Reference Range

Vitamin E is a fat-soluble vitamin that acts as an antioxidant and free-radical scavenger in lipophilic environments. Vitamin E requires bile for absorption, and 25% of it is absorbed orally. The vitamin is stored in adipose tissue, liver, and muscle.

The reference range of vitamin E in adults is 5.5-17 µg/mL. In children, it is 3-18.4 µg/mL.^{[1, 2, 3, 4, 5]}

Interpretation

Conditions associated with vitamin E deficiency (< 3 µg/mL in adults; < 1.5 µg/mL in infants) include the following:

Motor and sensory neuropathy
Intestinal fat malabsorption (bowel disease, pancreatic disease, chronic cholestasis, celiac disease, cystic fibrosis, short-bowel syndrome, abetalipoproteinemia, intestinal lymphangiectasia)

Vitamin E toxicity (>40 µg/mL) may be associated with the following:

Increased all-cause mortality
Heart failure
Coagulopathy (easy bruising or bleeding; prolonged PT, aPTT; inhibition of platelet aggregation)
Impaired immunity
Constitutional and gastrointestinal symptoms (nausea, gastric distress, abdominal cramps, diarrhea; headache; fatigue; muscle weakness)

Collection and Panels

Specifics for collection and panels are as follows:

Specimen type: Blood serum
Container: Vacutainer, red top
Collection method: Venipuncture
Specimen volume: 0.5 mL
Other instructions: (1) fasting specimen (for infants, draw prior to next feeding) and (2) send specimen tube in light-protective container

Related tests: Vitamin A, beta carotene

Description

Severe deficiency, as may occur in persons with abetalipoproteinemia or fat malabsorption, profoundly affects the central nervous system and can cause ataxia and a peripheral neuropathy resembling Friedreich ataxia.

While in most healthy adults, short-term supplementation with up to 1600 IU of vitamin E appears to be well tolerated and to have minimal side effects, long-term safety is questionable. Data suggest a possible increase in mortality and in the incidence of heart failure with long-term use of vitamin E (400 IU or more) in patients with chronic diseases. Therefore, an upper limit of 1000 mg/d may be too high.

A prospective study by Lawrence et al found some evidence that higher serum levels of vitamin E reduce the risk of prostate cancer. Specifically, the investigators reported that the prostate cancer risk was lower in men with a high baseline vitamin E serum level who underwent vitamin E supplementation. No association was found between three vitamin E–associated single nucleotide polymorphisms (SNPs) evaluated in the study and prostate cancer risk. The study was conducted in Finnish males who smoked.^[6]