Objective. To determine the effectiveness of treatment withmagnesium and pyridoxine nutritional supplement in chronic obstructive pulmonary disease comorbid patients.Material and methods. The study was conducted with the involvement of 63 patients who were admitted to the pulmonology and urology departments of Chernivtsi Regional Emergency Hospital — University Clinic. A comparative and statistical analysis of the parameters of the respiratory and renal function before and after the application of magnesium and pyridoxine was done with IBM SPSS Statistics v.20.Results. After treatment with combined nutritional supplement of magnesium lactate dihydrate and pyridoxine in patients with comorbid chronic obstructive pulmonary disease, chronic pyelonephritis and oxalic urolithiasis, serum level of magnesium was (1,51±0,08) mmol/l. Magnesium and pyridoxine supplement influenced glomerular filtration rate in patients in the group with comorbidity, after taking the supplement it was (90,7 ± 5,04 mL/min/1,73 m² (p <0,05), when compared with the same index in this group before the treatment, improvement of the renal function was noted.Conclusion. Nutritional intervention enables to modify the course of the polymobid diseases that is included in respiratory optimization, exacerbation control, correction of renal function.