I realise this may just be me, and if it is then I am definitely unreasonable!
I gave blood every three months for years and during those years I slowly became more and more anaemic. I was in my twenties, healthy and eating well, and my periods were not heavy.
We know that heavy periods (over 80ml per month) can cause anaemia. This equates to 240ml every three months. But for some reason the NHS doesn't mention that giving away 470ml in a donation might cause anaemia too.
I've since had babies and ended up with an iron infusion. These are expensive. But now I have a lovely iron store, likely to last me years and years. I see the NHS is desperate for donors (link below) - should I restart donating and give it all away again? If I get anaemic again they will say 'take iron pills', but I've tried a variety of these before and they do not agree with me. So I can choose to give blood and eventually need iron pills and be permanently constipated, or I can choose not to, and be happy and healthy. I would donate if they would give me an iron infusion at a reasonable 'ideal' level of ferritin, rather than only doing it once ferritin is 5 or whatever and I can barely function.
I'm O negative. The NHS really really wants my blood, according to the article below. But not enough to offer me another iron infusion in future if I become anaemic again due to donating.
https://www.bbc.co.uk/news/articles/c98p0pj7dypo