You're just exemplifying the point. Who says you have to announce something a specific way first time?

Back in the days it would be "you can't just publish trial papers, it has to go through the church"

Yes, back in the day, the church would censor evidence that it disagreed with.

Today, we demand evidence to back up claims whether or not we want to believe them.

> Who says you have to announce something a specific way first time?

Technically, at our current World state, government regulations say that. And yeah, you have to have the correct credentials and submit your paper to the correct institutions.

Superficially, the system is architectured exactly like the one you are complaining, while in a deeper level every component works in a completely different way. What in practice means that it right now works quite well (could improve, but it works), but it's just a series of isolated institution failings (instead of a full system failure) away from becoming like the other. So, well, keep those institutions in check, but unless somebody comes up with a better system design, there's little point on complaining about it.

Which government regulations are those? Could you please provide a CFR citation?

The World Fact Check Act of 2023.

>clinical trial papers

There are multiple occasions in history where a landmark paper was laughed at just to be proven right later. It hardly matter the medium you use to publish.

How did Galileo and Darwin announce their discoveries?

the medium you use does not establish the truth of your claim.

"Peer reviewed scientific journal" is, at least in theory, a process as much as a medium, and the process at least makes an attempt to screen the worst misinformation or least rigorous scientific methodology through the mechanism of peer review.

(That it often fails at this isn't a point in dispute. The fact that the medium entails a process and that the process, at least nominally, serves truth is.)

There's also the reputational role that such journals serve, effectively transferring the trust bestowed on the journal to the authors appearing within it, where trust is a belief extended beyond the extent of verifiable fact though not in opposition to them (as in the case of blind faith).

To that extent, and in a world in which each individual receiving a piece of information cannot independently assess and verify that information, your premise is in large part false: the medium used does serve to indicate the truth of a claim.

(As someone who's made a point of publishing pseudonymousely and in numerous online, unreviewed media, I'm aware of the challenges of trying to assert facts, even those which are reasonably independently verifiable, without the benefits of a persistent and highly-established identity or other indicia of trust, reputation, or credentialing. In balance I prefer the freedoms that come with this, though the challenges are also considerable.)

The problem with that is, if it's not amplified on social media, it doesn't exist.

There were trials where it was shown that sufficient Vitamin D levels (most people are deficient) is very effective in preventing COVID. It got minor attention, but no-one is pursuing it on a widespread basis. Maybe it works maybe not, but even if there were clinical trials, it gets crowded out by what's being widely circulated in the media.

It must be your bubble/country, because in France it has been said and recommended by the Health Ministry that it probably helps, and doctors prescribe supplements with Vitamin D en masse.

Vitamin D has been recommended forever for general health and is available over the counter. Nothing is stopping people from taking and giving vitamin D in huge doses.