Deficiency, lactase: Lack of the enzyme lactase in the small intestine. Lactase is needed to digest lactose, a sugar found in milk and most other dairy products and also used as an ingredient in other foods. Although most people are born with the ability to make adequate amounts of lactase, the production of lactase normally decreases with age, and there are significant differences in lactase production among ethnic groups. People of African or Asian descent commonly have difficulty digesting products that contain lactose. The most common symptoms of lactase deficiency are diarrhea, bloating, and gas. Treatment usually involves avoiding lactose in the diet or taking over-the-counter lactase supplements before eating foods that contain lactose.
- Deficiency, LCHAD
Deficiency, LCHAD: Acute fatty liver of pregnancy (AFLP) has been found to be associated in some cases with an abnormality of fatty-acid metabolism. This abnormality is a deficiency of the enzyme long-chain-3-hydroxyacyl-CoA dehydrogenease (LCHAD). The mother (and father) have 50% of normal LCHAD activity and the fetus has no LCHAD activity. The metabolic disease in […]
- Deficiency, magnesium
Deficiency, magnesium: Lack of magnesium, which can occur because of inadequate intake or impaired intestinal absorption of magnesium. Low magnesium levels are often associated with low calcium and potassium levels because these nutrients interact with each other. Magnesium deficiency causes increased irritability of the nervous system, as evidenced by spasms of the hands and feet, […]
- Deficiency, phenylalanine hydroxylase
Deficiency, phenylalanine hydroxylase: See Phenylalanine hydroxylase deficiency.
- Deficiency, protein C
Deficiency, protein C: Protein C is a protein in plasma that enters into the cascade of biochemical events leading to the formation of a clot. Deficiency of protein C results in thrombotic (clotting) disease.
- Deficiency, selenium
Deficiency, selenium: Lack of the essential mineral selenium, which can cause Keshan disease, a fatal form of disease of the heart muscle (cardiomyopathy) that was first observed in Keshan province in China and has since been found elsewhere. Treatment involves ensuring intake of the recommended dietary allowance of selenium, currently 70 mg per day for […]