Jeffrey Roizen, MD, PhD, FAAP

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Jeffrey Roizen, MD, PhD, FAAP, is an attending physician at Children's Hospital of Philadelphia who specializes in treating patients with diabetes, hyperinsulinism, endocrine and other disorders.

Areas of Expertise: Metabolic bone disease, Hypercalcemia, Hypocalcemia, Hyperparathyroidism, Pseudohypoparathyroidism, Obesity, Type 1 Diabetes, Type 2 Diabetes, Pituitary disease
Locations: Main Hospital

Appointments and Referrals: 1-800-TRY-CHOP (1-800-879-2467)


Dr. Roizen is a clinician scientist at the Children’s Hospital of Philadelphia. He is a tenure track Assistant Professor at the University of Pennsylvania with dual appointments in Pediatrics and Cell and Molecular Biology.

His clinical interests include metabolic bone diseases with a focus on vitamin D metabolism, hyperparathyroidism and pseudohypoparathyroidism as well as obesity, type 2 diabetes and type 1 diabetes.

His research program uses his expertise as a pediatric clinician scientist, consultation and collaboration with Penn and CHOP niche experts and subsidized use of singular resources available at CHOP/Penn to dissect the biology of vitamin D metabolism and vitamin D action and leverage this knowledge towards rationally designed, targeted therapies that ultimately aim to improve the health and well-being of patients.

Dr. Roizen works in collaboration with Dr. Falk, Dr. Khurana, Dr. Levine and Dr. Hakonarson. Each of whom has an active laboratory research program that complements and extends Dr. Roizen’s clinical and research studies.

Dr. Roizen has more than 40 papers, patents and chapters. He is a member of numerous professional societies, including the American Society for Bone and Mineral Research, the Endocrine Society, the Pediatric Endocrine Society, the Juvenile Diabetes Research Foundation and the American Diabetes Association. He is a Fellow of the American Academy of Pediatrics.

Education and Training

Medical School

MD - Washington University School of Medicine, Saint Louis, MO


Pediatrics - Children's Hospital of Philadelphia, Philadelphia, PA


Pediatrics - Children's Hospital of Philadelphia, Philadelphia, PA


Pediatric Endocrinology - Children's Hospital of Philadelphia, Philadelphia, PA

Board Certification

Pediatric Endocrinology – American Board of Pediatrics
Pediatrics – American Board of Pediatrics

Graduate Degree

PhD - Washington University School of Medicine, Saint Louis, MO

Titles and Academic Titles

Attending Physician

Assistant Professor, Perelman School of Medicine at the University of Pennsylvania

Conditions Treated

Departments and Services

Research Interests

Vitamin D metabolism and action|
Prader-Willi Syndrome
Type 1 diabetes
Type 2 diabetes



Selected Papers


Roizen JD, Li D, O'Lear L, Javaid MK, Shaw NJ, Ebeling PR, Nguyen HH, Rodda CP, Thummel KE, Thacher TD, Hakonarson H, Levine MA.: CYP3A4 mutation causes vitamin D-dependent rickets type 3. Journal of Clinical Investigation Feb 2018 Notes: doi: 10.1172/JCI98680.


Xi D, Long C, Lai M, Casella A, O’Lear L, Kublaoui B, Roizen JD: Ablation of oxytocin neurons causes a deficit in cold stress response. J. Endocr. Soc. 1(7), July 2017 Notes: doi: 10.1210/js.2017-00136.


Roizen, JD*, Hysinger EB*, Mentch, F, Connolly, J, Bradfield, JP, Almoguera, B, Allen, J, Levine, MA, Hakonarson, H. : The Causal Relationship of Vitamin D and Asthma: A Cross-sectional and Mendelian Randomization Analysis. Journal of Allergy and Clinical Immunology 138(6): 1747-1749, Dec 2016 Notes: *co-first authors.

Roizen JD, Danzig J, Groleau V, McCormack S, Casella A, Harrington J, Sochett E, Tershakovec A, Zemel BS, Stallings VA, Levine MA. Resting Energy Expenditure Is Decreased in Pseudohypoparathyroidism Type 1A. J Clin Endocrinol Metab. 2016 Mar;101(3):880-8. doi: 10.1210/jc.2015-3895. Epub 2015 Dec 28. PMID: 26709970.


Roizen, JD, Danzig, J, Groleau, V, Casella, A, Harrington, J, Sochett, E, Tershekovec, A, Zemel, B, Stallings, V, and Levine, MA. Resting Energy Expenditure is Decreased in Pseudohypoparathyroidism Type 1A. J Clin Endocrinol Metab. 2015 Dec 28:jc20153895. [Epub ahead of print] PubMed PMID: 26709970.

Thacher TD, Fischer PR, Singh RJ, Roizen J, Levine MA. CYP2R1 Mutations Impair Generation of 25-hydroxyvitamin D and Cause an Atypical Form of Vitamin D Deficiency. J Clin Endocrinol Metab. 2015 May 5:jc20151746. [Epub ahead of print] PubMed PMID: 25942481.


Roizen, J. and Levine, MA. A meta-analysis comparing the Biochemistry of Primary Hyperparathyroidism in Youths to the Biochemistry of Primary Hyperparathyroidism in Adults. J Clin Endocrinol Metab: 2014; Dec;99(12):4555-64. jc20142268.

Roizen, MF and Roizen JD. Vitamin D and your patients: don't accept wimpy. Anesth Analg 2014;119(3): 503-505.


Roizen JD, Shah V, Levine MA, Carlow DC. Determination of reference intervals for serum total  calcium in the vitamin D-replete pediatric population. J Clin Endocrinol Metab. 2013 Dec;98(12):E1946–50.

Roizen J*, Xi D*, Lai M, Gandhi N, Kublaoui B. Paraventricular nucleus Sim1 neuron ablation mediated obesity is resistant to high fat diet. PLoS ONE. Public Library of Science; 2013;8(11):e81087. (*Co-first authors)



Roizen JD, Levine MA, and Carlow, D. 2012 Application of Vitamin D Status to Development of normal Ranges for Serum Calcium Concentration in the Pediatric Population. ASBMR 2012.

Roizen JD, Sasson I, Levine MA. Modulation of CYP2R1 expression: A Potential Mechanism for Determining Vitamin D Requirements in Aging and Obesity. ENDO Society 2012.

Roizen JD, Zhou J, and Levine MA. Polymorphisms in the CYP2R1 Gene Present in the General Population Affect 25-hydroxylase Activity. ASBMR 2012.


Roizen JD, Levine MA: Nature and Nurture: Multifactorial rickets in two pre-school aged children. PAS Annual Conference 2011.

Awards and Honors

2018, International Vitamin D Workshop Young Investigator Award
2017, University of Pennsylvania Pathways Scholar
2017, Juvenile Diabetes Research Foundation Innovative Approach Award
2016, Endocrine Society Early Investigator Award
2015, VITALS Patient Choice, Compassionate Physician and On Time Doctor Awards
2015, Pediatric Endocrine Society Clinical Scholar Award
2013, Endocrine Society AMGEN Endocrine Scholars Award
2013, Pediatric Endocrine Society Research Fellowship

Editorial and Academic Positions

Editorial Positions

Reviewer, Journal of Clinical Endocrinology and Metabolism

Leadership and Memberships

Memberships in Professional Organizations

Pediatric Endocrine Society (Obesity Committee)
Philadelphia Endocrine Society, President