However, it seems with ITP- which is an autoimmune condition I have just been diagnosed with- it can (amongst other things) occur if there is low Vitamin B12 in the diet.
As I am a vegetarian (and B12 is not present normally in non-animal foods) I am making sure I have Marmite (fortified with B12), milk products and eggs in my diet each day (B12 is water-soluble and cannot be stored in body fat).
Fortunately, I am a lover of Marmite!
I'm sure it cannot hurt for us to have freshly-prepared food anyway if we are diagnosed with CD & want to avoid any more of these pesky conditions.
I think CUK & other authorities say if you have one of these conditions -eg CD then -you will be more likely to have others.
If it is 'in the genes' then I suppose there is not much we can do to avoid developing them (apart from avoiding too much stress, perhaps, but GFD is always a bit stressful anyway, I think!).