More than 4 in 10 people have increased their use of supplements since the start of the COVID-19 pandemic. Reinforce that there's still no evidence any supplement helps prevent or treat COVID-19. Not all supplements are risky. But clarify which products to avoid. Many patients swear by "immune boosters" such as colloidal silver, echinacea, green tea, selenium or vitamin C or D.
Tell patients to AVOID colloidal silver due to risk of blue-gray skin discoloration, seizures, and liver or kidney toxicity. Explain that drinking green tea seems safe. But caution about cases of liver toxicity with oral green tea extract. If patients want to take vitamins or minerals, recommend usual daily doses, higher doses may do more harm than good. Some supplements are touted for antiviral effects, such as elderberry, garlic, oleander, quercetin or zinc.
Warn that oleander is poisonous. It contains oleandrin, a cardiac glycoside similar to digoxin that may cause fatal arrhythmias. Be aware, there's not currently an oleander supplement but it's a common flowering shrub. Educate not to consume any part.
Advise not to make elderberry syrup at home. The plant has a cyanide-producing chemical that can be toxic if not cooked properly. Watch for interactions with garlic, it may increase the risk of bleeding in patients taking an anticoagulant or antiplatelet. If patients try zinc, suggest an oral form. Nasal zinc products are floating around online, but warn these may cause permanent loss of smell.
Supplements are often promoted for stress, anxiety, or sleep, such as ashwagandha, chamomile, kava, passion flower, or valerian. Advise monitoring TSH if patients on a thyroid med start ashwagandha, it may stimulate thyroid hormone production. Caution about reports of liver toxicity with kava. Continue to ask about supplement use when updating medication lists.
REFERENCES
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COVID-19 Treatment Guidelines. Adjunctive Therapy | Coronavirus Disease COVID-19. [online] Available at: https://www.covid19treatmentguidelines.nih.gov/adjunctive-therapy..
Vitamin C; https://www.covid19treatmentguidelines.nih.gov/adjunctive-therapy/vitamin-c, Vitamin D; https://www.covid19treatmentguidelines.nih.gov/adjunctive-therapy/vitamin-d AND Zinc; https://www.covid19treatmentguidelines.nih.gov/adjunctive-therapy/zincOketch-Rabah and others (2020). United States Pharmacopeia (USP) comprehensive review of the hepatotoxicity of green tea extracts. Toxicology Reports, [online] 7, pp.386–402. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7044683