high levels of themselves aren't dangerous but high levels can be sign that something else is going on, eg problems with kidneys or liver. As fbirder says the thing to do is to speak to GP so that possible causes can be ruled out.
The good news is that using B12 as an indicator could be a way of catching anything nasty very early on and dealing with it before it really becomes a problem.
This article - few years old now - suggested using high B12 as a way of monitoring for some problems.
1107 (or 808 pmol) is not sooo high. If I remember correctly above 1000 pmol (or it could be 1200) is reason for further investigation. You might also been getting extra B12 without knowing it like some cereals have it added, grain/nut-milks, vegan products etc etc. Just have a think if anything applies, and you could always ask to retest if you are worried but most likely you are just one of those people that absorbs it well.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.