Background: Vitamin D deficiency can increase susceptibility to viral infections such as Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2). The
current study has two aims; first, measuring 25-hydroxyvitamin D (25 (OH) D) concentration in a group of Moroccan health professionals, in order to determine the
prevalence of hypo-vitaminosis D and to supplement those at risk. Second, conducting a 5-month flow-up; In order to detect individuals contracting SARS-CoV-2
infection, whether or not they manifest severe respiratory symptoms, and therefore to evaluate the impact of Vitamin D supplementation on their immune system.
Methods: This is a prospective, observational study, which had been occurred at Children’s hospital of UHC Ibn Sina of Rabat. Measurement of 25-hydroxyvitamin D
was determined by ARCHITECT 25-OH VITAMIN D at the biochemistry laboratory of Ibn Sina Hospital in Rabat. After 25 (OH) D measurements, a supplementation
of cholecalciferol 100,000 IU VITD 3 was administered according to its status for each participant.
Results: Sixty-five participants were enrolled in this study; 85% were females. The average value of 25-hydroxyvitamin D in the general population was 17 ± 7 ng/
ml, with extreme values of 7 and 34 ng/ml. Ninety-two percent of the studied population presented hypo-vitaminosis D. Thirteen participants (20%) were infected
with SARS-CoV-2. Although, no cases required hospitalization or respiratory support.
Conclusion: It appears necessary to supplement individuals at risk of contracting respiratory viral infections, particularly health professionals who are on the front
line against COVID-19 pandemic.