That's 0 milligrams. 0 magnesium would be "0 Mg" (pay attention to capitalisation). Or even "0mg Mg".
Mg: 0 mgIUPAC convention needs a space between number and unit. You can only omit the space for % or degrees.
people are focused on other wrong things but.... the past participle of run is runhttps://homework.study.com/explanation/what-is-the-past-participle-of-run.html
A long time ago I bought a generic brand chip just because it had 0mg Cholesterol! in bold print on the front. They were awful to eat but the picture was worth a few hundred likes on Twitter (Currently known as Elon Musk's X) back then.
Instead of arguing about 0Mg vs 0mg - use the best of both and upset everyone: 0ᴍg
youve heard of uppercase and lowercase, meet middlecase