Vitamin D Supplementation May Improve Outcomes in COVID-19: Study
Written By : Medha Baranwal
Medically Reviewed By : Dr. Kamal Kant Kohli
Published On 2026-03-20 15:45 GMT | Update On 2026-03-20 15:46 GMT
China: Supplementing vitamin D alongside standard treatment may reduce inflammatory markers, shorten the duration of illness, and contribute to radiographic improvement in patients with COVID-19.
These findings come from a recent study published in Endocrine, Metabolic & Immune Disorders - Drug Targets by Zhaoying Chen from the Department of Endocrinology, Weifang People’s Hospital, Shandong Second Medical University, China, and colleagues. The researchers examined whether adding vitamin D to routine therapy could improve laboratory, etiological, and imaging outcomes in patients diagnosed with COVID-19.
Vitamin D has been increasingly studied for its immunomodulatory and anti-inflammatory effects, particularly in respiratory infections. Deficiency of vitamin D has been reported in many individuals with COVID-19 and has been linked to worse disease outcomes. However, evidence regarding the clinical benefits of vitamin D supplementation in COVID-19 treatment remains limited and inconsistent. The present study aimed to explore whether vitamin D supplementation could enhance recovery and improve clinical parameters in affected patients.
For this purpose, the investigators conducted a retrospective observational study involving 300 patients with COVID-19 who were admitted between January 2022 and March 2023 at a public health center and Weifang People’s Hospital in China. Participants were divided into two groups: one group received standard treatment alone, while the other group received vitamin D supplementation in addition to standard care. Each group included 150 patients.
At baseline, the two groups were comparable in terms of demographic characteristics and laboratory indicators. Parameters such as white blood cell count, neutrophil count, lymphocyte levels, inflammatory markers including interleukin-6, C-reactive protein, procalcitonin, and serum calcium did not differ significantly between the groups. Notably, both groups initially showed lower-than-normal levels of 25-hydroxyvitamin D, indicating widespread vitamin D insufficiency among the participants.
The study led to the following findings:
- Following treatment, both groups showed improvements in inflammatory and immune markers. Levels of white blood cells, neutrophils, interleukin-6, C-reactive protein, and procalcitonin decreased, while lymphocyte counts increased.
- The magnitude of improvement was greater among patients who received Vitamin D supplementation in addition to standard therapy.
- After adjusting for potential confounding factors such as age, sex, hypertension, diabetes, and cardiovascular or cerebrovascular diseases, the supplementation group showed significantly larger increases in circulating 25-hydroxyvitamin D levels and serum calcium.
- Patients in the vitamin D group also demonstrated more pronounced improvements in neutrophil and lymphocyte counts compared with those receiving routine treatment alone.
- Inflammatory markers, particularly interleukin-6 and C-reactive protein, declined more substantially among patients receiving vitamin D supplementation.
- Clinical recovery outcomes favored the supplementation group, with faster symptom resolution and shorter time to viral clearance.
- Radiological findings also improved more noticeably in the vitamin D group, with clearer evidence of radiographic recovery.
Based on these findings, the researchers concluded that adding vitamin D supplementation to conventional therapy may help improve inflammatory profiles, accelerate recovery, and promote radiological improvement in patients with COVID-19. The authors suggest that vitamin D could serve as a supportive therapeutic strategy, although further large-scale studies may be required to confirm these findings and clarify its role in COVID-19 management.
Reference:10.2174/0118715303457486260113044737
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