Α-Tocopherol

Α-Tocopherol is a type of vitamin E that is preferentially absorbed and accumulated in humans. It is considered the most biologically active form of vitamin E. Α-Tocopherol is a potent antioxidant, which helps to combat free radicals in the body.

Structure and Synthesis

Α-Tocopherol is a fat-soluble vitamin with a chromanol ring and a phytyl side chain. The chromanol ring has a hydroxyl group that can donate a hydrogen atom to reduce free radicals, and a hydrophobic side chain that allows for penetration into biological membranes. Α-Tocopherol is synthesized only by photosynthetic organisms, including some types of plants and algae.

Function

The primary function of α-Tocopherol in humans appears to be that of an antioxidant. Free radicals are formed primarily in the body during normal metabolism and also upon exposure to environmental factors such as cigarette smoke or pollutants. Α-Tocopherol is able to neutralize free radicals by donating one of its hydrogen atoms, thus breaking the chain of free radical formation.

Deficiency

Α-Tocopherol deficiency is rare in humans and is usually due to genetic mutations affecting the α-Tocopherol transfer protein. Symptoms of α-Tocopherol deficiency can include neuromuscular problems such as spinocerebellar ataxia and myopathies.

Dietary Sources

Α-Tocopherol is found in a variety of foods. Good sources include vegetable oils, nuts, seeds, whole grains, and green leafy vegetables. It can also be found in meat and fish, but in smaller amounts.

See Also

• Vitamin E
• Antioxidants
• Free radicals
• Spinocerebellar ataxia
• Myopathies