A person must take protein supplement or amino acid supplement, and how can we know our body is amino acid deficient?

Eat right: Eat healthy balanced diet no need to take protein supplements , if you eat meat it has all the essential amino- acids Vegans may have a problem if they do not eat enough protein containing foods .

Usually not needed: Protein is made up of amino acids,There are 9 amino acids that need to be eaten every day for best health. They are found in animal products like meat, milk, & eggs, & most healthy people eating 0.8grams of protein for each kg of weight get enough. Plant sources of protein: Soy is OK IF COOKED. Quinoa OK also. For most, though, a combination is needed; eg rice AND beans - but do research first.