Inclusion Criteria:  Patients 65 years of age and older. Patients for whom cardiac surgery will be performed on a scheduled basis. Patients able to move without the help of others except for an aid: a stick, a walker. Patients who speak and understand Lithuanian perfectly. Patients who have read the informed consent form and confirmed their consent to participate in the study in writing.  Exclusion Criteria:  Patiens younger than 65 years. No written consent of a person to participate in a biomedical research has been obtained; Patients with a history of mental illness or central nervous system disorders that interfere with the perception and proper assessment of their health and the meaning and content of the questionnaire / tasks. Patients with amputated lower extremities. Patients with hepatic insufficiency, one or more of viral hepatitis. It is not possible to perform a qualitative physical examination for other reasons (hearing, vision, etc.) Allergy to B vitamins.