On June 20, 2020 a research paper by Nurshad Ali on “Role of vitamin D in preventing of COVID-19 infection, progression and severity” was published in the Journal of Infection and Public Health (Elsevier). In that paper he observed, “Little is known about the protective factors of this infection. Therefore, preventive health measures that can reduce the risk of infection, progression and severity are desperately needed.” Thus, Ali alluded to the impact of preventive health maintenance for reducing the risk and impact of Covid 19 and not its amelioration. It is in this context the role of vitamin D has been analyzed.
He went on to add, “Several studies demonstrated the role of vitamin D in reducing the risk of acute viral respiratory tract infections and pneumonia. These include direct inhibition with viral replication or with anti-inflammatory or immunomodulatory ways. In the meta-analysis, vitamin D supplementation has been shown as safe and effective against acute respiratory tract infections. Thus, people who are at higher risk of vitamin D deficiency during this global pandemic should consider taking vitamin D supplements to maintain the circulating 25(OH)D in the optimal levels (75–125 nmol/L).” Although researchers are yet to ascertain the extent of vitamin Ds ability to fight Covid 19 yet it seems vitamin D supplementation is a safe and effective source to fight ‘acute respiratory tract infections.’
Ali observes, “Indeed, supplementation of vitamin D with doses up to 100 μg/day is safe for adults, and many expert groups now suggest supplementation in older people, although at lower levels than it. A study reported that intake of vitamin D supplement at 100–250 μg/day over 6 weeks increases the baseline serum concentration of 25(OH)D from 2 to 3 folds, respectively, without any adverse health effects.” It is interesting to note that recommendation for vitamin D dosage depends on an individual’s age (& also ethnicity). Hence, doctor’s advice becomes all the more important before taking recourse to vitamin D supplementation.
The research paper concluded that although in the randomized trials and meta-analysis, vitamin D supplementation has been shown to have protective effects against respiratory tract infections yet more randomized ‘controlled’ trials and large-scale cohort studies are still necessary to test this hypothesis.