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.

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.