Can B12 lozenges lose potency?

[tinyelephant]

After blood tests revealed a severe B12 deficiency last year, I started taking B12 sublingual lozenges. I've been taking one a day (Seeking Health Hydroxo B12 2000 mcg). I experienced very good results and saw the vast majority of my deficiency-related issues steadily go away and stay away....until recently.

Now they are coming back.

One possibility, of course, is that there's something wrong with me. But it occurred to me that another possibility is that there is something wrong with the most recent bottle of B12 lozenges.

They look normal but maybe they somehow lost their potency. The expiration date on the bottle is 2021, but I wondered if perhaps heat or some other thing could have deactivated the B12 itself. In which case for the past 5-6 weeks I would have been essentially taking sugar pills and no B12 at all.

Has anyone ever encountered this before?

[Gambit62 Administrator]

vitamin supplements aren't covered by the same quality controls as medicines which means that there can be quite a lot of variation between content in tablets and the content on the box. This shouldn't be so much of a problem with something like B12 as it is with tablets containing plant extracts like sea kelp for iodine (which is basically impossible to ensure consistent content. However, there may still be some variation. The B12 will also decay over time which would depend upon how it has been stored.

[fbirder]

Unlikely.

Even methylcobalamin is pretty stable in the solid form. More likely a problem with the formulation.