Dr.CardioMD said:

The version of this that has an answer is narrower than the version being asked.

Filing a mild objection. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit. Pushing back on the anecdote-stacking. Twenty people reporting the same thing is twenty samples from the same self-selected pool, not twenty independent confirmations.

Correct me if the detail matters more than I have assumed.

Adding the numbers, since they settle part of this. Worth stating the units and the reference range whenever you post a number here. A large fraction of the apparent disagreement in these threads is two people using different units and both being right.

TirzTom said:

Twenty people reporting the same thing is twenty samples from the same self-selected pool, not twenty independent confirmations.

Adding the part of the answer the thread has not reached. The mechanism and the magnitude are separate questions. Agreeing that something happens says nothing about whether it happens enough to act on.

A narrower follow-up, since the general answer is now clear:

How would you tell the difference between that and the alternative explanation?

Closing the loop on my own question.

Update — I was wrong in the opening post, specifically about the direction. Correcting it here rather than editing it away.