David writes (re lice and iron):
All I remember that I know is that one time I let my cat endure a heavy flea infestation for an unconscionably long time. I redeemed myself, if at all, by the knowledge that I slept with her a lot, and so endured a share myself (but I'm extraordinarily thick skinned, so it wasn't so bad, and I didn't get plague).
Anyway, the situation's gravity was brought home to me when I discovered that she was significantly anemic. Clearing the fleas and maintaining her freedom from parasites of any kind found the anemia gone and blood restored to a normal hct, hgb after a few months. In other words, the insects consumed a significant quantity of blood.
Lice aren't fleas of course, and people are bigger than cats, so I don't know if the lady who corresponded with you about her and her daughters' lice and her longstanding iron supplementation will have her case at all illuminated by my anecdote, but I do know that fleas can drain a consequential amount of blood from some of us.
What do you think?