Methylmalonic Acid
The Methylmalonic Acid (MMA) test is used in the diagnosis of acquired cobalamin (vitamin B12) deficiency in adults and to screen for inherited organic acidemia in neonates and infants. Elevated MMA in either blood or urine indicates vitamin B12 deficiency in adults, with MMA acting as a functional biomarker for vitamin B12 status. In neonates and infants, elevated MMA is associated with inborn errors of metabolism.
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Stephanie Strudley
Stephanie Strudley, CNS, is a functional medicine nutritionist and the founder of Upstream Wellness. She helps driven, health-conscious adults who've done "everything right" and still don't feel like themselves — connecting the dots between symptoms, labs, and lifestyle to uncover what's actually going on. Her approach is shaped by an unconventional path: a background in ecology and systems biology, and her own experience navigating serious, unresolved health challenges before finding root-cause care herself. She doesn't believe in one-size-fits-all protocols or quick fixes — she believes health is more like solving a puzzle than following a formula, and her role is to help clients ask better questions, interpret their own data, and build a plan that fits their unique biology and life.
My websiteFocus areas
Cardiovascular Health
Gastrointestinal Health
Metabolic Health
Women's Health
States of practice
California
Colorado
Maryland
Massachusetts
Oregon
Texas
Washington