As we have often discussed, proponents of so-called alternative medicine (SCAM), have an unfortunate tendency to mislead the public about vitamins and other supplements. Consequently, there is much uncertainty in many people’s minds. It is, therefore, all the more important to highlight new information that might counter this phenomenon.
This study tested whether high-dose zinc and/or high-dose ascorbic acid reduce the severity or duration of symptoms compared with usual care among ambulatory patients with SARS-CoV-2 infection. It was designed as a multicenter, single health system randomized clinical factorial open-label trial and enrolled 214 adult patients with a diagnosis of SARS-CoV-2 infection confirmed with a polymerase chain reaction assay who received outpatient care in sites in Ohio and Florida. The trial was conducted from April 27, 2020, to October 14, 2020.
Patients were randomized in a 1:1:1:1 allocation ratio to receive either:
- zinc gluconate (50 mg),
- ascorbic acid (8000 mg),
- both of these agents,
- standard care only.
The treatments lasted 10 days.
The primary endpoint was the number of days required to reach a 50% reduction in symptoms, including the severity of fever, cough, shortness of breath, and fatigue (rated on a 4-point scale for each symptom). Secondary endpoints included days required to reach a total symptom severity score of 0, cumulative severity score at day 5, hospitalizations, deaths, adjunctive prescribed medications, and adverse effects of the study supplements.
A total of 214 patients were randomized, with a mean (SD) age of 45.2 (14.6) years and 132 (61.7%) women. The study was stopped for a low conditional power for benefit with no significant difference among the 4 groups for the primary endpoint. Patients who received usual care without supplementation achieved a 50% reduction in symptoms at a mean (SD) of 6.7 (4.4) days compared with 5.5 (3.7) days for the ascorbic acid group, 5.9 (4.9) days for the zinc gluconate group, and 5.5 (3.4) days for the group receiving both (overall P = .45). There was no significant difference in secondary outcomes among the treatment groups.
The authors concluded that, in this randomized clinical trial of ambulatory patients diagnosed with SARS-CoV-2 infection, treatment with high-dose zinc gluconate, ascorbic acid, or a combination of the 2 supplements did not significantly decrease the duration of symptoms compared with standard of care.
This study has several limitations (and its authors are laudably frank about them):
- Its sample size is small.
- It has no placebo control group.
- It is open-label.
- Patients were not masked to which therapy they received.
The trial nevertheless adds important information about the value of using zinc or vitamin C or both in the management of COVID patients.