I read on webMD quotes:
"If you have uncontrolled diabetes, ketosis can become dangerous when ketones build up. High levels lead to dehydration and change the chemical balance of your blood. It becomes acidic and can cause a coma or death.
People with diabetes can get ketoacidosis, or diabetic ketoacidosis (DKA), when they don't take enough insulin. They can also get DKA when they're sick or injured or they don't get enough fluids and become dehydrated.
Some people without diabetes can get ketoacidosis, too. It's caused by alcoholism, starvation, or an overactive thyroid. A healthy low-carb diet shouldn't cause a problem"