Lysine – why must it be supplied through food? Its role in the body, requirements, and sources of lysine

Lysine is an essential proteinogenic amino acid that is not synthesized by the human body and therefore must be supplied externally – through a daily diet or, if needed, in the form of supplements. Lysine plays many important roles in the human body. It is a component of hormones and antibodies, may strengthen the immune and cardiovascular systems, and is also involved in tissue regeneration and improving skin elasticity and condition.