Semi-essential amino acids are those that the body can usually produce on its own, but may need to be obtained from the diet under certain conditions, such as illness or stress. Examples of semi-essential amino acids include arginine and cysteine. These amino acids play crucial roles in various bodily functions, including protein synthesis and immune response. While the body can synthesize semi-essential amino acids, dietary sources can enhance their availability and support overall health. Foods rich in protein, such as meat, fish, dairy, and legumes, are good sources of these amino acids. Ensuring a balanced diet can help maintain optimal levels of semi-essential amino acids.