Hi Sandy, 
I doubt that many people here monitor their potassium levels or ketone
bodies or fasting glucose. However, low potassium is a concern when in
ketosis because there is a significantly greater chance of developing kidney
stones. They are very painful and usually very easy to avoid through the
liberal use of sea salt. People who take some types of diuretics are also at
risk of low potassium and kidney stones. Monitoring potassium levels is also
important because too much potassium can be deadly. 

Monitoring ketone bodies and fasting glucose each day would provide warning
to people who are inclined to ketoacidosis. This is rarely the result of
being in ketosis, but when a person is experiencing depleted production of
insulin, they will tend toward ketoacidosis. I have had the unfortunate
experience of working with someone who developed ketoacidosis on the
ketogenic diet. It was a frightening experience and I was responsible
because I charge for my consultation time when I work with people to lose
weight. It was a lesson that I try to share with others. 

Ketoacidosis is rarely a problem in the context of the ketogenic diet but it
is wise to protect against that risk. If you have been eating Paleo for
yearss or even many months, you are safe from ketoacidosis. Kidney stones is
another question. Unless you are getting potassium from somewhere, you are
more likely to develop kidney stones.  

Best Wishes, 
Ron