There are many reasons a person can experience high or low levels of alkaline phosphatase. Walk-In Lab’s ALP blood test is a convenient and cheap online solution for identifying your alkaline phosphatase levels. Causes of high alkaline phosphatase: High levels of alkaline phosphatase can be caused byhealing fracture, bone growth, acromegaly, liver or bone metastases, osteogenic sarcoma, myelofibrosis, leukemia, and rarely myeloma. Alkaline phosphatase is used as a tumor marker in the body. Sometimes seen in rickets and osteomalacia, serum calcium and phosphorus will often have low to normal levels, while alkaline phosphatase may have normal or increased levels. Hypervitaminosis D sometimes causes spikes in alkaline phosphatase Isolated elevation of serum alkaline phosphatase is often see in Paget disease of bone. Some of the highest levels of serum ALP are seen in Paget disease. With its effects upon bone, hyperthyroidism may elevate alkaline phosphatase. Evidence shows that the thyroid hormone (T3) acts to stimulate bone alkaline phosphatase activity through an osteoblast nuclear receptor-mediated process.