Background. Corporate health management programs are an important tool for the timely detection of pathological conditions and their correction through in-depth medical examinations, regular medical observation, and informed interventions, which helps maintain productivity and increase the professional resources of employees. Vitamin D deficiency is one of the most common conditions worldwide and is characterized by serum 25(OH)D concentrations below 30 nm/L. This condition leads to impaired intestinal calcium absorption, leading to osteoporosis and the risk of fractures. Given the location of vitamin D receptors in many organs and tissues, deficiency can lead to a variety of extraskeletal disorders. The aim of the study was to evaluate the effectiveness of a project to monitor and correct vitamin D deficiency and insufficiency as part of a corporate employee health management program. Material and methods. The study included 997 employees of an industrial enterprise in the Kemerovo Region and Kuzbass who underwent in-depth preventive medical examinations as part of the corporate health management program. To assess vitamin D levels, the metabolite 25(OH)D was measured in serum using a chemiluminescence immunoassay on a Roche COBAS 6000 analyzer with the cobas c 702 module for clinical biochemistry testing. Study results. Adequate vitamin D levels (over 30 ng/ml) were found in 323 subjects (32.4%). Low vitamin D levels were found in 67.6% of subjects. Vitamin D deficiency (20-29 ng/ml) was detected in 365 cases (36.6%), vitamin D deficiency (10-19 ng/ml) in 280 subjects (28.1%), and severe vitamin D deficiency (less than 10 ng/ml) in 29 subjects (2.9%). Implementing a vitamin D deficiency correction project within the company's corporate employee health management program resulted in a reduction in 25(OH)D deficiency and an increase in levels from 8 to 22 ng/ml (p