Question 1

Which of the following is a valid reason for vitamin supplementation?

Accepted Answer

Antibiotics can disrupt the balance of intestinal bacteria, some of which are responsible for producing certain vitamins such as vitamin K and some B vitamins. This disruption can lead to a decrease in the production of these vitamins, making supplementation necessary in some cases.

Question 2

Which vitamin is the only one that is assigned hormonal status in its active form?

Accepted Answer

Vitamin D is unique among vitamins because when it is converted into its active form, calcitriol, it functions as a hormone. This active form of Vitamin D helps regulate calcium and phosphate levels in the body, which are crucial for maintaining healthy bones and teeth.

Question 3

Vitamin B6 is a collective term for three naturally occurring substances that are all metabolically and functionally related. Vitamin B6

Accepted Answer

Vitamin B6 plays a crucial role in the metabolism of protein, carbohydrates, and fat, aiding in the conversion of food into energy and helping in the synthesis of neurotransmitters.

Question 4

Vitamin intake may be inadequate for which of the following reason(s)?

Accepted Answer

A diet high in processed foods often lacks essential nutrients, including vitamins, because processing can remove or destroy them. Proper preparation can sometimes mitigate this, but many processed foods are inherently low in vitamins. Choices B and C are incorrect because storing fruits and vegetables at room temperature in direct light can actually lead to vitamin loss, and cooking with a microwave or in waterless cookware does not necessarily result in excessive vitamin losses; in fact, these methods can help preserve vitamin content by reducing cooking times and the need for water.

Question 5

Which of the following is true of the vitamin known as niacin?

Accepted Answer

Niacin, also known as vitamin B3, is essential for converting food into energy, playing a significant role in energy metabolism.

Question 6

Which of the following are fat-soluble vitamins?

Accepted Answer

Vitamins A, D, E, and K are fat-soluble, meaning they can be stored in the body's fatty tissue and liver.

Question 7

Which of the following are true B vitamins? (1) inositol (2) choline (3) biotin (4) lipoic acid (5) PABA (6) niacin (7) bioflavinoids (8) ubiquinone (9) vitamin B6 (10) thiamin (11) laetrile (12) pantothenic acid (13) vitamin B15 (14) vitamin P (15) vitamin B17

Accepted Answer

Biotin, niacin, vitamin B6, thiamin, and pantothenic acid are true B vitamins.

Question 8

Which of the following statements regarding vitamin deficiency is NOT true?

Accepted Answer

Subclinical malnutrition does not always impair physical performance. It refers to a nutritional deficiency without overt clinical symptoms, meaning that physical performance might still be maintained despite the deficiency.

Question 9

Which of the following vitamins has no UL listed?

Accepted Answer

Vitamin B12 has no Upper Level (UL) intake listed because no adverse effects have been associated with its high intake from food or supplements in healthy individuals.

Question 10

Which of the following statements is correct for vitamin supplements?

Accepted Answer

A megadose of vitamins is generally defined as an amount significantly higher than the Recommended Dietary Allowance (RDA), often ten times or more, though the exact factor can vary depending on the specific vitamin. This definition is used to describe doses of vitamins that are much higher than what is typically recommended for daily intake.

Question 11

Which of the following statements is true of vitamins?

Accepted Answer

Vitamins are essential nutrients that the body needs in small amounts to work properly and maintain health, but they do not directly contribute to the body's structure, have caloric value, or serve as an energy supply.

Question 12

Vitamin K may be obtained in our diet or formed by the

Accepted Answer

Vitamin K can be synthesized by the bacteria in the human gut, providing a source of this vitamin beyond dietary intake. Choices A and B do not accurately describe sources of vitamin K.

Question 13

Thiamine is a water soluble vitamin and

Accepted Answer

Thiamine, or vitamin B1, is crucial for the conversion of pyruvate to acetyl CoA in the metabolism of carbohydrates, which is a key step in energy production within cells.

Question 14

Vitamin C has been the subject of much controversy. Which of the following statements is true for ascorbic acid?

Accepted Answer

Vitamin C, or ascorbic acid, plays a crucial role in the synthesis of collagen, which is vital for the health of skin, blood vessels, and bones. It also participates in the production of certain hormones and neurotransmitters, making it essential for overall health. The other statements are either outdated, incorrect, or lack sufficient scientific backing.

Question 15

Which of the following is NOT true of vitamin A?

Accepted Answer

The adult female Recommended Dietary Allowance (RDA) for vitamin A is not equivalent to 6 milligrams of retinol or 1 milligram of beta-carotene. The RDA for vitamin A is usually expressed in micrograms (mcg) of Retinol Activity Equivalents (RAE), not in milligrams, and the values differ from the ones provided.

Question 16

The human body is known to need an adequate supply of______ different vitamins.

Accepted Answer

The human body requires an adequate supply of 13 different vitamins for proper functioning and health. These include vitamins A, C, D, E, K, and the eight B vitamins.

Question 17

Vitamin D

Accepted Answer

Vitamin D is crucial for bone health because it helps the body absorb calcium, thus preventing osteomalacia in adults and rickets in children, which are conditions characterized by the softening of bones.

Question 18

Cobalamin, more commonly called vitamin B12,

Accepted Answer

Cobalamin, or vitamin B12, is crucial for DNA synthesis and the development of red blood cells, but it is not abundant in plant foods, was not one of the first B vitamins discovered, and there is no strong evidence that it significantly increases metabolic functions like endurance performance when supplemented in individuals with adequate levels.

Question 19

Which of the following vitamins is NOT a fat soluble vitamin?

Accepted Answer

Vitamin B12 is not a fat-soluble vitamin; it is a water-soluble vitamin. Vitamins E, D, and A are all fat-soluble.

Question 20

Free radicals

Accepted Answer

Free radicals are highly reactive molecules with unpaired electrons that can interact with body tissues, potentially causing damage. They are linked to various health issues, including DNA damage and the development of cancer. They can be neutralized by a variety of antioxidants, not just beta-carotene or vitamin E.

Quiz 7: Vitamins: the Organic Regulators