Quote:
Previous research has shown that zinc can interfere with proteolytic processing of polyproteins in RNA viruses1, and the RNA polymerase of SARS-CoV-12. Coronaviruses frequently cause the common cold. A recent meta-analysis of 7 randomized controlled trials (RCT's) showed that zinc lozenges shortened the mean duration of the common cold by 33% (95% CI, 21-45%)3. Hospitalized COVID-19 patients taking supplemental zinc in addition to standard therapy were reported to have lower death rates4, and patients with lower zinc levels on admission had higher mortality5. We recently reported that 4 outpatient COVID-19 patients taking high dose oral zinc appear to recover shortly after initiation of zinc6.
We retrospectively reviewed consecutive cases of laboratory confirmed COVID-19 (26 cases), or CDC case definition (2 cases), who were started on zinc gluconate/citrate lozenges (23 mg of elemental zinc, 21 patients) or zinc acetate lozenges (15 mg of elemental zinc, 7 patients), at a total dosage of 2 to 2.5 mg/kg/day. Patients were instructed to place one lozenge on their tongue q2-4 hours while awake, for a minimum of 10 days. Depending on weight, patients took between 6 and 12 lozenges daily. Written or verbal consent was obtained prior to treatment. The median number of days between symptom onset and initiation of zinc was 4 days, ranging from 1 to 21 days after onset of symptoms. The mean age was 40: 17 female, 11 male, 3 Hispanic, 3 Asian, 1 African-American and 21 Caucasian. Patients were contacted daily for symptom evaluation, and for side effects.
Ten symptoms were scored according to a COVID-19 symptom checklist , categorized on a 3 point scale: 0-no symptoms,1-mild, 2-moderate, 3- severe. Fever and shortness of breath were further defined as follows: Fever 0 - 98.6, 1-  98.6-100.0, 2- 100.0 - 102.0, 3-  102.0. Shortness of breath (SOB) 1= moderate intensity exercise, 2= with walking on flat surface, 3= with any movement or at rest.
Cough, nausea/vomiting, diarrhea, sore throat, headache, muscle/body aches, fatigue and loss of smell/taste were also assessed.
All 28 patients were improved after 7 days of zinc. Symptomatic improvement began a mean of 1.6 days after zinc treatment. Patients 40 or older took an average of 2.1 days to improve vs 1.4 days for those under 40 ( p40 aged patients, vs 10 days vs 5 days), and type of zinc salt (zinc gluconate/acetate vs sulfate).The mechanisms by which zinc may help COVID-19 patients are unknown, but include direct inhibition of viral replication, improvement of mucociliar clearance of SARS-Cov-2, reduction of secondary bacterial infection, improvement of lung and kidney tissue healing after ischemia, modulation of T and B lymphocytes, and restoration of interferon-alpha production8,9. Zinc supplementation reduces the incidence of pneumonia10, and improves outcomes in diarrhea11. In addition, mild zinc deficiency is often present in those groups at highest risk from COVID-19; namely, the elderly, diabetic, obese, and hypertensive8.
In mild cases of COVID-19 about 80 % of patients begin improving after day 10; 20% worsen the second week. Zinc treated patients began improvement after 1.6 days on average. Patients older than 40 began recovery slightly later than under 40; however, the clinical outcome at 7 days was the same, and this is not the typical COVID-19 course.
A recent report12 by the CDC showed that among symptomatic adult COVID-19 outpatients, 35% were still symptomatic 2-3 weeks after testing positive. For those with SOB, one-third experienced these symptoms weeks later.
By contrast, all 9 of our patients who were SOB began improving after 2 days, and none were SOB after 7 days. Except for fatigue, all 28 patients were symptom free after 3 weeks.This study has limitations intrinsic to any retrospective review: absence of blinding and a control group. However, given the low toxicity and cost of oral zinc, it would seem prudent to begin testing of zinc in a controlled trial.