What adjunctive nutritional therapies are used in the treatment of COVID-19?

Updated: Jun 25, 2021
  • Author: David J Cennimo, MD, FAAP, FACP, FIDSA, AAHIVS; Chief Editor: Michael Stuart Bronze, MD  more...
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NIH guidelines state there are insufficient evidence to recommend either for or against use of vitamins C and D, and zinc for treatment of COVID-19. The guidelines recommend against using zinc supplementation above the recommended dietary allowance. 

Vitamin and mineral supplements have been promoted for the treatment and prevention of respiratory viral infections; however, there is insufficient evidence to suggest a therapeutic role in treating COVID-19. [203]


A retrospective analysis showed lack of a causal association between zinc and survival in hospitalized patients with COVID-19. [204]

Vitamin D

A study found individuals with untreated vitamin D deficiency were nearly twice as likely to test positive for COVID-19 compared with peers with adequate vitamin D levels. Among 489 individuals, vitamin D status was categorized as likely deficient for 124 participants (25%), likely sufficient for 287 (59%), and uncertain for 78 (16%). Seventy-one participants (15%) tested positive for COVID-19. In a multivariate analysis, a positive COVID-19 test was significantly more likely in those with likely vitamin D deficiency than in those with likely sufficient vitamin D levels (relative risk [RR], 1.77; 95% CI, 1.12 - 2.81; P = .02). Testing positive for COVID-19 was also associated with increasing age up to age 50 years (RR, 1.06; P = .02) and race other than White (RR, 2.54; P = .009). [205] It is unknown if vitamin D deficiency is the specific issue, as it is also associated with various conditions that are risk factors for severe COVID-19 conditions (eg, advanced age, cardiovascular disease, diabetes mellitus). [206]  

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