Neurological Symptoms and Serum Vitamin B12 Levels Correlate in Covid-19 Patients

At the beginning of the COVID-19 pandemic, olfactory and gustatory changes were common, and they were associated with vitamin B12 deficiency. From early 2022 we observed post-COVID neurological symptoms that significantly worsened the patient's quality of life, and because of this, the patients were referred to primary care. The objective of our research was to evaluate the vitamin B12 deficiency correlation to post-COVID neurological symptoms. 312 patients with laboratory-confirmed COVID-19 were included in the research. All the patients suffered from self-rated symptoms such as memory problems, impaired concentration, mood changes, tingling sensation, and/or weakness of muscles. All patients either denied having these symptoms before the COVID-19 infection or claimed that having these symptoms did not affect their quality of life. Using standard enzyme-linked immunosorbent assay (ELISA) serum vitamin B12 levels in the patients were measured. The study showed that 85% of patients had low levels of vitamin B12. Based on the laboratory results, patients have been prescribed a daily dose of peroral vitamin B12 therapy for 2 months. Patients with a severe deficiency were initially given the injectable form for the first ten days, followed by a switch to the tablet form. Upon completing the treatment, all patients reported a significant reduction or complete disappearance of their symptoms. Based on our study we recommend the monitoring of vitamin B12 levels in patients presenting with neurological symptoms developed after COVID-19 infection. The study also showed that oral supplementation alone may not be sufficient to achieve the desirable level of vitamin B12 in all patients.