"Inherited metabolic disorder" means an inherited enzymatic disorder caused by single gene defects involved in the metabolism of amino, organic, or fatty acids.
"Medically necessary formula and enteral nutrition products" means any liquid or solid formulation of formula and enteral nutrition products for covered individuals requiring treatment for an inherited metabolic disorder and for which the covered individual's physician has issued a written order stating that the formula or enteral nutrition product is medically necessary and has been proven effective as a treatment regimen for the covered individual and that the formula or enteral nutrition product is a critical source of nutrition as certified by the physician by diagnosis. The medically necessary formula or enteral products do not need to be the covered individual's primary source of nutrition.
Va. Code § 38.2-3418.18