After two years as a senior registrar at Guy's Hospital,[3] in 1959, Smithells became a lecturer at the University of Liverpool and became consultant paediatrician and medical superintendent for Alder Hey Children's Hospital in 1964. In 1968 he took up the chair of Paediatrics and Child Health at Leeds University, and worked in all the hospitals in Leeds.[1] By 1962, Smithells had established congenital abnormality register and genetic counselling service at the University of Liverpool.[6]
Dick Smithells work during his long career was the prevention of disease in children.[1] Early in his career, Smithells recognized the effects of poor nutrition in pregnant women and how it led to birth defects with studies taking many years. Indeed his most notable research in his career, was the establishing link between folic acid deficiency and neural tube defects. It wasn't until 1991 that the Medical Research Council ratified his decision by recommending that pregnant women's diets should contain sufficient folic acid.[3]
Many of Smithells early papers were about the effects of Thalidomide on the foetus,[6] and he developed a special unit to support children damaged by thalidomide,[4] and was later heavily involved in securing compensation for children disabled by the
thalidomide drug, and taking a position in the Thalidomide Trust to facilitate that role.[3]