Valine
Valine promotes mental vigor, muscle coordination and calm emotions. Since it is a branched-chain amino acid, it can be used as an energy source in the muscles, and in doing so preserves the use of glucose.
Very high levels of valine can cause symptoms such as a crawling sensation on the skin, as well as hallucinations. Individuals with kidney or liver disease should be careful in consuming high intakes of amino acids without consulting their doctor.
Valine is often used by bodybuilders, (in conjunction with leucine and isoleucine), to promote muscle growth, tissue repair and energizer, although little scientific evidence supports these claims.
Studies, however, have shown that these three substances might be useful in restoring muscle mass in people with liver disease, injuries, or who have undergone surgery.
Good sources for this nutrient include dairy, meat, grain, mushrooms, soy and peanuts.