Iain Macintyre FRS (30 August 1924 – 18 September 2008) was a British endocrinologist who made important contributions to the understanding of calcium regulation and bone metabolism.

[1] After house posts in Glasgow, Macintyre began as a trainee pathologist in Sheffield, which involved working as a demonstrator in the laboratory of Dr (later Sir) Hans Krebs, the future Nobel laureate.

[citation needed] He joined the chemical pathology department at the Royal Postgraduate Medical School, at the Hammersmith Hospital in London as a registrar.

In 1954 he became the Sir Jack Drummond Memorial Fellow, which enabled him to embark on a career of research in biochemistry, initially under the mentorship of Professor Earl King.

[citation needed] He designed and constructed a flame photometer that enabled very accurate measurements of blood calcium and magnesium levels.

[10] A major contribution to education during Macintyre's time at the Hammersmith Hospital was the organisation of international endocrinology conferences held every two years between 1967 and 1981.