low vit D3 levels are common sense Lack of sunlight on your skin in the peak hours of the day between 10 am and 3 pm summertime hours
working inside with a window open and sunlight in does NO good, also foods low in vitamin D under 30 is deficient and you are at 18? way low

on a sunny summer day with 40% of your body exposed and a nice afternoon walk you can get up to 40,000 IU into your system and have no ill effects for this person to tell you NOT to start with 6000 IU per day is bad
it will not hurt you have you ever gotten sick from a day out for a walk in the sun??? NO

unless you are going to drink 11 gallons of milk a day you are not getting your vitamin d3
here are some foods that contain some vitamin d3
http://nutritiondata.self.com/foods-...000000000.html

Davew41, Thanks.

I have been deficient for a long time, I guess so I will wait until I speak to my Neuro.

Oh, and by the way... strange though it might seem to you, I have often gotten sick from a day out in the sun!.... LOL! Honest.

Can't ignore this
My brother even often worked outside, it's not possible he didn't get enough sunlight.

Even though the vit D your body makes from the sunlight doesn't harm you, does not mean supplements won't. Mind, I'm not saying it will, but because vit D is a fat soluble vitamin, you don't just pee out what is too much. A wrong dosage may be harmful in people with kidney diseases, which can exist before noticing any symptoms. So, better check and talk with your doc, he/she may or may not advise you to take vit D, but that's up to the doc. He/she will also tell you your best dosages, which may be 6000 IU or something else.

What did you mean by getting sick in the sun? Because MG tends to worsen when you're warm, so if it's very obvious (15 minutes sunbathing means sudden weakness tha wasn't there before), that may be something to write down...
I get Lupus rash in the sun and extra weakness. Though I have no idea what happens now, because I avoid it because reasons above and Imuran and stuff.

Good luck at your appointment, hope it's soon?