Vitamin E

Vitamin E is an antioxidant: It protects cells against damage by free radicals, which are reactive by-products of normal cell activity.

Vitamin E Deficiency

Consuming a low-fat diet may reduce consumption of vitamin E, because vegetable oils are the main source of this vitamin. Disorders that impair fat absorption can also reduce the absorption of vitamin E and increase the risk of vitamin E deficiency. Newborns have a relatively low reserve of vitamin E, because only small amounts of vitamin E cross the placenta. Thus, newborns are at increased risk of a vitamin E deficiency.

Vitamin E deficiency is rare among older children and adults. Symptoms may include reduced reflexes, difficulty walking, loss of coordination, loss of position sense (knowing where the limbs are without looking at them), and muscle weakness.

Premature infants who have a vitamin E deficiency are at risk of several serious disorders. They may develop a form of anemia in which red blood cells rupture (hemolytic anemia). Other disorders include bleeding (hemorrhage) within the brain and retinopathy of prematurity, in which blood vessels in the eyes grow abnormally (see Section 23, Chapter 264).

Blood tests to detect vitamin E deficiency are not routinely available. Treatment involves taking vitamin E supplements by mouth.

Vitamin E Excess

High doses of vitamin E may increase the risk of bleeding (including hemorrhagic stroke in adults), particularly for people who are also taking an anticoagulant (especially warfarin). Premature infants may be given high doses to reduce the risk of retinopathy. Occasionally, adults who take very high doses develop muscle weakness, fatigue, nausea, and diarrhea.

The diagnosis is based on the person's circumstances and symptoms. Treatment involves discontinuing vitamin E supplements. If necessary, vitamin K is given to stop bleeding.