Why is my B12 and folate always on lower end of normal even with injections/supplements

[thyroidorwhat]

27m, non-smoker, no drugs etc

I had been experiencing extreme tiredness for years and my blood tests were always normal. I asked that they check my vitamins and my B12 was 184 (range starting at 180+) and my folate is always borderline too. This was in 2015.

I still felt unwell and eventually had a private pernicious anaemia test which said I didn't have it, but ordered private injections to see if it would help.

There has been a small improvement over time, but even with injections my B12 has never been that high. The latest test is 260 ng/L (range 130-900 ng/L)

My folate is 4 ug/L (range >3 ug/L). I've never seen it higher than that in years of blood tests, and it's often below range. I eat a lot of veg.

I don't have pernicious anaemia, I'm injecting 1000mcg cyanocobalamin in my stomach once every few weeks and taking a b complex daily too.

I'm not actually deficient but why are my levels always on the lower side of normal even with injections and supplements? Is it possible that this is a problem?

I have meat/dairy/vegetables with every meal. I'm not experiencing weight loss or have any known physical health conditions either.

Does anyone have any ideas?

Thank you

[Nackapan]

A negative result with the intrinsic factor blood test does not rule out PA It picks uk only about 50% if thises with PA it's not a definitive test .

Atre you taking daiky folic acid?

It's recommended all young women rxjd 400mcg daily.

How often do you inject b12?

It dies seem a low level if on say 2 weekly injections.

You are obviously not absorbing enough from your greens or oral b complex.

Have you had good leves of iron and vif d too.

What does s your doctor think?

What are your symptoms now?

[Gambit62 Administrator]

after a injection your serum b12 levels will be off the scale and then they will gradually fall as excess is removed from the blood by the kidneys. If your levels are getting that low then you would seem to be on the fast end of rate of removal - whilst one month is the average for cyanocobalamin some people will remove it much faster and others much slower - so it looks as if you really need more frequent injections than you are doing .As Nackapan says - negative IFA is a long way from proving that you don't have PA - the test isn't very sensitive - though a positive is good evidence that you do have PA.

Using serum B12 levels to assess whether you are deficient or not post an injection is at best difficult and not recommended as a way of treating patients with PA in the UK by the BCSH or NICE. You would be much better off keeping a symptoms diary and using that to determine the frequency of top-ups.

Folate is more responsive to dietary intake - an absorption problem - likely if you have a B12 absorption problem - could mean that you need to take higher levels of folate in order to absorb enough. Unlike B12 the normal range for folate is a much better guide to individual folate status so if you are in range then that implies that the supplementation levels you are currently using are sufficient.