B12 and Iron - Does 'within normal limit' really mean they are fine?

In Jan 2012 my B12 and iron were tested and were found to be within 'normal limit'. They were both at the very low end of the scale. Sorry to sound paranoid here, but do we have a similar situation with these as we do with TSH with regards to what is normal. If you are within the scale, regardless of where with regards to B12 and iron, does this mean that you are ok or if you are at the lower end of the scale might you need supplements.

I'm just about to ask if I can have B12 and iron tested again and would like to understand a bit more about them.



9 Replies

  • Very much the same!

    The bottom end of B12 is way below. And the actual serum B12 is deeply questionable. We are now seeing an "Active B12" test (available at a few private and one or two NHS labs) - this seems to be a much better way of checking B12.

    Which iron test(s) did you have? The usual ferritin test has a very low bottom end and many feel it should be very much higher.

    Do you have the numbers so you could post them?


  • hi rod i cant get that nh sactive b12 test even i am paying- wher ecan i get it private thanks P.

  • I believe the Blue Horizon B12 is now Active B12 - including the one they offer through their Home Blood Tests arm. Doing it as a home test is less expensive.

    Have a look here:



  • o thanks rod but i have done ahome test with myrios it was nightmare getting the blood out i am a brave person in many ways but hey i cant do the home bloods. could you pop round ??? lol

  • My iron stores (ferritin) and B12 were both low but in range. And yet between those two things I had a ton on symptoms that got better when I took supplements. So yes, it does matter where you are in the range.

    The ranges are probably too wide, they appear to be based on statistics (the outermost 5% of the population is considered out of range) rather than optimum levels.

    What were your results?

  • Hi everyone thanks for getting back. I don't have the numbers with me at the moment Rod, but will be able to get them in a couple of days so will report back.

    I can't recall the B12, but the iron (ferritin) if I recall was 79 and the scale was 70 - something.

    Have to say that in Jan 2012 it was just before I saw Dr S so I was really poorly and hadn't found this site. Didn't even consider that these could be a problem.

    I'll check the results and get back.



  • within normal limits-------- what a phrrse- everything is wiyhin normal limits whether it is good or bad , no wonder so many people are ill. in japan they treat our normal limted as low---... take it that you are low in it all and ask more on perniious anemia site on here...

  • I'm at the bottom end of normal for both as well, always have been, dr's wont supplement though, even though half the family had pernicious anaemia.

  • Hi Thanks for all your comments.

    Can't find my B12 result. May have left that with Dr S, but my Serum Ferritin is actually 76 and the scale 20 - 307.

    Thanks for the info on the Active B12 Rod. I'm going to try and get that done, but chances are it will have to be private.


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