Alkaline phosphatase, or ALP, is a protein found in all body tissues and plays a particularly important role in liver function and bone development. Normal ALP levels range from a low of 44 international units per liter to a high of 147 international units per liter, according to MedlinePlus. Abnormal levels can signify a severe underlying medical condition, usually relating to the liver or your bones. Certain foods can raise ALP levels, which can have an effect on ALP blood test results.
Foods rich in zinc, phosphorus and vitamin B12 help increase alkaline phosphatase levels in your body. All of these nutrients can be found in beef, poultry and seafood. Oils, such as coconut and corn, may also raise your alkaline phosphatase.
When Is ALP a Concern?
If your liver is damaged, ALP can leak into your blood. If you have symptoms associated with liver disease, such as jaundice, or you take medications that could affect your liver, your doctor may prescribe a routine ALP blood test. Other conditions that may require you to have an ALP test include:
- Alcoholic liver disease, such as hepatitis or cirrhosis
- Abnormal narrowing of the bile duct
- Giant cell arteritis, or inflammation of the lining of your arteries
- Tumor of endocrine glands
- Renal cell carcinoma or kidney cancer
What Do the Results Mean?
A higher than normal ALP reading may indicate your liver has been damaged or you have a condition that is causing increased bone cell activity. Also, eating a fatty meal if you have blood type O or B before the test can cause a high reading. Some other conditions that can cause high ALP levels are:
- Blockage of bile ducts
- Bone diseases and conditions, such as rickets and Paget disease
- Bone tumors, softening of the bones, a fracture that is healing
- Liver disease or hepatitis
- Hypophosphatasia, a rare genetic bone disorder
- Protein deficiency
- Wilson disease, caused by abnormal copper metabolism
- Zinc deficiency
If you have low ALP, eating a balanced diet, under the guidance of your health care professional, can restore your alkaline phosphatase count to a normal level.
Optimal blood levels of ALP are essential to the maintenance of healthy, strong bones. To evaluate the role of zinc on ALP production and activity, a team of South Korean and Scottish researchers conducted an animal study to measure the effect of zinc deficiency on ALP activity in laboratory rats.
In the findings published in the summer 2007 issue of Nutrition Research and Practice, they concluded that zinc is critical to ensure the levels of ALP production and activity needed to keep bones healthy. Zinc-rich foods include oysters, Dungeness crab, beef, pork, dark-meat chicken and turkey, fruit, yogurt, milk, cashews and baked beans, according to the Linus Pauling Institute.
Fats and Oils
Indian researchers conducted an animal study to determine what effect, if any, the consumption of various vegetable and fish oils had on serum levels of ALP. In an article in the March 2007 issue of Digestive Diseases and Sciences, they reported that the release of ALP into the bloodstream of laboratory rats seems to vary in relation to the makeup of fatty acids in the various oils they tested.
Cod liver oil produces the highest level of ALP secretion in test animals. However, other oils, including corn oil and coconut oil, also help to elevate blood levels of ALP.
Foods High in Phosphorus
Present in every cell of the body and essential to healthy bones, phosphorus makes up 1 percent of the human body's weight, according to MedlinePlus. It also is a key component in the makeup of ALP.
Eating foods rich in phosphorus is essential to maintaining optimal levels of ALP. Such foods include plain nonfat yogurt, skim milk, mozzarella, eggs, beef, chicken, halibut, salmon, turkey, whole-wheat bread, nuts, lentils and carbonated cola drinks, according to the Linus Pauling Institute.
A 1996 study by South Korean endocrinology researchers underlined the importance of vitamin B12 to the maintenance of healthy ALP levels and activity. Their study, published in the December 1996 issue of Metabolism, concluded that optimal dietary intake of B12 increased ALP production and activity in human bone marrow stromal osteoprogenitor cells and osteoblastic cells.
- MedlinePlus: "ALP"
- Nutrition Research and Practice: "Zinc Deficiency Negatively Affects Alkaline Phosphatase and the Concentration of Ca, Mg and P in Rats"
- Digestive Diseases and Sciences: "Intestinal Alkaline Phosphatase Secretion in Oil-Fed Rats"
- Metabolism: "Effects of Vitamin B12 on Cell Proliferation and Cellular Alkaline Phosphatase Activity in Human Bone Marrow Stromal Osteoprogenitor Cells and UMR 106 Osteoblastic Cells"
- Linus Pauling Institute: "Zinc"
- Lab Tests Online: "Alkaline Phosphatase (ALP)"
- Medline Plus: "Phosphorus in Diet"
- Linus Pauling Institute: "Phosphorus"
- Linus Pauling Institute: "Vitamin B12"