Toft was born on 29 October 1944, the son of Anne Laing and William Vincent Toft. He was educated at Perth Academy.[2][3]
He moved to the South Side in Edinburgh in 1962 when he began his studies in medicine at the University of Edinburgh.[4] He graduated with an MB ChB in 1969 and then, after practical training in Edinburgh hospitals, practised as a general practitioner on Islay and then Orkney. In 1971 he became a Ciba Research Fellow in Endocrinology.
In 1980 he was elected a member of the Harveian Society of Edinburgh and served as Medical Secretary from 1982-1994. He was President of the Society in 1995.[5] In 1987 he was elected a member of the Aesculapian Club and served as Honorary Secretary from 2004-2014.[6]