I've never had a low potassium (but I love bananas!) and it hasn't been a common thread here thru the years.
That said, certainly doesn't mean that might not be how your particular version of Lupus is acting! I need a new set of blood tests myself. Always good to make sure we've got all the basic vitamins, minerals, and nutrients covered!
Lynnwood, Lupus & Sjogren's Moderator, Dx: 2000DIAGNOSING LUPUS & HW's LUPUS 101
"Life is far too important to be taken seriously." - Oscar Wilde