Nutrition Quiz #4: Fat-Soluble Vitamins

Criteria for classifying vitamins:

-Cannot be synthesized in ample amounts in the body -Chronic deficiency is likely to cause physical symptoms -Symptoms will disappear once the vitamin level in the body is restored -Deficiency can cause permanent damage

Age-related macular degeneration (AMD):

-Free radical damage to the macula in the eye -Most common cause of vision impairment in Americans over 60 years -AMD risk and loss of vision may be reduced with supplementation. Vitamin C, vitamin E, beta-carotene. Zinc and copper.

What is vitamin A?

A family of fat-soluble retinoids. Retinol, retinal, retinoid acid.

Osteomalacia:

Adult equivalent of rickets.

How do vitamins differ in their absorption and storage?

All absorption takes place in the small intestine. Fat-soluble and water-soluble vitamins differ in: absorption and bioavailability.

Nine water-soluble vitamins:

B vitamin complex and vitamin C.

Energy production:

Biotin, niacin (B3), pantothenic acid, riboflavin (B2), thiamin (B1), vitamin B6, and vitamin B12.

Osteoporosis:

Condition where bones don't mineralize properly, muscles and bone weakness and pain.

What is vitamin D?

Derived from a reaction between ultraviolet rays and a form of cholesterol in the skin. Exposure to sunlight can synthesize the body's needs. Found in two forms: D3 and D2.

True or False: vitamins provide the body with energy.

False. Although vitamins perform numerous essential functions in the body, they do not provide energy.

True or False: antioxidants are a magic pill that will prevent aging.

False. Antioxidants serve several beneficial functions in the body, but there is no magic pill for aging.

True or False: steaming is the best cooking method to retain the vitamins in vegetables.

False. Cooking foods in a microwave oven helps retain more vitamins because of the reduced cooking time and exposure to heat.

True or False: taking vitamin supplements is never harmful.

False. Overconsumption of vitamin supplements can result in intakes above the UL. Such high intakes can in turn lead to harmful toxicity symptoms.

True or False: vitamin E helps keep bones strong.

False. The main role of vitamin E is as an antioxidant that helps protect cell membranes. However, the fat-soluble vitamins D and K are involved in bone health.

True or False: vitamin K is an anticoagulant.

False. Vitamin K actually helps blood clot, as it participates in the synthesis of several proteins involved in the blood-clotting cascade.

Blood clotting and red blood cell synthesis:

Folate, B6, B12, and K.

Protein metabolism and synthesis:

Folate, vitamin B6, vitamin B12, and vitamin C.

What are antioxidants?

Group of compounds that neutralize free radicals, helping to counteract the oxidation that takes place in cells. Includes: vitamins E and c, selenium, flavonoids, and carotenoids.

Solubility:

Influences a vitamins: digestion, absorption, transportation, storage, and excretion.

Free radicals:

Molecules with an unpaired electron.

Vitamin toxicity:

Rare, results from ingesting excess vitamins, which leads to tissue saturation. Can damage cells, sometimes permanently. Results from supplementing with megadoses of vitamins; does not occur from eating foods.

Provitamins:

Substances found in foods that are not directly usable by the body. Converted to an active form once absorbed.

What are vitamins?

Tasteless, organic compounds that are required in small amounts.

Vitamins:

The chemical structure of each vitamin is unique. Each vitamin is a singular unit. Vitamins are absorbed intact. Vitamins perform numerous essential functions. Function: regulate metabolism, help convert energy in fat, carbohydrate, and protein into ATP, and promote growth and reproduction.

Fat-soluble vitamin storage:

The liver is the main storage site for vitamin a; to a lesser extent for vitamins K and E. Vitamin D is mainly stored in the fat and muscle tissue. Can build up in the body to the point of toxicity.

True or False: carrots, winter squash, and broccoli are good sources of vitamin A.

True. Deep orange vegetables and some green vegetables are good sources of the vitamin A precursor beta-carotene, which is converted to vitamin A in the body.

True or False: Fat-soluble vitamins are bound in fatty foods.

True. Fat-soluble vitamins are often found in foods that contain fat. For example, vitamin E is found in vegetable oils and vitamin A is found in egg yolks. However, some fat-soluble vitamins are also found in fortified foods that are low in fat, such as fortified cereals.

True or False: most people can meet their vitamin needs through food, so supplements are unnecessary.

True. Healthy individuals can meet their vitamin requirements by consuming an adequate, balanced diet. However, some individuals, such as those with a specific vitamin deficiency, strict vegans, or those with dietary restrictions, may benefit from taking a vitamin supplement.

True or False: the body makes vitamin D with the help of sunlight.

True. In the skin, a compound called 7-dehydrocholesterol is converted to a vitamin-D precursor when the ultraviolet rays of the sun alter its structure.

Antioxidants:

Vitamin C and E.

Rickets:

Vitamin D deficiency disease in children.

Growth and reproduction:

Vitamins A and D.

Bone health:

Vitamins A, C, D, K.

Immune function:

Vitamins A, C, and D.

Four fat-soluble vitamins:

Vitamins A, D, E, K.

Preformed vitamins:

Vitamins found in foods in their active form. Do not need to be converted.

Fortified foods:

Voluntary addition of nutrients by manufacturers to enhance the nutrient quality of food, prevent or correct dietary deficiencies, ensure adequate intake for some individuals.

What are the best sources of vitamins?

Whole foods: fruits, vegetables, and whole grains. Rich in vitamins, phytochemicals, antioxidants, and fiber.

The primary role of vitamin E in the body is to a. prevent oxidative damage to cell membranes b. serve as a coenzyme c. enhance the absorption of calcium and phosphorus d. participate in blood clotting

a. prevent oxidative damage to cell membranes

Which of the following is considered antioxidants? a. vitamin E and beta-carotene b. vitamin D and vitamin K c. vitamin E and vitamin K d. vitamin A and vitamin D

a. vitamin E and beta-carotene

Vitamins are a. essential nutrients needed in large amounts to prevent disease b. classified as either water-soluble or fat-soluble nutrients c. defined as inorganic nutrients d. easily made by the body from leftover glucose

b. classified as either water-soluble or fat-soluble nutrients

Vitamin D a. is not toxic even if consumed in amounts greater than the RDA b. is made in the skin from 7-dehydrocholesterol and ultraviolet light c. is found in whole milk, but not in skim milk d. has an AI rather than an RDA

b. is made in the skin from 7-dehydrocholesterol and ultraviolet light

Vitamins are most likely to be destroyed by a. cold b. ultraviolet light c. acid pH d. digestion

b. ultraviolet light

An individual who does not produce enough bile will have difficulty absorbing a. thiamin (B1) b. vitamin A c. folate d. pantothenic acid

b. vitamin A

Which of the following statements about vitamins is false? a. although the body is capable of synthesizing some vitamins, they are considered essential nutrients b. they are organic compounds present in foods from both animals and plants c. performed vitamins must be converted to provitamins to be active d. they are micronutrients

c. performed vitamins must be converted to provitamins to be active

Vitamin K is necessary for the synthesis of a. glycogen b. rhodopsin c. prothrombin d. cholecalciferol

c. prothrombin

Which of the following statements about fat-soluble vitamins is true? a. they are stored by the body, and thus are not classified as essential nutrients b. after absorption in the enterocytes, they travel via the portal vein to the liver c. they can accumulate to toxic levels in the body d. they are regularly excreted from the body in feces

c. they can accumulate to toxic levels in the body

On a bottle of multivitamins, the Supplemental Facts panel a. must include the USP Verified mark b. certifies that the supplement is safe c. certifies that the supplement has been tested and approved by the FDA d. must list the ingredients in descending order by weight

d. must list the ingredients in descending order by weight