Question 1

Vitamin E deficiency causes xerophthalmia, irreversible blindness due to hardening of the cornea.

Accepted Answer

The answer of Vitamin E deficiency causes xerophthalmia, irreversible blindness...

Question 2

Vitamin A deficiency is a severe public health concern in developing nations, often resulting in blindness and death due to infection.

Accepted Answer

Vitamin A deficiency can lead to blindness and increased susceptibility to infections such as measles and diarrhea, resulting in increased morbidity and mortality, mostly in developing countries.

Question 3

Excessive consumption of vitamin A supplements can be highly toxic.

Accepted Answer

Excessive consumption of vitamin A supplements can lead to toxicity, with symptoms including headache, dizziness, nausea, fatigue, loss of appetite, skin irritation, and hair loss. Chronic toxicity can lead to liver damage, bone fractures, and even death. It is important to follow recommended daily intake guidelines and consult a healthcare provider before taking any supplements.

Question 4

Only the retina's rod cells, and not its cone cells, require retinal.

Accepted Answer

Both rod and cone cells require retinal, as it is a key component of the photopigments in both types of cells, essential for the phototransduction process.

Question 5

Cooking foods high in carotenoids improves their bioavailability.

Accepted Answer

Cooking foods high in carotenoids, such as carrots and spinach, breaks down the cell walls and enhances the release of these antioxidants, making them more available for absorption by the body.

Question 6

Selenium toxicity occurs from an overconsumption of foods rich in this mineral.

Accepted Answer

Selenium toxicity is rare and usually occurs from excessive intake of supplements, not from dietary sources of selenium. Foods that are high in selenium include Brazil nuts, seafood, organ meats, and whole grains. It is recommended to consume these foods in moderation as part of a balanced diet.

Question 7

Beta-carotene is a precursor of retinol.

Accepted Answer

This statement is true. Beta-carotene can be converted into retinol, which is a form of vitamin A, in the human body.

Question 8

Scurvy is the deficiency disease associated with inadequate vitamin C intake.

Accepted Answer

Scurvy is indeed the deficiency disease associated with inadequate vitamin C intake.

Question 9

Vitamin C is not stored in the body and must be consumed frequently.

Accepted Answer

Since humans do not have the ability to produce Vitamin C, it must be regularly consumed in the diet or as a supplement. Vitamin C is water-soluble and any excess amounts are excreted by the body, which means that it is not stored in the body.

Question 10

Toxicity symptoms of vitamin A include birth defects, spontaneous abortion, blurred vision, and liver damage.

Accepted Answer

Vitamin A toxicity can cause birth defects, spontaneous abortion, blurred vision, and liver damage. It is important to not exceed the recommended daily intake of vitamin A to prevent these harmful effects.

Question 11

A free radical is highly unstable because it has unpaired electrons in its outermost shell.

Accepted Answer

Free radicals are highly reactive because they have unpaired electrons in their outermost shell, which makes them seek out other molecules to pair with and become stable. This also makes them highly unstable and potentially damaging to other molecules in their vicinity.

Question 12

Selenium is found only in animal products.

Accepted Answer

Selenium is a chemical element found in both animal and plant-based foods, including Brazil nuts, whole grains, seafood, and some fruits and vegetables.

Question 13

Ninety percent of the vitamin A we absorb is stored in adipose tissue.

Accepted Answer

While vitamin A is stored in various tissues in the body, including the liver and kidneys, only a small portion (around 1-2%) is stored in adipose tissue. The majority of vitamin A is stored in the liver.

Question 14

Carrots, spinach, and sweet potatoes contain a large amount of preformed vitamin A.

Accepted Answer

Carrots, spinach, and sweet potatoes contain beta-carotene, which the body can convert into vitamin A, but they do not contain a large amount of preformed vitamin A itself. Preformed vitamin A is found in animal products.

Question 15

Selenium is the only mineral with a known antioxidant function.

Accepted Answer

Other minerals, such as zinc and copper, also play a role in antioxidant functions by acting as cofactors for antioxidant enzymes like superoxide dismutase.

Question 16

Diseases that cause malabsorption of fat can result in a vitamin C deficiency.

Accepted Answer

Vitamin C is not a fat-soluble vitamin and is not directly affected by malabsorption of fat. However, a disease that causes malabsorption of fat can lead to deficiencies in other fat-soluble vitamins such as vitamins A, D, E, and K.

Question 17

As beta carotene is not considered a nutrient, no RDA has been established.

Accepted Answer

The answer of As beta carotene is not considered a...

Question 18

Guinea pigs and humans are two groups that cannot synthesize their own vitamin C and must consume it in their diet.

Accepted Answer

Both guinea pigs and humans lack the enzyme necessary for synthesizing vitamin C in their bodies, so they must obtain it through their diet.

Question 19

Carotenosis is a serious side effect of consuming too much beta-carotene; it can be fatal if untreated.

Accepted Answer

Carotenosis is a condition in which excess beta-carotene accumulates in the skin, giving it a yellow or orange color. It is not a fatal condition and can be resolved by reducing intake of beta-carotene.

Question 20

A vitamin A deficiency can cause night blindness.

Accepted Answer

Vitamin A is crucial for vision, and a deficiency can lead to night blindness, which is the inability to see in low light conditions.

Quiz 8: Nutrients Involved in Antioxidant Function