230 Savage Hall
Ithaca, New York
Division of Nutritional Sciences


Kimberly O’Brien received her B.S. in Biology from the University of New Hampshire and her PhD in Nutrition from the University of Connecticut, Storrs. Her professional training included fellowships with the National Institute of Child Health and Human Development, Laboratory of Theoretical and Physical Biology/Section for Metabolic Analysis and Mass Spectrometry and the Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine. Professor O'Brien joined the faculty in the Division of Nutritional Sciences after working for 10 years as a faculty member in the Center of Human Nutrition at Johns Hopkins Bloomberg School of Public Health.

Professor O’Brien’s research has centered on studies designed to better understand mineral metabolism and bone health in infants, children, and pregnant and lactating women in both developed and developing countries. To address issues of calcium metabolism, she has undertaken metabolic studies in groups including children from osteoporotic families, pregnant and lactating adolescents, and children with chronic diseases such as cystic fibrosis and HIV infection. Her current research focuses on the impact of adolescent pregnancy, particularly among minority populations, on maternal and fetal bone health, risk of anemia, and maternal and neonatal vitamin D and iron physiology.  Partitioning of nutrients between the mother and fetus is addressed at the cellular level by assessing placental mineral transporters in relation to maternal and neonatal status.

To allow for kinetic studies of human mineral metabolism, a mass spectrometry laboratory has been added to the existing resources in the Human Metabolic Research Unit. This laboratory includes instrumentation for high-sensitivity mineral stable isotope analysis using a  Triton TI magnetic sector thermal ionization mass spectrometer. This laboratory also provides analytical services through collaboration with other academic institutions in the country.

Calcium Metabolism and Bone Health; Maternal and Neonatal Anemia, Control of Maternal/Fetal Nutrient; Partitioning and Placental Mineral Transport;  Mineral Metabolism in Pregnant Adolescents and in Women Carrying Multiples, Vitamin D Kinetics during Pregnancy

      O'Brien KO, Ru Y. Iron Status of North American Pregnant Women: Other Evidence from the United States and Canada. Am J Clin Nutr 2017; Oct 25 doi:10.3945/ajcn.117.155747

de Angelis P, Miller RK, Darrah TH, Katzman PJ, Kent T, O’Brien KO. Elemental content of the placenta: A comparison between two high-risk obstetrical populations, adult women carrying multiples and adolescents carrying singletons. Environmental Research 2017; Jul 14;158:553-565. doi: 10.1016/j.envres.2017.07.008

Akoh CC, Pressman EK, Whisner C, Thomas C, Cao C, Kent T, Cooper E, O’Brien KO. Vitamin D Mediates the Relationship between Placental Cathelicidin and group B streptococcus Colonization during Pregnancy. J Reprod Immunol. 2017 Jun;121:42-48. doi: 10.1016/j.jri.2017.06.001.

Akoh CC, Pressman E, Cooper E, Queenan R, uPillittere J, O’Brien KO. Vitamin D is Associated with Infections and Proinflammatory Cytokines During Pregnancy. Reprod Sci. 2017 Jan 1:1933719117715124. doi: 10.1177/1933719117715124

Akoh C, Pressman EK, Cooper E, Queenan RA, Pillittere J, O’Brien KO. Prevalence and Risk Factors for Infections in a Pregnant Adolescent Population. J Pediatr Adoles Gynecology; 2017 Feb;30(1):71-5. 

Weber D, O’Brien KO, Schwartz GJ. Evidence of disordered calcium metabolism in adolescent girls with type 1 diabetes: an observational study using a dual-stable calcium isotope technique. Bone 2017; 105:184-90. 10.1016/j.bone.2017.09.001

Whisner CM, O’Brien KO, Cooper EM, Pressman EK. Pregnant Adolescents Participating in a Vitamin D Supplementation Trial Have a Preference for Receiving Prenatal Nutrition and Health Information via Digital Media Platforms. Med J of Obstet and Gynecol 2016; 44(4):1089.

Ru Y, Pressman EK, Cooper EM, Guillet R, Katzman PJ, Kent T, Bacak SJ, O’Brien KO. Iron Deficiency and Anemia are Prevalent in Women Carrying Multiples. Am J Clin Nutr 2016; 104(4):1052-60.

Best CM, Pressman EK, Cao C, Cooper E, Guillet R, Yost OL, Galati J, Kent T, O’Brien KO. Maternal Iron Status During Pregnancy compared with Neonatal Iron Status Better Predicts Placental Iron Transporter Expression in Humans. FASEB J. 2016; 30(10):3541-3550.

Layden AJ, O’Brien KO, Pressman EK, Cooper EM, Kent TR, Finkelstein JL. Vitamin B12 and Placental Expression of Transcobalamin in Pregnant Adolescents. Placenta 2016; 45:1-7.

Ware N, Oni L, O’Brien KO, Abrams SA, Rees L. The Dual-Tracer Stable Isotope Method to Measure Calcium Absorption in Children on Dialysis; A New Use of An Old Technique. Pediatric Nephrology 2016; 2016 Oct;31(10):1713-4. doi: 10.1007/s00467-016-3435-0. Epub 2016 Jun 25.

Kothapalli KSD, Gadgil MS, Carlson SE, O’Brien KO, Zhang JY, Park HG, Ojukwu K, Zou J, Hyon SS, Joshi KS, Brenna JT. Positive Selection on a Regulatory Insertion-Deletion Polymorphism in FADS2 Influences Apparent Endogenous Synthesis of Arachidonic Acid. Mol Biol Evol 2016; Jul;33(7):1726-39.

Whisner CM, Bruening M, O’Brien KO. A Brief Survey of Dietary Beliefs and Behaviors of Pregnant Adolescents.  J Pediatr Adolesc Gynecol. 2016 Oct;29(5):476-81.  

Omotayo MO, Dickin KL, O’Brien KO, Neufeld LM, De-Regil LM, Stoltzfus RJ. Calcium Supplementation to Prevent Preeclampsia:  Translating Guidelines into Practice. Advances in Nutrition 2016; Mar 15; 7(2):275-8. doi:10.3945/an.115.010736

Cao C, Pressman EK, Cooper EM, Guillet R, O’Brien KO. Pre-pregnancy Body Mass Index and Gestational Weight Gain Have a Limited Impact on Maternal Hepcidin but no Significant Impact on Maternal or Neonatal Iron Status. Repro Sci 2016; May;23(5):613-22.   

Lee S, Guillet R, Cooper E, Westerman M, Orlando M, Kent T, Pressman E, O’Brien KO. Prevalence of Anemia and Associations Between Neonatal Iron Status, Hepcidin and Maternal Iron Status Among Neonates Born to Pregnant Adolescents. Pediatr Res 2016; Jan;79(1-1):42-8. doi: 10.1038/pr.2015.183. Epub 2015 Sep 18.

Thomas CE, Guillet R, Queenan RA, Cooper EM, Kent TR, Pressman EK, Vermeylen FM, Roberson MS, O’Brien KO. Vitamin D Status is Inversely Associated with Anemia and Serum Erythropoietin During Pregnancy. Am J Clin Nutr. 2015; 102(5):1088-95.

DelaValle D, Glahn R, Shaff J, O’Brien KO. Iron Absorption from Intrinsically-Labeled Lentils. J Nutr 2015; 145(10):2253-7.   

Ye K, Cao C, O’Brien KO, Gu Z. Natural Selection on HFE in Asian Populations Contributes to Enhanced Non-heme Iron Absorption. BMC Genet. 2015 Jun 10;16:61. doi: 10.1186/s12863-015-0223-y.

Adjunct Professor, University of Rochester School of Medicine and Dentistry, Department of Obstetrics and Gynecology, Rochester, NY

I am a member of the USDA/DHHS Technical Expert Committee Working Group 1 for the Birth to 24 Months Project: As part of this group of scientists our goal is to evaluate the evidence base to support the inclusion of infants and children from birth to 24 months of age in the Dietary Guidelines for Americans. Findings from this working group will be published in topic specific manuscripts in The American Journal of Clinical Nutrition.

I was invited as the guest lecturer for the 2017 Summer Lectureship Series at Iowa State University. In this role I presented a 3-day course that was focused on recent advances in the field of vitamin D metabolism. This was offered to the graduate students (and interested faculty) in the Animal Science and Nutrition Departments.

I am a permanent member of the NIH Integrative Nutrition and Metabolic Processes (INMP) Study Section.
In collaboration with physicians at the UofR and with current doctoral students, we have co-authored on-line continuing education articles for obstetrical and medical and health professionals for the Peri-FACTS® Academy. This is an online continuing education program that allows OB/GYN health care providers earn nursing contact hours and CME credits any time, from any computer;


I teach a one-semester undergraduate Human Anatomy and Physiology course and co-teach a graduate course on micronutrient metabolism. I am committed to promoting hands-on, investigative, opportunities for undergraduate and graduate students interested in clinical research. Our laboratory group actively involves undergraduates; many of whom are authors on the research generated. Scientific writing is emphasized and facilitated with weekly undergraduate and graduate writing groups and with weekly meetings for all on-site and off-site study personnel.  Graduate and post-doctoral students gain mentoring experience by providing guidance in methods development and data analysis to undergraduate laboratory students.

NS3410 - Human Anatomy and Physiology
NS6310 - Micronutrients (Primary Instructor Charles McCormick)

NS6190 - Field of Nutrition Seminar

NS4010 - Independent Study

BIOG 4990 - Independent Study

NRSA Fellowship 1993-1995 - Baylor College of Medicine, Children's Nutrition Research Center, Houston, TX

IRTA Fellowship - 1991-1993 - National Institutes of Health, Section on Metabolic Analysis and Mass Spectrometry, Bethesda, MD

PhD - 1991     University of Connecticut, Nutrition

BS   - 1985     University of New Hampshire, Biology