Issues of diagnostics and treatment of vitamin D deficiency in older patients

Abstract

Vitamin D is a fat-soluble compound that a person obtains from food or synthesizes independently when the skin is exposed to sunlight. Vitamin D metabolism is modulated by various intrinsic and extrinsic factors, including genetic polymorphism, skin type (pigmentation), age, health, season, latitude, clothing, and diet. Some of them are modifiable, i.e., they can be controlled by humans. To assess the vitamin D level in the body, the recommendation was to determine the concentration of total 25(OH)D in the blood serum, the main circulating form, which reflects both the intake of vitamin D from food and native preparations and the synthesized vitamin D in the skin under the influence of ultraviolet irradiation. This study focused on the diagnosis and treatment of vitamin D deficiency in older patients. The age-related problem is associated with a more frequent history of surgery and chronic diseases requiring drug therapy, which in turn can affect the metabolism of this vitamin. Vitamin D deficiency in older people requires constant and long-term use of cholecalciferol; however, the risks of drug interactions and polypharmacy should not be overlooked. The diagnosis and treatment of vitamin D deficiency in older people should consider all the characteristics of this group. Moreover, this study presents the features of vitamin D metabolism in older people, nosologies predisposing to the development of vitamin D deficiency, methods for diagnosing and correcting vitamin D deficiency, and relationship between severe COVID-19 and vitamin D levels. Further study of possible drug interactions, additional effects of vitamin D, and its contribution to comorbidities is warranted.