What is the most common amino acid deficiency found in vegans?

Lysine is considered the most common amino acid deficiency found in vegans due to its relatively low availability in plant-based diets. While many protein sources exist in the vegan diet, lysine is typically less abundant compared to essential amino acids found in animal products. Foods such as legumes, lentils, and soy products are good sources of lysine; however, if these are not adequately consumed, individuals may not get enough of this amino acid.

In contrast, other amino acids in the options provided, such as histidine, methionine, and arginine, can often be obtained through a broader range of plant foods or can be synthesized by the body, which reduces the risk of deficiency compared to lysine. Therefore, when addressing nutritional concerns in vegan diets, lysine is frequently highlighted as critical to monitor to ensure adequate intake and to maintain overall health.