Hi Rudy
Welcome to NT.

Did you just start on the Thyronorm 50mg (aka Levothyroxine Sodium) or have you been taking it for a while? If you've just started it can take a bit of trial and error to find precisely the right dose. With Thyroxine just a slightly too high or too low dose can cause side effects.

Thyroxine can also accumulate over time - have you had your thyroid tested regularly since starting it - if you are able to, maybe compare result levels over time. This is something you could discuss with your PCP. If you're taking the Orlistat because of weight gain caused by the Thyronorm this may be an indication that your Thyronorm dose is too high.

In regard to the B12 it would be unusual to react to a high dose injection but not impossible - you may tolerate an oral (or sub-lingual) Methylcobalamin B12 tablet better. Start with 5mg (5000mcg) daily for 3 mths then reduce to 1000mg. Retest after 3 mths (stop the supplement at least 1 week prior to test - can give a false high result). Take on an empty stomach about 1 hour before food. Also the range you quote: 211-800 - I'm guessing this is the US pg/mL - the lower level is considered outdated by many physicians - 400pg/mL is the new low level to aim for.

Here's a link to the B12 sticky:
http://neurotalk.psychcentral.com/thread85103.html

With the D3 - I take 50,000 units 1x monthly - your body does store it. It may be that your doctor wants to rebuild your stores quickly?

All the best for getting your symptoms sorted. Feel free to ask more questions or just peruse the various forums.