She is a demographer with an academic background in biology. She received her PhD and master's degree in sociology with a major in demography and a minor in population health, from the University of Wisconsin-Madison. She received a master’s degree in statistics with a major in population health, and an ScB in biology from the University of Costa Rica. Santamaría-Ulloa is also an associate professor at the Public Health, the Medical Specialties and the Human Nutrition Graduate Programs, and at the Human Nutrition Undergraduate Program at the University of Costa Rica.