Human Nutrition 3(3+0)

Lesson 22 : Vitamin E

Introduction

• Vitamin E comprises a family of eight naturally occurring compounds: four tocopherols and four tocotrienols, of which alpha-tocopherol is the only one to have vitamin-E activity in the human body. It is also the most common form of vitamin E in food.
• The chemical name of vitamin E, tocopherol, is derived from toco, meaning "related to childbirth."
• The link between vitamin-E deficiency and reproductive failure in rats was first discovered in 1922 by Herbert Evans and Katherine Scott Bishop.
• Vitamin E acts as an antioxidant, protecting vitamins A and C, red blood cells and essential fatty acids from destruction.
• Vitamin E is highly susceptible to destruction by oxygen, metals, light, and deep-fat frying. As a result, prolonged food storage lowers the vitamin-E content of food.
• The requirements and functions of vitamin E are dependent on the quantity of polyunsaturated fatty acids present in the tissues and selenium status of the animal.