system
Given the following post, respond as if you're commenting on Reddit:
human
How are nutrients/chemicals in food dispersed to where they are needed in the body?

For example, how does the calcium in milk you drink find its way to enamel in your teeth, or anticoagulant chemicals in medicine reach the blood stream?
gpt
Almost everything is extracted from food in your intestine and directly transferred to blood. There are lots of blood vessels right next to your intestine that make that work.

(The only exception is fat, which is extracted from food in your intestine and transferred to your lymphatic vessels and *then* transferred to blood.)

From there everything goes to the liver, which removes a bunch of things that are toxic, dumps them into bile, which is then dumped back into your intestine and eventually excreted. After filtering, the liver transfers everything that's worth keeping into your main circulation.

(Fat is again an exception; it bypasses filtering in the liver and goes directly to your main circulation)

Once in main circulation, the nutrients are spread all over, and cells that need them pick them up as they go by. (There are lots of simple and complicated ways for cells to pick up nutrients, so there's a whole another complicated story buried in there, but that's the gist of it.)