Well this is interesting. I came across an old lab test from 7 years ago, in 2004. It's the only time (as far as I know) that my B-12 level was ever previously tested.

My B-12 level in 2004 was 1627.

And my B-12 level from last month was 398.

I have taken a B-complex vitamin daily for many years, so it's not like I wasn't trying to get extra B vitamins. And I have always eaten a sensible well-balanced diet.

What would cause a woman's B-12 level to drop so dramatically in 7 years?

I've had Hashimoto's Thyroiditis for the past 15 years. Would that be the sole reason, or might there be something else?

I need to know what else to ask my endocrincologist to test me for when I see her next month.