Methods for increasing the bioabsorption of amino acids and for preventing the development of nitrate tolerances in a human or animal are disclosed. The methods include administering to the human or animal a pharmaceutically effective amount of an amino acid compound consisting essentially of a nitrate or nitrite of an amino acid selected from the group consisting of Aspartic Acid, Cysteine, Glycine, Lysine, Methionine, Proline, Tyrosine, Phenylalanine, Carnitine, Taurine, and Betaine.
