Daily Recommendations. Recommendations for vitamin A are based on age. Infants between 0 and 6 months require 400 mcg per day, whereas infants between 7 and 12 months need 500 mcg per day. Toddlers between 1 and 3 need 300 mcg every day.
The twenty amino acids can be divided into two groups of 10 amino acids. Ten are essential and 10 are nonessential. However, this is really not an accurate dichotomy, as there is overlap between the two groups, as is indicated in the text accompanying the following two charts:
The human body needs a number of amino acids in large enough amounts to maintain good health. Amino acids are found in animal sources such as meats, milk, fish, and eggs. They are also found in plant sources such as soy, beans, legumes, nut butters, and some grains (such as wheat germ and quinoa). You do not need to eat animal products to get all the protein you need in your diet. Essential amino acids cannot be made by the body, and must be supplied by food. They do not need to be eaten at one meal. The balance over the whole day is more important. Nonessential amino acids are made by the body from essential amino acids or in the normal breakdown of proteins.