About
John A. Ritzo, MD is a family medicine physician practicing in his hometown of San Mateo, California. He earned his Bachelor of Science in Exercise Science and Sports Medicine from Colorado State University in Fort Collins before pursuing his Doctorate of Medicine at Trinity School of Medicine, with training in both Saint Vincent and the Grenadines and Baltimore, Maryland. He then completed his internship and Family Medicine residency at Central Maine Medical Center in Lewiston, Maine, finishing in 2025. Dr. Ritzo holds a California medical license.
His undergraduate background in exercise science and nutrition shapes how he approaches care. Dr. Ritzo believes that prevention and healthier daily habits deserve as much attention as clinical treatment. He works to minimize the need for medical intervention by helping patients build stronger foundations before illness takes hold. He treats patients across the lifespan, with particular focus on type 2 diabetes, high cholesterol, and hypertension. Returning to San Mateo carries personal meaning for him. His father practiced medicine in this same community, and Dr. Ritzo sees his work here as both a professional commitment and a personal one. Outside the office, he enjoys baseball, fitness, and finance and investing.
Education & Training
Undergraduate
Colorado State University, B.S. Exercise Science & Sports Medicine, 2014
Medical School
Trinity School of Medicine, Ribishi, Saint Vincent and the Grenadines / Baltimore, MD
Residency
Family Medicine, Central Maine Medical Center, Lewiston, ME (2023-2025)
Additional Training
Internship, Central Maine Medical Center, Lewiston, ME (2022-2023)
Conditions Treated
Who is Dr. Ritzo right for?
Dr. Ritzo is a strong fit for adults who want a physician focused on prevention and long-term wellness. Patients managing type 2 diabetes, high cholesterol, or hypertension benefit from his proactive, habit-based approach. He works well with patients who value direct access to their doctor and dislike rotating through different providers. Those interested in exercise, nutrition, and lifestyle-driven health will find his background in exercise science a practical asset.
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Frequently Asked Questions
Dr. Ritzo treats a broad range of conditions across the lifespan as a family medicine physician. He has particular clinical focus on type 2 diabetes, high cholesterol, and hypertension. Beyond managing existing conditions, he emphasizes prevention and lifestyle habits to reduce the need for medical intervention over time.
Dr. Ritzo draws on his undergraduate training in exercise science and nutrition to guide his preventive approach. He believes that healthier daily habits are too often overlooked in medical care. He works alongside patients to build a foundation of wellness through lifestyle changes, not just clinical treatments.
Dr. Ritzo earned his Doctorate of Medicine from Trinity School of Medicine, with campuses in Saint Vincent and the Grenadines and Baltimore, Maryland. He completed both his internship and his Family Medicine residency at Central Maine Medical Center in Lewiston, Maine, finishing his residency in 2025. Before medical school, he studied Exercise Science and Sports Medicine at Colorado State University.
Dr. Ritzo completed his Family Medicine residency at Central Maine Medical Center in 2025 and holds a California medical license. For specific board certification status, prospective patients should contact the practice directly.
Yes. Dr. Ritzo operates a dedicated doctor model through MDVIP. When you visit the office, you see Dr. Ritzo specifically, not a nurse practitioner or physician assistant. That consistency supports the kind of relationship-driven care he prioritizes.
Dr. Ritzo holds a Bachelor of Science in Exercise Science and Sports Medicine from Colorado State University. He actively incorporates that training into his medical practice. He uses knowledge of exercise and nutrition to help patients optimize their health alongside traditional medical care.
San Mateo is Dr. Ritzo's hometown. He returned after his training in the Caribbean, Maryland, and Maine to care for the community that raised him. His father also practiced medicine in San Mateo, and Dr. Ritzo carries that legacy forward in his own practice.
Dr. Ritzo practices family medicine, which means he addresses diseases and health concerns across the lifespan. He sees adult patients and applies his training to both preventive care and chronic disease management at every stage of life.
Doctor profile last updated April 10, 2026