Yes, it's been amazing to me how nearly everyone with continuing interest in HCQ has emphasized Zinc as an important factor, while so many studies have ignored it: neither supplementing it nor even checking enrolled patients for zinc deficiencies (which may be especially prevalent in the aged or those with known Covid comorbidities).

So I'll see, for example, some otherwise-highly-credible UCSF researchers mention a bunch of evidence they think puts the potential of HCQ to help to rest, without any mention of Zinc considerations (even in passing, or to ridicule, or to share why they don't think the link credible). But even coincident upon the very 1st discussions of HCQ as having potential, Derek Lowe shared an anecdote about how carrying-Zinc seemed essential to Chloroquine-related-compoounds' bioactivity (https://blogs.sciencemag.org/pipeline/archives/2020/03/20/ch...).

And, in many parts of the world, HCQ – as a cheap drug that, in moderate doses with proper monitoring, is very low-risk – is already considered part of the Covid-19 "standard-of-care". So, it's given even to the 'control' arms of trials for other compounds – making both its effects, and those other compounds' effects, harder to disentangle.

All I want now is true randomized trials - and can't at least one of those monitor, or vary the supplementation of, Zinc as well?

A subgroup analysis by self-reported zinc usage was done in the post-exposure prophylaxis RCT . No effect.

https://twitter.com/methodsmanmd/status/1293350242310590464

In vitro means a petri dish. Bleach has antiviral properties in those conditions.

In vitro results are much less meaningful than in vivo results. It can be a useful early validation step, but is far from telling us anything about real world efficacy.

There's enough in vivo studies at this point that in vitro studies should no longer be part of the conversation.