Alkaline Phosphatase

Alkaline phosphatase (ALP) is an enzyme found in the body that plays a crucial role in various physiological processes, including bone mineralization and liver function.

What is Alkaline Phosphatase?

Alkaline phosphatase is a hydrolase enzyme that catalyzes the removal of phosphate groups from molecules. It is produced in several tissues, including the liver, bones, kidneys, and intestines.

Functions of Alkaline Phosphatase

  • Bone mineralization: ALP helps to deposit calcium and phosphorus into bone tissue, making it essential for bone growth and development.
  • Liver function: ALP is involved in the transport of bile salts and other substances across cell membranes in the liver.
  • Intestinal absorption: ALP helps to absorb nutrients from food in the small intestine.

Alkaline Phosphatase Test

The alkaline phosphatase test is a blood test used to measure the level of ALP in the blood. It is commonly used to diagnose and monitor conditions such as:

  • Bone disorders, such as osteomalacia or Paget's disease
  • Liver diseases, such as hepatitis or cirrhosis
  • Bone cancer or liver cancer

Normal Levels of Alkaline Phosphatase

The normal range for alkaline phosphatase levels in the blood varies depending on age and sex. In general, the normal range is:

  • Adults: 30-120 U/L
  • Children: 50-300 U/L

Elevated Levels of Alkaline Phosphatase

Elevated levels of ALP in the blood can indicate a range of conditions, including:

  • Bone disorders, such as osteomalacia or Paget's disease
  • Liver diseases, such as hepatitis or cirrhosis
  • Bone cancer or liver cancer
  • Pregnancy
  • Growth spurts in children and adolescents

Decreased Levels of Alkaline Phosphatase

Decreased levels of ALP in the blood can indicate:

  • Hypophosphatasia, a rare genetic disorder
  • Malnutrition or vitamin D deficiency
  • Certain medications, such as antacids or phosphorus-containing compounds

Article last updated on: 15th June 2025.
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