B12 lower after supplementing - Pernicious Anaemi...

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B12 lower after supplementing



A few weeks ago I had my B12 and folic acid levels tested:

Folic acid 9.1 nmol/l

B12 154 pmol/l

Since then I've been taking B12 supplements, 1000 mcg a day. Last week I had my levels tested again:

Folic acid 17 nmol/l

B12 147 pmol/l

Not what I expected after supplementing. My doctor thinks it's no big deal, but by some standards I'm slipping into deficiency territory here. Does it simply take more time to get your levels back up?

4 Replies

It looks like you're not really absorbing the oral supplements. Did you tell your doctor how much you were supplementing? They really should have paid more attention to the fact that not only is your level not increasing, it's decreasing. That's an indication of lack of absorption.


what was the test and what were the ranges.

Assuming it was serum B12 the results are inconclusive as to whether there has been any change in your serum B12 levels- the test is only accurate within about 20% so if the same sample was measured several times it would give results that varied by 20% and the variation above is well within that range, so your levels could have risen but the second test is just giving results at the lower end of the margin of error.

1000mcg is unlikely to have any significant effect on raising levels if you have an absorption problem as the amount you will be absorbing is likely to be 10mcg or even less. That's going to raise levels very slowly.

in reply to Gambit62

It was indeed serum B12, so if what you're saying is correct, I shouldn't draw any conclusions from this measurement.

Also, does anyone know why my folic acid levels nearly doubled without taking supplements for it? Is that test equally inaccurate?

in reply to AmelieV12

the tests for folate tend to be more accurate - probably because the folate molecule is much smaller than the B12 molecule.

However, serum folate is much more responsive to dietary intake than B12 tends to be, so this could easily explain the variance. If the measurement is in nmol/l then the range that would be quoted is probably quite broad - think that it probably runs from around 7 to 40+ so it isn't really that much of a difference between the two measurements.

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