Before I connected my symptoms with hormones, I wondered whether B12 deficiency was the cause - it is very common in Crohn's patients because of malabsoption issues.
I started taking supplements before having my blood checked, which of course skewed the result - I actually came back as having too much B12, which is misleading because in my case, it doesn't show what B12 is being absorbed, only what's available in the blood stream. In actual fact, B12 is water soluble so your body excreted what it doesn't need.
I take Solgar sublingual B12, as well as a B complex and extra B5 for adrenal support. (You should take all the B's together, not just one sort). I also take high dose vitamin C and gentle iron tablets.
Advise your GP that you are taking supplements before they test, and ask for a full print out of your results with reference ranges - I have learnt from research that "normal" is not necessarily optimum, and you may still need to supplement to feel better.