It seems there are a lot of people struggling with this issue, and that generally GPs are fairly poor at appropriately addressing it. Do NOT be fobbed off by your GP telling you that iron deficiency does not matter if you dont have anaemia (low HB) This is NOT true.
I have been doing a lot of research to arm myself with evidence ahead of my next GP appointment and thought it may be useful to share some useful info here for any others in the same situaiton.
I would say, if you have low ferritin (and NICE define iron deficicency as ferritin under 30, although ideally you want to be aimin for 70-100 for optimum functioning) then you need to be proactive in getting treatment. If you dont have an identified cause (eg heavy periods) then I would also push for further investigations to identify a cause.(eg looking for causes of malabsorption, ruling out more serious causes of innternal bleeding eg FIT test, possible gastro referral etc) If you have low ferritin, but your haemoglobin level is not low then you are technically not anaemic. Drs may use this fact to tell you that therefore you shouldnt have symptoms. This is not true. Iron deficiency without anaemia can cause signifcant symptoms and stll needs treating (see papaer below for example of evidence) I would suggest also getting you folate, b12 and Vit d checked if you can.
resources which may be helpful to share with your GP:
Iron deficeincy without anaemia: a diagnosis that matters PMC
Very useful evidence to share with those GPs that claim that iron deficciency without anaemia doesnt matter!
Iron, neuro-biovailability and depression
One of the recent papers coming out discussing the link between iron deficiency and depression. Interesting read for those with iron deficicency and symptoms of low mood. This is a growing area of interest in research and clincial practice.
British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults
This guideline is for iron deficiency anaemia, but some of the info is applicable to iron deficicency without anaemia too. See particularly pages 11-14 for info on various options of iron replacement therapies.
NICE CKS topics - Iron deficiency anaemia
Again, mostly focused on iron deficiciency anaemia but still lots of info applicable to iron deficiency without anaemia (eg definition of iron deficiency as below 30ug/l)
NICE Guidance - Coeliac Disease
Useful for anyone with possible malabsortion issue suspecting possible coeliac that needs investigating.
NICE CKS topics : Anaemia - B12 and folate deficiency
For those who may also have b12 and/or folate deficiency. Again guide is specifically about anaemia but also has useful info that would be applicable to deficencies without anaemia. See esp section on scenario - management for discussion on when to refer to gastro for further investigation.
If anyone else has any evidence/articles they have come across would be great to have them added to this thread to build a bit of a resource to help others going through this!