Extremely high levels of serum alkaline phosphate 280 in the blood test what could it mean?

Lots of things: This can be fine for a growing child or teen, an older person with subclinical paget's (extremely common), or even someone who's non-fasting and just happens to raise the intestinal alk phos on eating. It's also normal for late pregnancy or if you have a healing fracture (you might not even know about, say, a foot stress fracture.).