Publication date: Sep 18, 2025
“Long COVID” refers to a condition in which individuals continue to experience persistent signs and symptoms even after recovering from the initial COVID-19 infection. Signs and symptoms that persist can affect multiple organs in the body. Vitamin D is an essential nutrient that plays a crucial role, particularly in the immune system, and may be linked to the development of long COVID. The study aimed to investigate the association between vitamin D levels and the prevalence of long COVID signs and symptoms in COVID-19 patients. The study enrolled 170 COVID-19 patients with mild signs and symptoms and confirmed COVID-Ag or RT-PCR tests. The subjects were aged 18-59 years. All patients had 25(OH)D levels measured within 60 days of COVID-19 diagnosis and had been followed for at least 3 months post-infection. Data collected included demographic characteristics, serum 25(OH)D levels, and self-reported long COVID signs and symptoms questionnaire responses. The study results indicated a female-to-male ratio of 1. 1:1 and a mean age of 45. 87 +/- 8. 65 years; of these, 62. 4% received three doses of the COVID-19 vaccine, and 64. 7% developed long COVID. The most prevalent signs and symptoms were respiratory (55. 3%), skin (50. 6%), and general (39. 4%). The median blood vitamin D level was 22. 96 ng/mL, with 41. 2% of subjects having insufficient levels, 30. 6% having deficient levels, and 28. 2% having sufficient levels. Patients with long COVID had significantly lower vitamin D levels compared with those without long COVID (21. 52 ng/mL vs. 25. 46 ng/mL; p
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Semantics
| Type | Source | Name |
|---|---|---|
| drug | DRUGBANK | Vitamin D |
| disease | MESH | Long COVID |
| disease | MESH | COVID-19 |
| disease | MESH | infection |
| disease | IDO | role |
| pathway | REACTOME | Immune System |
| disease | IDO | blood |
| disease | MESH | vitamin D deficiency |
| drug | DRUGBANK | Coenzyme M |
| disease | MESH | vitamin deficiency |
| disease | IDO | production |
| disease | MESH | Sequelae |
| disease | IDO | history |
| disease | MESH | syndrome |
| disease | MESH | chest pain |
| disease | MESH | smell loss |
| disease | MESH | hair loss |
| disease | MESH | joint pain |
| disease | MESH | anxiety |
| disease | MESH | depression |
| pathway | REACTOME | Vitamins |
| drug | DRUGBANK | Ribostamycin |
| disease | IDO | protein |