The ongoing pandemic of SARS CoV-2 virus is calling for effective preventive and theraputic interventions. Vitamin D has been shown to play immunemodulatory functions in human. Low vitamin D levels have been linked to increased susciptability to infections especially the acute respiratory infections. This randomised controlled study aims to explore the effect of vitamin D administration on the outcome of SARS- CoV2 virus

Background: Coronavirus disease COVID-19 is an ongoing pandemic and is causing avoidable fatalities worldwide. Vitamin D plays an essential role in the immune system. Vitamin D interferes with the majority of the immune systems cells such as macrophages, B and T lymphocytes, neutrophils and dendritic cells. We aim to find whether supplementation of vitamin D deficient diabetes with a single intramuscular cholecalciferol injection could improve the prognosis of those patients.

Patients and Methods: This was a placebo controlled randomized prospective study, included cohorts of 40 diabetes elderly patients who got infected with SARS-CoV-2 compared with 16 elderly diabetes patients matched of the same age group who got infected with SARS-CoV-2 but given a placebo instead intramuscularly were used as a control. Clinical, laboratory, treatment, and outcome data were recorded after six weeks of follow up especially ICU admissions and fate of COVID-19 disease.Vitamin D was given as a single intramuscular injection during period of the study.

Inclusion Criteria:

- Elderly type II diabetes adult with age more than 60 years males and females having deficient serum vitamin D levels (less than 25 ng/ml).

Diabetes patients recruited to the control group were only included in the study if not known to have cholecalciferol supplementation within last 6 weeks. All elderly vitamin D deficient diabetes patients were diagnosed with COVID-19 when throat-swab specimens for SARS-CoV-2 PCR were positive.

Exclusion Criteria:

• patients with known history of renal stones, diagnosis of hypercalcemia with the past year, baseline serum total calcium more than 10mg/dl, established diagnosis associated with increase the risk of hypercalcemia (e.g. metastatic cancer, sarcoidosis, multiple myeloma, primary hyperparathyroidism), and current vitamin D supplementation

Moreover, other exclusion criteria included those with known malignancy, with organ transplant, and those with known chronic autoimmune diseases and lastly those on systemic steroid for any cause