Hi. Welcome to JustAnswer. I shall try my best to assist you while you are corresponding with me.
Iron deficiency can be due to an inadequate diet, loosing iron somewhere or an inability to absorb and store iron.
From the information you have provided, it does not seem that your diet is inadequate.
And since you have replenished lost stores with oral iron replacement therapy, absorption does not seem to be it either.
It is thus, evident that you problem might be loss of iron. The most common cause of iron deficiency via this channel is bleeding, since haemoglobin contains iron and people who bleed from somewhere chronically develop iron deficiency anemia.
And when bleeding is concerned it is not about iron replacement but rather to stop the underlying process i.e., bleeding.
If you have abnormal menstrual bleeding or stomach upsets like gastritis or ulceration causing black tarry stools then they need to be treated.
For as long as you keep loosing iron, replacement will be required. But once, the loss is controlled, the stores will be replenished themselves.
I would suggest that you visit an Internist rather than a Trichologist and have a complete evaluation done.
Once the underlying cause is pin pointed, treatment can be initiated and your problems solved.
Please reply back or interact so that we can proceed.
It was a pleasure.
Are you seeing your internist for this?
As in on the site?
Yes, does NHS or an insurance cover you?
I don't have much experience in the UK health system. But I am sure, referral is possible via NHS.
After all, this needs to be evaluated. You will have to be proactive with your GP about this and demand for a referral.
If you have black tarry / jelly like stools then it is definitely your upper GI tract.
But if not that, then your menstrual irregularity is reason enough to cause iron deficiency.\
It is fairly simple to judge and a few questions are enough. A full blood count, iron levels, TIBC, ferritin levels, liver function tests and a stool test for occult blood are the tests required initially.
Yes, that is the best thing to do.
And thank you. :)