in results and limited evidence in populations with a baseline normal vitamin D level require further randomized studies with a long follow-up period and stratification by baseline biomarkers.