Otdfbt

I read a short story in the mid 1960's and now cannot remember the title. It was in an anthology I think.

The story began with space travelers, male and female. I think they were involved in a planetary colonization program, as they referred to many colonies. The key element was that they included in each colony crew an individual who did not connect well with other people, but he was invaluable for his ability to simply absorb information of every random type and make a valuable connection between disparate facts.

In this story, he was the only one who could solve the mystery of crew members dying unexpectedly and for unknown causes. He connected an obscure factoid about the side effect of a rare metal in certain life forms that was always fatal. He sounds the alarm to evacuate and all were saved.

Found it! I knew I had read it some time ago. Isaac Asimov "Sucker Bait." It was a tough one to find with my limited brain cells, but it pushes all the right buttons.

The crew, in fact, were rather contemptuous of the passengers, and
avoided them.

Eggheads!

Additionally, the individual irritated the captain of the Triple-G space ship.

And as he was about to leave, the captain called out, "Sheffield!"

"Yes?"

"What in Space is a 'noncompos'?"

Sheffield suppressed a smile. "Did he call you that?"

"What is it?"

"Just short for non compos mentis. Everyone in the Service uses it
for everyone not in the Service. You're one. I'm one. It's Latin for
'not of sound mind.' And you know, captain-I think they're quite
right."

In a near-mutiny, the earliest version of a learning-obsessed Sheldon-Cooper-type also managed to get the ship off the planet. During an investigation after the "escape:"

"Because I know what killed the first expedition, and it was only a
question of time before it killed us. In fact, it maybe too late
already. We may be dying now. We may, every one of us, be dead men."

It is not a perfect match, but much of what you are describing sounds like The Voyage of the Space Beagle by A. E. van Vogt. The 1950 book was a fix-up of earlier stories the author had published, mostly in between 1939–1943.

Wikipedia describes the main character thus:

The main protagonist of the novel is Dr. Elliott Grosvenor, the only Nexialist on board (a new discipline depicted as taking an actively generalist approach towards science). It is Grosvenor's training and application of Nexialism rather than the more narrow-minded approaches of the individual scientific and military minds of his other shipmates that consistently prove more effective against the hostile encounters both from outside and within the Space Beagle. He is eventually forced to take control of the ship using a combination of hypnotism, psychology, brainwashing, and persuasion, in order to develop an effective strategy for defeating the alien entity Anabis and saving the ship and our galaxy.

Unfortunately, the specific problem described in the question (with members of the crew being poisoned by a rare metal) does not match the story so closely. However, the story does feature an alien life form that kills members of the crew in a mysterious fashion, so that it (the alien—"coeurl," by name) can extract a certain element from their flesh.