Proof of Concept Creatine Supplementation for Homocystinuria Study

For 7 days, participants will take a 20mg creatine supplement each day.

On the study days participants will ingest 8 hourly meals of controlled amino acid intake, fortified with the necessary macronutrients. Each meal will provide one-twelfth of the participants' daily energy requirements as estimated by 1.5 x Resting Energy Expenditure (REE) and adequate protein at 1.0 g/kg/d, to maintain a metabolic steady state. The meals are in the form of a crystalline amino acid protein shake, and protein-free cookies.