honestly that video was surprising on how safe zinc is. I mean he went so beyond anything close to a reasonable dose. bro was eating tubes of dental paste.
Growing up and recently, I've been anemic (iron deficient) without any obvious medical cause. That requires supplementation with an unusual amount of iron.
Also, I'm vitamin A deficient at baseline and have to take large amounts, around 15k IU/day, to stay within the "normal" range. (50% above ordinary UL.)