I Would be asking questions. 300mcg does seem to me to be a very large dose. (Are you sure it was that much?)One of the things we all learn, (and you seem to be proactive in this regard, ) is that we each need to learn as much as we can about our disease, symptoms and treatments. Having done so, we then need to ask questions Before allowing anything to be administered.My understanding of the relationship between Hb and hydration agrees with yours. What I would say though, is that if you were indeed dehydrated, then your actual Hb may well have been lower than 9.