Robin Roberts Credit: Ida Mae Astute/ABC via Getty;

Robin Roberts doesn't take her millions of well-wishers for granted.

The Good Morning America co-anchor returned to the ABC series on Monday Aug. 20 after an abrupt, three-week break to deal with pre-treatment for a life-saving bone marrow transplant.

A recent tweet reveals that the beloved TV journalist, 51, visited the Vatican in Italy during her break, and she prayed in the holy city -- not just for her health, but for her supportive fans.

"Given special access to the Vatican in Rome today," Roberts wrote in a caption above a photo in which she prays at a simple altar. "Saying prayer for all who have prayed for me. XO"

In June, about five years after her breast cancer battle, Roberts was diagnosed with myelodysplastic syndrome (MDS), a rare blood and bone marrow disorder.

She added that she was "grateful to Italy for renewing my spirit/soul."

"My needle was past 'E' when I left here a couple of weeks ago, but I've got a full tank, so watch out," Roberts told viewers on her Monday return. "I haven't taken this much time off in quite some time."

She is set to undergo the transplant in early September. "I feel alive again and really ready to tackle this next challenge," she said.