Vitamin D effects a lot of thing and liver enzymes (depending on which ones) can be anything from medications, , (including OTC) to a gallstone or 1,000,000 other things. you need to continue following up with your doctor(s) - and get off of the internet! It can be harmful then good. The liver filters the blood - can be a ton of things!
Also, low potassium levels cause muscle cramping & twinges. It is normally run in routine blood exams. Talk to you doctor!