Andrew J. Day, MD
Accepting new patients

Andrew J. Day, MD

  • Endocrinology
Average rating: 5.0
(434 ratings)  
Santa Clarita Primary & Specialty Care | 25775 McBean Parkway, Suite 202, Valencia, CA 91355


Dr. Andrew Day is an endocrinologist who practices at UCLA Health's Santa Clarita clinic.

Dr. Day received his medical degree from the Temple University School of Medicine. He completed his internship and residency in internal medicine at the University of Wisconsin, Madison. He moved to the University of California, Los Angeles to complete a fellowship in endocrinology, diabetes, and metabolism. He received his undergraduate degree from the University of Chicago, where he graduated with honors.

Prior to pursuing a career in medicine, Dr. Day participated in research that studied the associations between sleep and metabolic health. Dr. Day has an interest in medical education and is involved with the David Geffen School of Medicine at UCLA.

Dr. Day was born and raised in Wisconsin. Outside of medicine, his interests include travel, reading, baseball, camping, hiking, kayaking, and enjoying the arts.

Patient Stories

Great UCLA Doctor




Medical Board Certifications

Endocrinology, Diabetes and Metabolism, American Board of Internal Medicine, 2018
Internal Medicine, American Board of Internal Medicine, 2016


Endocrinology Diabetes & Metabolism, UCLA School of Medicine, 2018


Internal Medicine, University of Wisconsin Hospitals and Clinics, 2016


MD, Temple University School of Medicine, 2013


  • Super Doctors® Southern California Rising Stars 2021, 2022, 2023

Medical Services

Areas of Focus

Adrenal disorders
Pituitary disorders
Endocrine disorders
Thyroid disorder



  1. Day A, Yeh M, Livhits M. Surgery for Hyperthyroidism Lowers Cardiovascular Mortality Compared with Radioactive Iodine. Clinical Thyroidology. Jan 2018; 30: 15-17.
  2. Grock S, Day A, Bhat S. Two cases of impaired sensitivity to thyroid hormone with wild-type THRβ gene. Clinical Thyroidology. Aug 2017; 29: 318-321.
  3. Broussard J, Kilkus J, Delebecque F, Abraham V, Day A, Whitmore H, Tasali E. Elevated ghrelin predicts food intake during experimental sleep restriction. Obesity. Jan 2016; 24(1):132-8.
  4. Broussard J, Chapotot F, Abraham V, Day A, Delebecque F, Whitmore H, Tasali E. Sleep restriction increases free fatty acids in healthy men. Diabetologia. Apr 2015; 58(4):791-8.
  5. Pamidi S, Wroblewski K, Broussard J, Day A, Hanlon E, Abraham V, Tasali E. Obstructive sleep apnea in young lean men: impact on insulin sensitivity and secretion. Diabetes Care. Nov 2012; 35(11):2384-9.


  • Super Doctors® Southern California Rising Stars 2021, 2022, 2023