system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are banana bags (the IV fluid) yellow?

I would really like to know.
gpt
One of the components of a banana bag is a multi-vitamin injection (MVI). This contains vitamin B2, which is yellow in color due to the chemical structure of riboflavin (B2). Same reason that taking a multi-vitamin as a tablet may cause your urine to be a bright yellow or orange color.