Best Vitamins

A.Penny.Saved

Based upon what you believe would help you, I would recommend Methylcobalamin which is the active form of B12 and is much better absorbed and used by the body especially in a good quality sublingual form. 1mg/1000mcg is quite a high dose and 5mg/5000mcg tablets are available.

Be very careful when supplementing Vit D because it can affect calcium and cause calcium to be deposited in the wrong places. Vit K should be added as well to help prevent calcium being deposited in the arteries etc. You want it going to your bones. Vit D3 is the preferred type of vit D rather than D2 which is often added to Cod Liver Oil after it is processed which removes the Vit A and Vit D.

Higher dose of B12 might help your IBS because it can stimulate the activity of the body's TH1 suppressor T-Cells which can be helpful in some IgE autoimmune illnesses. It depends a lot on the antibodies involved. A food allergy test such as a skin !!!!! test to show IgE reaction to food might indicate if it could be helpful.
http://en.wikipedia.org/wiki/Vitamin_B12#Medical_uses