There’s actually a really good reason for that. The body doesn’t have a good way to get rid of excess iron except by bleeding, so it’s fairly easy for someone without a period to get iron poisoning from vitamins with iron in them. Women’s vitamins assume the person taking them loses a significant quantity of blood every month. Not only should men not take them, women whose birth control eliminates their period completely shouldn’t take them either.
My money is on it being a way to get around political donation limits - if you’re buying a product, you aren’t donating. Elon can buy a handful of these to give out to his buddies, and it doesn’t count as donating a million dollars to Trump’s campaign.