"Recommended amount" refers to the suggested or advised quantity or level of something that is considered appropriate or beneficial for a specific purpose. Full definition
Did you know that a single tomato can provide 40 % of the daily recommended amount of Vitamin C? (thebettyrocker.com)
Just one pear packs 15 % of your daily recommended amount of fiber. (health.com)
The daily recommended amounts for vitamins are in this list, and the same for the minerals you can find on page 3 of this document (PDF). (evilcyber.com)