If the captain has died of scurvy, the crew were already dead. Who is going to write in the Captain's log, if the captain is dead?

You've presented zero evidence of your hypothesis. There's over five thousand years of history about scurvy. It's causes and prevention are well understood.

Without any scientific evidence and data, you're litterly just making shit up. You're not a qualified biologists and you've done zero research. Eating meat alone will cause a vitamin c deficiency and scurvy. That's a scientific fact. And will remain so you until someone, anyone presents data that refutes that.

If you can point me to any scientific research or evidence, real historical evidence, I'd love to read it. Because if you go and actually read some shit yourself, well, start with Cook's journals. His research into scurvy was ground breaking and led to the great age of discovery.