I have some semi-regularly to keep an eye on IBD & the medication I take but that's just things like a special test relating to the medication, FBC, CRP etc.. and more recently checking whether I need more Iron, B12 and folate.
Have been starting to get into supplements recently - used to just have cod liver oil and considered multivitamins to be pointless things that just create expensive pee for most people or a sub-optimal cope for people with bad diets. Now that I have a condition that means I might actually be deficient of some vitamins despite a reasonable diet etc.. then multivitamins, for me, might actually be useful.
I guess the thing is a) the various blood tests I have done I don't necessarily get to see - it's annoying that this sort of info isn't just generally available to patients. I might have the latest one reported in a copy of a letter from a consultant to my GP or I can ask for the latest one perhaps etc.. but it would be good to see them all over time, especially if I'm going to be proactive and aim to supplement iron say on an ongoing basis.
I guess it would be interesting to know what the levels of other vitamins and minerals are like in my body too - I don't know if some of this might get into pseudoscience if some things regularly fluctuate and so aren't useful to just look at a spot measurement of on a given day, but it would be interesting to get a blood test and get a complete breakdown, see if there are some deficient areas that are way too low and then supplement etc.. and monitor every so often with new tests. I can proactively avoid getting a deficiency, feeling super tired and drowsy by early afternoon, then having several weeks of taking some high-strength iron tablets or worse going to hospital for a bag of iron into my veins then that seems like a good idea and if I've been deficient in that area then I'd like to check up on some other areas that perhaps don't have as big an impact immediately but which might not be a good thing in the long run.