Deborah O'Connor

Deborah O'Connor PhD, RD
Senior Associate Scientist, Translational Medicine, Hospital for Sick Children, Scientific Associate Staff, Department of Pediatrics, Division of Neonatology, Mount Sinai Hospital, Sinai Health System
Department of Nutritional Sciences
Contact Info
T: (416) 978-7235
F: (416) 978-5882
Medical Sciences Building, 5th Floor, Room 5253
1 King's College Circle
Toronto, ON, M5S 1A8
Appointment Status Primary
Accepting new students
PhD, University of Illinois
MS, University of Illinois
Registered Dietitian
BASc, University of Guelph


Research Synopsis

Our research program is focused on two broad areas of maternal and infant nutrition. First, we are interested in understanding the factors that affect the folate and one-carbon (e.g. vitamin B12) nutrient status of women, infants, and young children. In particular, we are investigating the role folic acid fortification, vitamin and mineral supplementation and colonic bacterial folate biosynthesis play on the folate status of women of reproductive age. Folate and other one carbon nutrients are critically involved in prevention of birth defects and emerging evidence suggests these nutrients also play important roles in epigenetic programming of adult disease.

Second, our research group is actively engaged in supporting human milk feeding of vulnerable infants—specifically the hospitalized infants who have unique nutritional requirements. We have been studying the clinical indications for pasteurized donor human milk when mother’s milk is unavailable and  the impact of feeding nutrient-enriched mother’s own and donor milk  during initial hospitalization and early after hospital discharge on the growth, body composition and development (cognitive and motor) of very low birthweight infants during the first 5 years. With our expert collaborators, we are investigatcoling the role that type of early feeding plays on the gut microbiome of the infants and how this may mediate short- and long-term health outcomes.

Publications and Awards

View PubMed search of this faculty member's recent publications.

Honours and Awards

2020 Earle Willard McHenry Award for Distinguished Service in Nutrition, Canadian Nutrition Society

2020 Earle W. McHenry Chair, University of Toronto

2016 Faith Elizabeth Winifred (Rusted) Bayley Nutrition Lectureship (Memorial University)

2015 Khursheed Jeejeebhoy Award, Canadian Nutrition Society

2014 Chair, Vitamin Research in Human Milk and Development, University of Toronto

2011 President’s Award Nomination, The Hospital for Sick Children

2011 Teaching Award: Graduate Student Mentorship (Runner-up), University of Toronto

2000 Pinnacle Award of Excellence, Ross Products Division, Abbott Laboratories