Zinc is a critical cofactor for enzymes involved in the regeneration and function of taste receptor cells. These cells have a high turnover rate, and zinc defic

Zinc is a critical cofactor for enzymes involved in the regeneration and function of taste receptor cells. These cells have a high turnover rate, and zinc deficiency can impair their renewal. Zinc supplementation is usually the first line of treatment in taste disturbances, especially when nerve damage is not suspect, and it's often effective. See, e.g.: https://www.sciencedirect.com/science/article/pii/S2468548821001235 https://www.sciencedirect.com/science/article/pii/S246854882... Also: https://pubmed.ncbi.nlm.nih.gov/23305423/ https://pubmed.ncbi.nlm.nih.gov/23305423/ It's possible that covid infection somehow disrupted zinc homeostasis. Taste receptor cells also express ACE2, which is what the virus tends to latch onto... I suppose a feasible mechanism -- or at least a hypothesis -- is that viral binding to ACE2 may have downregulated zinc-dependent signaling pathways (for e.g., those involving metallothioneins or zinc-finger transcription factors).