Which of the following is not an essential nutrient for human?

Explanation

This question is asking which of the listed nutrients is NOT essential for humans. The options include vitamin A, lysine, glucose, calcium, and iron. Essential nutrients are those that the human body cannot produce on its own, and therefore must be obtained through the diet. Vitamin A, glucose, calcium, and iron are all essential nutrients for humans as they play important roles in bodily functions. Vitamin A is important for vision and immune function, glucose is a source of energy for the body, calcium is important for bone health and muscle function, and iron is essential for blood oxygen transport. That leaves option B, lysine, as the answer. Lysine is an amino acid, which are the building blocks of proteins. While lysine is important for protein synthesis, it is not considered an essential amino acid because the human body can synthesize it on its own. In summary, the nutrient that is NOT essential for humans is lysine. It is important to have a balanced diet that includes all essential nutrients to maintain good health.