[2] Bell's thesis was on basal metabolism in goitre and contributed to the introduction of iodised salt, as her research showed that increasing the level of iodine in the diet was an effective protection against the illness[1][3] In 1922, Bell was appointed Assistant Lecturer in Physiology, and the following year became a lecturer in Physiology, at Otago Medical School.
From 1930 to 1932 she researched vitamins at University College London and then stayed in England to work as a pathologist, including at Elizabeth Garrett Anderson Hospital.
[1] In 1935, Bell returned to Dunedin[4] and took a position lecturing physiology and experimental pharmacology at Otago Medical School.
[6] In these roles, she both conducted research and found effective ways to communicate the results to the public, such as through magazine and newspaper articles, radio broadcasts and the Plunket Society.
She was a founding member of the Central Milk Council, a watchdog body formed in 1945 to address problems in the industry which had been revealed in an inquiry the previous year.
[6] While on the council she worked to have millk pasteurized, delivered in covered trucks to protect it from sunlight, and to have unhealthy cows destroyed.
In 1950, Bell and her friend Dr Lucy Wills spend eight weeks in Fiji and Samoa to investigate nutritional reasons for tooth decay in the local populations there.
[12] Bell's personal papers, stored at the Hocken Collections of the University of Otago, were inscribed on the UNESCO Memory of the World Aotearoa New Zealand Ngā Mahara o te Ao register in 2019.