Correlation of Post COVID-19 fatigue condition and Vitamin D deficiency in Thai older people

Abstract

Background: Due to the COVID-19 pandemic, more than 600 million people have been infected worldwide. Patients who recover from COVID-19 may experience long-term symptoms in 10-20% of cases, with the most common symptom being fatigue that can affect daily life, especially in older people. Studies have shown that low vitamin D levels are associated with severe COVID-19 infection and that vitamin D can suppress inflammation and help repair organs after COVID-19 infection. However, no study has yet investigated the relationship between fatigue after COVID-19 infection and the vitamin D levels. Objectives: To study the correlation of Post COVID-19 fatigue condition and Vitamin D deficiency in Thai older people. Therefore, we investigated the vitamin D levels of Thai volunteers aged 60-75 years with COVID-19 infection, divided into two groups: those diagnosed with fatigue after COVID-19 infection and those without, at Outpatient department and the Primary care unit of Phramongkutklao Hospital between January to December 2023. Results: The vitamin D levels were significantly lower in the group with fatigue after COVID-19 infection than in the control group (Mean 28.10 ng/mL and 41.30 ng/mL, p = 0.0001748, Mann-Whitney U test). There was no correlation between vitamin D levels and VAS fatigue scores in the group with fatigue (R = -0.1, p = 0.520). People with diabetes, coronary heart disease, and high blood lipids had no significant difference in the vitamin D levels compared to those without these diseases (p-value = 0.087, 0.584 and 0.136). Conclusion: This study suggests that low vitamin D levels may be a risk factor for fatigue after COVID-19 infection. Vitamin D supplementation may be an option to prevent or treat this condition but further research is needed to confirm this relationship and test the effectiveness of vitamin D in treating fatigue after COVID-19 infection.