A statement posted on the club's website on Monday night confirmed that he was in intensive care.
No further statement is expected to be released, to protect the privacy of his family.
Holland first began supporting the former Scarborough FC as an eight-year-old in the 1964-5 season, and continued to follow them while working in Norfolk, where he runs an educational publishing company.
He became involved with the Trust when Athletic were formed after Scarborough FC's winding up in 2007.