Background: The aftermath of the COVID-19 pandemic has given rise to a diverse array of challenges impacting multiple facets of daily life. Vitamin D, renowned for its immunomodulatory properties, has been implicated in mitigating viral infections, preventing complications, and arresting the progression of chronic conditions. Objectives: To evaluate the effect of vitamin D supplementation in ameliorating post-COVID-19 symptoms. Methods: A randomized-controlled clinical trial was conducted on 111 post-COVID-19 patients recruited from the post-COVID-19 Outpatient Clinic at Menoufia University Hospital between October 2021 and June 2022. Before the intervention, baseline data, detailed medical history, and clinical assessments were collected. Additionally, serum vitamin D levels were measured in all patients. Subsequently, participants were randomly assigned to a 2-month supplementation regimen, either the vitamin D group, receiving a daily oral dose of vitamin D (2000 IU/tablet), or a visually identical placebo. Results: Among patients with insufficient vitamin D levels, approximately 75.7% experienced more than 3 post-COVID-19 symptoms. A notable negative correlation was observed between the frequency of post-COVID-19 symptoms and vitamin D levels (R=-0.505, P-value< 0.001). After a 2-month intervention with vitamin D, compared to the placebo, there was a significant improvement in various symptoms such as fatigue, sleep disturbance, lack of concentration, cough, myalgia, arthralgia, and hair loss (P-value<0.001).
Conclusion: This study establishes a significant connection between vitamin D deficiency and persistent post-COVID-19 symptoms, emphasizing the beneficial role of vitamin D in relieving symptoms. The findings support the routine assessment of vitamin D levels in individuals with post-COVID-19 symptoms, with a recommendation for vitamin D supplementation in cases of deficiency.
Keywords: COVID; Deficiency; Improvement; Vitamin D