Long story short: About a year ago my ferritin levels were on the floor (4ng/ml, range 15-200ng/ml, I think, not sure), was prescribed ferrous fumarate and the level climbed over the course of about six months to 70ng/ml or so. Since it was at a good level my GP and I agreed that I should drop down to one ff capsule every other day.
It's now time to retest. Which would yield the most useful and / or interesting result: taking the ff right up to the day of the blood test, or stopping a few days beforehand? I can't see my GP going for two tests in a short space of time so can't do both If I were to stop taking the ff a few days before, how many days should I leave between stopping and the blood test?
I realise, now, looking at the range and the last test result, that cutting back probably wasn't warranted at the time and that I was only just where I needed to be (it looked like I was close to the top of the reference range but now I really can't trust my eyes). I'm losing quite a lot of my hair and I hadn't twigged that it might be that my ferritin was too low again (although probably in range). Still, I'd be interested to know which method would give the most interesting result.