Hi everyone! My gastroenterologist doesn’t believe I have b12 deficiency (b12 serum levels high due to injections). He suggested the Schillings test to determine if I do. I have just learned of this test. Would it be accurate if Ive been injecting with b12 for a few weeks? Is this test sensitive and specific for P.A.?
Thanks everyone!
Are you in the UK?
So far as I am aware, the radioactive B12 required to perform the Schilling test is simply not available in the UK. (And I doubt it is readily available anywhere else.)
I suggest that your gastroenterologist might not be as up to date on B12 issues as you would wish.
(The story I read is that the manufacture of the required substance used a beef derivative and the BSE crisis caused it to disappear from the UK market. And it has never returned.)
Interesting. I’m in the US, so may be available here, or my gastroenterologist is just unaware. Thx helvella!
I do not know who you should turn to. Maybe a haematologist rather than an out-of-date gastro? 
350e: The Schilling Test
Henry J. Binder
INTRODUCTION
The Schilling test is performed to determine the cause of cobalamin malabsorption. Unfortunately, this test has not been available commercially in the United States for the last few years. Since an understanding of the physiology and pathophysiology of cobalamin absorption is very valuable in enhancing one’s understanding of aspects of gastric, pancreatic, and ileal function, discussion of the Schilling test is provided as supplemental information to Chap. 349. Because cobalamin absorption requires multiple steps, including gastric, pancreatic, and ileal processes, the Schilling test also can be used to assess the integrity of the organs involved in those processes.
accessmedicine.mhmedical.co...
This is the 19th edition copyrighted 2015.
That’s another issue. I can’t set an appt with a hematologist because my labs appear normal (serum b12 and iron) even though my cells are smaller than normal (microcytic) and have been anemic due to iron deficiency (currently on iron supplements). Hence trying to figure out things on my own. However I’ll continue searching for a GP that understands my condition..so far it’s been difficult.
I also had one 'inclusive' that was followed up a few weeks later. My understanding of it being no longer in use is because of the long half-life of the cobalt isotopes.
The Schilling test isn't widely available anymore - it is a very accurate test for diagnosing the cause of a B12 deficiency. If you can get it then go for it ... but don't be surprised if your gastro finds out that it isn't available anymore.
History lesson time, from a retired scientist, not a medic, and as usual, it's a bit long-winded.
The 'Schilling Test' was a series of tests which investigated the ability of the gut to absorb B12, using a B12 source which incorporated a radioactive isotope of Cobalt. (Cobalt is the metal ion in the B12 molecule.) Cobalt has numerous radioisotopes, and each gives a different emission spectrum so it's possible to distinguish between them in an analyser used for measuring radioactivity. Consequently it was possible to perform two tests simultanteously; using B12 [unbound to IF] and using B12 bound to [I think] bovine IF, because we used two different isotopes. The test assumed that the subject was 'B12 replete' before it was performed; it wasn't [or shouldn't have been] performed when someone was deficient. In addition, when the test was performed, a [cold, non radioactive] B12 injection was administered, to ensure that the transcobalamins were saturated. Consequently, any B12 absorbed from either capsule would be 'flushed out' in the [24 hour] urine sample, which was collected and returned to the hospital laboratory for analysis. Any unbsorbed B12 would be excreted faecally. It was an elegant test, if somewhat long-winded. It was not suitable for large numbers of tests. The potential for error remained. The possibilities included
1. that the subject was not B12 replete, and consequently the absorption from the gut could be compromised;
2. that the peak excretion of urinary B12 would be missed because the patient may not have been adequately briefed on the importance of compliance;
3. that the 'flushing dose' was not administered, resulting in the absorption and utilisation of the radioactive b12, rather than 'short circuit' excretion.
All of this is of historic interest only, because the test became unavailable a long time ago, and whilst it was of great diagnostic use, in practice it wasn't entirely infallible.
However, it's worth noting that the result was only reliable if effective treatment had been commenced several weeks before the test was performed. It's a pity it's consigned to history; we liked it as a test, but given the complications, it's probably best it stays that way.
Hi Dolansan I am in the UK.
I have had two Schilling tests - the first in 1958 which was "inconclusive" - and the second in 1972 which gave me a diagnosis of P.A.
As best as I can remember I was given a massive dose of B12 by injection and a glass full of radioactive B12 in water to drink and had to "catch" every drop of urine in a container over a period of 24 hours which was then returned to the hospital for analysis.
I have no idea why the first test "failed" as the I was probably B12 deficient in 1968 as that was nine years after having had two thirds of my stomach removed due to a burst peptic ulcer at the age of 17.
I am so pleased that my then doctor didn't "give up" on me as by four years later in 1972 my symptoms were so bad that she sent me for a second "unheard of" Schilling test that was positive for P.A.
When I attended the surgery for the results my doctor asked whether I wanted the good news or the bad news. I asked for the bad news and she said that I was going to die within two years. I was a 30 year old father of two daughters under six with a wife with heart problems.
So what's the good news? I asked and she said that I wasn't going to die if I either ate raw liver three time a day, or had cyanocobamalin B12 injections every month for the rest of my life.
Now I love liver - with onions and gravy but chose to have the injections and I'm still "clivealive" after over 48 years and am now at the age of 79.
I wish you well.
Wow. Thanks for sharing! I’m glad your doing well now
Hi Clivealive! If you happened to be B12 deficient when the first test was done in 1958, then that would probably explain the inconclusive result. It's always interesting to hear 'war stories' from those who were there. Thank you. The later DiCoPac test was much easier to administer, b ut worked exactly the same way.
I remember the difficulty I had with strapping that huge plastic container full of urine sloshing about on the back of my motorbike. I guess anyone who saw it might have thought it was a "reserve" petrol tank
My wife Valerie used to say that I "glowed in the dark" after the test but I'll not go into that now
Goodnight from the UK.
Same experience as Clivealive- Schilling test in 1998, which proved conclusively that I had PA. I can remember the 'embarrassment' of toting two huge plastic containers to the hospital lab, containing my urine collection for the previous 24 hours! I had them in carrier bags to disguise them! Cover blown when the receptionist announced loud and clear 'another urine collection for you' to the lab chap!
I don't know why we should have felt embarrassed - everyone does it - one way or another - we didn't have plastic carrier bags back in 1968/72
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