There is still some debate whether vitamin E supplementation is necessary or not. The conflicting reports sometimes make it seem like vitamin E is not as necessary for health and wellbeing as other vitamins. However, this is untrue. Vitamin E plays an important role in the body and deficiencies will lead to a host of symptoms. Supplementation is not the only answer though. Vitamin E can easily be sourced from a number of different foods, as is the cause with most micronutrients.
What is vitamin E?
Vitamin E is a micronutrient meaning that it is needed by the human body but in small quantities. It is a fat soluble vitamin and supplements are best absorbed with food. Vitamin E actually refers to a group of compounds rather than a single compound. It includes tocopherols and tocotrienols which are substances that have a similar function in the body. However, only a few forms of these substances are biologically significant for humans.
Overall a vitamin E deficiency is rare. Therefore supplementation is usually not necessary. It is absorbed from the digestive tract and is then stored in the adipose tissue, liver and muscle cells. As yet there is no conclusive evidence that supplementation can have any significant health benefit in people who do not have a deficiency. Long term supplementation in high doses can lead to toxicity.
Function of Vitamin E
Vitamin E appears to have three main functions:
- Antioxidant activity
- Immune modulation
- Antiplatelet effect
Free radicals are produced within the body as a normal part of the metabolic process. It also bombards the body from environmental sources like air pollution and ultraviolet (UV) radiation. These free radicals can damage cells if it is not neutralized by antioidants. Vitamin E is believed to be helpful as an antioxidant activity although there is inconclusive evidence whether taking supplements will definitely be beneficial in this regard.
Studies have shown that vitamin E is able has several effect on the immune system which heightens its activity. It helps to increase the numbers of lymphocytes. Vitamin E also reduces the production of substances that suppress the immune system. Collectively this means increased immune activity to help the body more effectively fight against invaders like bacteria and viruses.
Platelets are tiny cells in the bloodstream that helps with the formation of clots when there is a break in a blood vessel. However, it can also lead to clot formation inside a blood vessel thereby blocking blood flow. Platelets may also be a component of plaques that form in arterial walls to gradually narrow the blood vessel. Vitamin E appears to inhibit the aggregation of platelets to form clots.
It is important to realize that the recommended daily allowance (RDA) includes vitamin E sourced from foods and supplementation. A balanced diet usually ensures sufficient vitamin E in a day and supplementation is not necessary. The RDA varies by age, gender and physiologic states like pregnancy. It may be denoted as milligrams (mg) or international units (IU). For easy reference, 1mg is equivalent to 1.5IU.
Dose for Children
- 1 to 3 years = 6 mg/day (9 IU)
- 4 to 8 years = 7 mg/day (10.4 IU)
- 9 to 13 years = 11 mg/day (16.4 IU)
Dose for Females
- Older than 14 years = 15 mg/day (22.4 IU)
- Pregnant women = 15 mg/day (22.4 IU)
- Breastfeeding women = 19 mg/day (28.5 IU)
Dose for Males
- Older than 14 years = 15 mg/day (22.4 IU)
Toxicity and Overdose
Very large doses of vitamin E, especially if it is sustained, can have adverse effects. Firstly it is important to understand that there are tolerable upper intake levels. This is the maximum dose that the body can tolerate and any higher levels can be dangerous. However, it is important that people keep their daily intake within the RDA which is significantly lower than the tolerable upper intake levels. These levels are as follows:
- 1 to 3 years = 200 mg/day (300 IU)
- 4 to 8 years = 300 mg/day (450 IU)
- 9 to 13 years = 600 mg/day (900 IU)
- 14 to 18 years = 800 mg/day (1,200 IU)
- 19 years and up = 1,000 mg/day (1,500 IU)
In some cases, short term supplementation may exceed these levels only when there is a very severe deficiency and the dose has been approved by a doctor. However, a vitamin E deficiency is a rare occurrence. The problem more often arises with supplementation where some supplements contain up to 1,000 IU per capsule. Furthermore vitamin E is a group of compounds and supplementing with only one of these biologically active forms can be detrimental.
Causes of Vitamin E Deficiency
A vitamin E deficiency is rare and when it does occur it usually is related to a gastrointestinal condition that affects digestion and absorption of nutrients. It usually occurs when there is a problem with the digestion and absorption of fats. Therefore disorders that affect bile secretion may also impair vitamin E absorption. The conditions where a vitamin E deficiency may occur includes:
- Chronic cholestatic hepatobiliary disease
- Cystic fibrosis
- Short-bowel syndrome
Isolated vitamin E deficiency syndrome is caused by an autosomal-recessive genetic disorder despite the absence of a malabsorption syndrome involving fats.
Symptoms of Deficiency
The symptoms of vitamin E deficiency depends on the severity and duration. The symptoms that may arise in due course includes:
– Impaired proprioception
– Muscle weakness
– Night blindness
– Severe muscle weakness- Nystagmus
– Loss of proprioception
– Difficulty swallowing
– Motor speech disorder
– Irregular heartbeat (arrhythmia)
– Difficulty moving the eyes
Severe symptoms that develop with long term vitamin E deficiency include blindness and dementia.
Foods High in Vitamin E
There are many foods that are naturally high in vitamin E. In addition some foods are fortified with vitamin E. Overall a healthy balanced diet ensures that sufficient amounts of vitamin E is acquired from foods and there is no need for supplementation. However, it is important to know which foods have high to medium levels of vitamin E in order to include sufficient quantities of these foods in the daily diet.
– Certain vegetable oils like sunflower oil and wheat germ oil.
– Nuts like almonds, peanuts and hazelnuts.
– Seeds like sunflower seeds.
– Other vegetable oils like corn and soybean oil.
– Green vegetables like broccoli and spinach.
– Fruits like avocado.
Fortified foods include cereals, fruit juices and margarines among others. Multivitamins contain much smaller quantities of vitamin E than single vitamin E only supplements. Most multivitamins do provide sufficient vitamin E to meet the recommended daily allowance (RDA).