The CBS Mornings co-host, 69, used a custom T-shirt to give an update on the chat show queen's condition after her 70-year-old friend was treated for a violent stomach bug that was so severe she was hooked to an intravenous drip.
King posed in her shirt for snaps posted to Instagram, with the front of the top emblazoned with the message: "OPRAH is FINE! Thank you for asking."
CBS Mornings co-host Gayle King has updated viewers on friend Oprah Winfrey's condition. (AP PHOTO)
Another image of King showed her displaying the back of the T-shirt, which carried the message to fans: "She appreciates your concern!"
King said in a caption alongside the shots she had decided to wear the top as "10 people" in the office had asked her the "same question" about Winfrey's condition.
King said earlier this week Winfrey was unable to appear on her CBS show because she was suffering from a virus.
"She had some kind of stomach thing - stomach flu - stuff was coming out of both ends," King said on Tuesday.
"I won't get too graphic.
"Needless to say, she ended up in the hospital - dehydration, had to get an IV - it was a very serious thing."
The news anchor said Winfrey was trying to "rally" but could not manage to make it to the show.
A spokesperson for Winfrey said the presenter-turned-media mogul was "recovering following a stomach flu" and had "received an IV due to dehydration at the recommendation of her doctor".
"She is resting and feeling better every day," the spokesperson said.
Despite King's initial message about Winfrey being in hospital, the presenter then took to Instagram to clarify she had not been treated in a ward.
"She was sidelined with a stomach virus that caused such dehydration that she went to the hospital to get an IV drip," she added in a caption alongside a video of her talking to Winfrey on FaceTime.
"I thought I made that clear but next thing I know I'm surprised to see headlines that scream 'Oprah's hospitalised!' (She was NOT!)
"And I'm bombarded with calls asking if Oprah is OK.
"The answer is yes! And now let's go straight to the source."