W7-L4: Vitamin A

Question 1

Vitamins A, E (+C) are considered what?

Answer 1

Question 2

What are the forms of Vitamin A?

Answer 2

1. Preformed Vitamin A (Retinol)
2. Provitamin A (Carotenoids)

Question 3

What is Preformed Vitamin A (Retinol)?

Answer 3

• Found primarily in animal-based foods (e.g., liver, fish oil, dairy products, eggs).
• Retinol is the active form of Vitamin A that the body can use directly for functions like vision, immune function, and cell growth.

Question 4

What is Provitamin A (Carotenoids)?

Answer 4

• Found in plant-based foods, particularly in colourful fruits and vegetables (e.g., carrots, sweet potatoes, spinach, pumpkin, and kale).

Question 5

What are Common Carotenoids?

Answer 5

• Beta-carotene is the most abundant carotenoid and the primary precursor to retinol
• Other Carotenoids: Includes alpha-carotene and lutein, though they are less efficiently converted to retinol than beta-carotene.

Question 6

What are the Functions of Vitamin A?

Answer 6

1. Vision
2. Immune Function
3. Cell Growth & Differentiation
4. Antioxidant

Question 7

How does Vitamin A play a role in Vision?

Answer 7

Critical for the formation of rhodopsin, a pigment in the retina that enables the eye to adapt to low-light conditions

Question 8

How does Vitamin A play a role in
Immune Function?

Answer 8

Enhances immune response and helps maintain the integrity of skin and mucous membranes (which act as barriers to pathogens).

Question 9

How does Vitamin A play a role in
Cell Growth & Differentiation?

Answer 9

Plays a role in growth and repair of cells, particularly in the skin, gut lining, and respiratory system

Question 10

How does Vitamin A play as an Antioxidant?

Answer 10

Acts as an antioxidant, protecting cells from oxidative stress

Question 11

What is the RDA for Vitamin A?

Answer 11

Men 900mcg, Women 700mcg

Question 12

What is the UL for Vitamin A?

Answer 12

UL: 3,000mcgs of preformed vitamin A

Question 13

What happens when we consume too much preformed Vitamin A?

Answer 13

Preformed vitamin A is stored in the body and toxic when
consumed in large or continual dosages

Question 14

What can Vitamin A toxicity lead to?

Answer 14

Toxicity can lead to very dry skin, cracks at the corners of the mouth (cheilosis), gingivitis muscle and joint pain, fatigue, depression, and abnormal liver tests

Question 15

What are symptoms of Vitamin A deficiency?

Answer 15

More common, especially in regions where diets are low in animal products and fruits/vegetables rich in carotenoids.

• Xerophtalmia or “dry eyes”
• Increased infection risk
• Poor night vision
• Stunted Growth & Development (in Children)

can also cause blindness in children