Currently, vitamin D deficiency has become a common condition in many people all over the world. It is wide

spread in different countries including sunny ones. Moreover, a significant number of patients with chronic

inflammatory diseases and autoimmune disorders are deficient or insufficient in vitamin D. Purpose of study

– To evaluate the incidence of vitamin D deficiency in patients with recurrent and chronic inflammatory

diseases and autoimmune disorders. A retrospective analysis of 59 patient’s electronic medical cards with

recurrent and chronic inflammatory and autoimmune diseases has been applied for revealing vitamin D

insufficiency frequency. We have found that almost all of the patients had non-optimal levels of vitamin D.

The study has concluded that Vitamin D deficiency and insufficiency are common in patients with recurrent

and chronic inflammatory diseases of the respiratory system, urinary tract, and inflammatory polyarthropaties

as well as in patients with autoimmune disorders. This demonstrates the necessity of testing and restoring the

level of vitamin D in these groups of patients.