I've been trying to get assessed for POTS since August! (And yes, Sally is one of the people who made me aware of it in the first place. I dropped her a PM via PR, since I can't use the messaging system here yet.) It is going slowly, there have been snafus along the way, but the appointment with the cardiologist is now less than a month away, and hopefully he will be able to refer me to a really good ME and POTS specialist in another part of the country whom I want to see.

I just had a chat with the people who make my D3 supplement and they reckon that the amount of D3 I'm planning to take sounds like a good amount. The plan is three of the Opti3 capsules a day, which will be 300iu per day, plus two of the 5000iu D3 capsules a week. That averages out to 1729iu per day. If I made it three D3 capsules a week, it would be 2443iu per day. Would that be better?

So is my D3 17ng/ml, then? The range my doctor is using definitely seems to be on the low side, from having had a look around.

What's your preferred reference range for B12?

Incidentally, I've been hearing that you need to take more potassium when you increase your B12 levels, but then I looked up B12 on Wikipedia (which backed up your assertion that sublingual is pointless, there was a handy 2003 study) and it said that potassium can actually interfere with B12 absorption. Any thoughts? I'm taking about 1/2tsp potassium chloride a day in my electrolyte drinks (well, I call them that, it's just low-sodium salt in water).

With regard to increasing the B12, any idea how I work out how fast to increase it? Are there symptoms which would be a sign to slow down, for instance? I tried it in the morning for a few days, felt really tired all day, switched to evening, couldn't get to sleep, so I have no idea when to take it now. I gather that chewing the tablets is a good idea, plus the empty stomach thing. Although on that subject, does it matter if I've recently had a small snack, such as an oatcake or two? Once I'm on a higher dose, is it better to take it all at once, or in divided doses throughout the day?

Angioedema - I'm not getting any swelling, which seems to be an important part of that. My skin looks perfectly normal, it's just itching a great deal. I've only ever had a rash once, which is when I generally got a slew of symptoms one day after lunch, which in hindsight I suspect was mild anaphylaxis. And that was six months ago anyway. Itching, on the other hand, is an everyday occurrence, along with dizziness, feeling freezing cold and so forth.

There has been one change in terms of detergents. I added a fabric softener which supposedly didn't have any artificial fragrances about three weeks ago. I used it twice, realised something was up, rang the company, discovered that they do in fact put in artificial fragrances while indicating the opposite on the label (Trading Standards are now investigating), and promptly rewashed everything. I doubt that would still be affecting me now, and I was moderately itchy before that happened anyway. Apart from that, I'm using exactly the same products I've been using for many years. I have literally been on the same shampoo and conditioner for 19 years now! I have incredibly fussy skin, so I'm always really careful about this sort of thing, make my own moisturiser and so forth.

Pabb - Sorry, I forgot to say that I went back on the gluten in order to get tested for coeliac. I think it was 6 weeks beforehand? So by the time I had the tests, I'd realised that I felt exactly the same as I did off gluten. As for gall bladder issues, they seem to be common in pretty much everyone! Which makes it hard to work out what is actually causing them.

Thanks again for all the help. I really appreciate it.