Food fortification is designed to build up essential amino acid and micronutrient stores in people over time and without risk, so it is a benign and resourceful way of improving nutrition without making people modify their cooking and eating habits. This chapter focuses on the fortification/supplementation studies of amino acids undertaken to improve nutritional content of animal feeds and food along with their toxicity and regulations. Biofortification differs from regular fortification, rather than incorporating nutrients into the foods when they are being processed it focuses on building plant foods more nutritious as the plants are growing. l-lysine and its monohydrochloride form- l-lysine monohydrochloride, are approved as food additives by the Food and Drug Administration (FDA) and can be used directly to fortify foods for enhanced nutrition and normal consumption. Other amino acids such as l-arginine and l-valine are also approved by FDA and are generally regarded as safe recognized when fortified to a certain prescribed level.