Impact on Isoleucine and Valine Supplementation When Decreasing Use of Medical Food in the Nutritional Management of Methylmalonic Acidemia

Methylmalonic acidemia (MMA) is an autosomal recessive disorder treated with precursor-free medical food while limiting natural protein. This retrospective chart review was to determine if there was a relationship between medical food, valine (VAL) and/or isoleucine (ILE) supplementation, total protein intake, and plasma amino acid profiles. Methods A chart review, of patients aged 31 days or older with MMA treated with dietary intervention and supplementation of VAL and/or ILE and followed at the Children's Hospital Colorado Inherited Metabolic Diseases Clinic. Dietary prescriptions and plasma amino acid concentrations were obtained at multiple time points. Baseline mean total protein intake for five patients was 198% of Recommended Dietary Allowance (RDA) with 107% natural protein and 91% medical food. Following intervention, total protein intake ( = 0.0357), protein from medical food ( = 0.0142), and leucine (LEU) from medical food ( = 0.0276) were lower, with no significant change in natural protein intake ( = 0.2036). At baseline, 80% of patients received VAL supplementation and 100% received ILE supplementation. After intervention, only one of the cohort remained on supplementation. There was no statistically significant difference in plasma propiogenic amino acid concentrations. Decreased intake of LEU from medical food allowed for discontinuation of amino acid supplementation, while meeting the RDA for protein.