Vitamin B12 test variation over time

[somerandomperson]

Hi All

I'd be interested to know if anyone else has had major variations in their B12 blood test results over time (I'm speaking years here). I'm obviously aware that diet and other factors change over time and there can be variation in lab equipment, but I just found out that my test that was done in 2011 was 242 ng/L but my April 2017 result was 660 ng/L (200-700), which seems like a huge difference.

Kind regards

[Gambit62 Administrator]

did you supplement at all in that period?

generally serum B12 results would be expected to vary by +/-20% just because of the limitations of the serum B12 test.

I get the impression that generally the body will regulate levels around this. Pregnancy will lower results (one reason why interpreting serum B12 during pregnancy is so difficult). There are also a few problems that can result in B12 levels building up - liver and kidney problems - and supplementation can also result in rising levels.

Generally people with absorption problems would expect to see levels reducing as stores from the liver are used up.

[somerandomperson in reply to Gambit62]

Not that I remember, but I was training very hard and taking various carb and protein supplements, so I might have been unwittingly taking b12 too. I had another blood sample taken today, so I'll know early next week what my current level is.