Vitamin E

Question 1

What are the 8 Vitamin E compounds?

Answer 1

• 4 tocopherols ( alpha, beta, gamma, delta)
• 4 tocotrienols (alpha, beta, gamma, delta)

They all have varying degrees of bioactivity

The body’s most preferred form is alpha tocopherol

Natural form is more potent that synthetic form

Question 2

How is Vitamin E absorbed?

Answer 2

Absorbed passively

Amount absorbed depends on how much fat is eaten with it, ranges from 20-70%

Question 3

How is Vitamin E transported around the body?

Answer 3

• Via micelles into the enterocyte
• Via chylomicrons through the lymphatic system
• Via lipoproteins from the liver to the cells

Question 4

Where is Vitamin E stored in the body?

Answer 4

90% in adipose tissue

Question 5

How is Vitamin E excreted from the body?

Answer 5

Urine, bile and skin

Question 6

What are the functions of Vitamin E?

Answer 6

• Main function is as an antioxidant and preventing the propagation of free radicals
• Alpha tocopherol stabilises peroxyl radicals by donating an electron, and prevent the lipid oxidation chain reaction

Question 7

What causes Vitamin E deficiency?

Answer 7

• malabsorption
• increased requirements for smokers
• genetic defects of transporters

Question 8

What are the risks of Vitamin E toxicity?

Answer 8

High doses of vitamin E interfere with the clotting ability of Vitamin K and so causes blood thinning and risk of haemorrhages

Question 9

What are good sources of Vitamin E?

Answer 9

• Sunflower seeds
• Avocado
• Almonds