Vitamins and Nutritional Deficiencies Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which population is at highest risk for vitamin deficiency?

Teenagers

Athletes

Alcoholics (correct)

Pregnant women

What is one of the primary functions of vitamin A?

Maintains healthy bones

Helps in iron absorption

Aids in protein synthesis

Supports normal vision (correct)

What cooking method is recommended to preserve the vitamin content in food?

Boiling for extended periods

Deep frying

Using a microwave for quick cooking (correct)

Baking at high temperatures

Which of the following is an early sign of vitamin A deficiency?

Night blindness Signup and view all the answers

What should you avoid when purchasing produce to maximize vitamin content?

Buying wilted or bruised produce Signup and view all the answers

Which vitamin is found in animal sources as retinol?

Vitamin A Signup and view all the answers

What happens to epithelial cells in the case of vitamin A deficiency?

They produce excessive keratin Signup and view all the answers

Which vitamin is known for having stable properties, making it less vulnerable to destruction during storage?

Niacin Signup and view all the answers

What condition results from the keratinization of certain cells, potentially leading to blindness?

Xerophthalmia Signup and view all the answers

What is a major consequence of excess vitamin A intake?

Liver damage Signup and view all the answers

Which food is NOT a recommended source of vitamin D?

Leafy greens Signup and view all the answers

What condition is commonly associated with vitamin D deficiency in children?

Rickets Signup and view all the answers

Where do people synthesize adequate prohormone D most effectively?

Near the equator Signup and view all the answers

Which of the following statements is true regarding dietary supplements with beta-carotene?

They may be harmful, particularly for smokers. Signup and view all the answers

What is a characteristic of cancerous cells?

They are out of control and can metastasize. Signup and view all the answers

Which of the following is NOT considered a major risk factor for cancer?

Consuming too little fiber Signup and view all the answers

What is a reasonable piece of advice for reducing cancer risk?

Limit alcohol consumption. Signup and view all the answers

Which statement best describes carcinogens?

They are environmental factors that may trigger cancer. Signup and view all the answers

Which food sources are rich in folate?

Chicken liver Signup and view all the answers

What happens to red blood cell precursor cells when there is a folate deficiency?

They enlarge but cannot divide. Signup and view all the answers

What is a potential consequence of folate deficiency in pregnant women?

Neural tube defects in infants Signup and view all the answers

Which vitamin is essential for the metabolism of folate?

Vitamin B-12 Signup and view all the answers

What condition is commonly associated with a deficiency of vitamin B-12?

Pernicious anemia Signup and view all the answers

How is vitamin B-12 absorbed in the body?

Requires intrinsic factor for absorption in the ileum Signup and view all the answers

What can lead to food-cobalamin malabsorption?

Declining gastric acid production Signup and view all the answers

What role does pantothenic acid play in the body?

It is critical for energy metabolism and fatty acid production Signup and view all the answers

What condition is characterized by a deficiency of vitamin C?

Scurvy Signup and view all the answers

What is a primary function of biotin in the human body?

Promotion of glucose and fatty acid synthesis Signup and view all the answers

Which group of individuals may be at higher risk of pantothenic acid deficiency?

People who abuse alcohol Signup and view all the answers

What is one of the major roles of vitamin C in the body?

Strengthening connective tissues Signup and view all the answers

Which of the following is a potential side effect of taking high doses of niacin?

Skin flushing Signup and view all the answers

What is the primary source of biotin in the body?

Intestinal bacteria Signup and view all the answers

What is the minimum daily intake of vitamin C required to prevent scurvy?

10 mg Signup and view all the answers

What is true about choline in humans?

It is considered a vitamin-like nutrient. Signup and view all the answers

Which vitamins are classified as fat-soluble?

A, D, E, K Signup and view all the answers

Which statement accurately describes water-soluble vitamins?

They are excreted in the urine. Signup and view all the answers

What is the purpose of grain enrichment?

To add specific nutrients to refined grains. Signup and view all the answers

Which factor increases vitamin absorption in the body?

Increased body demand during growth Signup and view all the answers

Which health condition is known to interfere with the absorption of fat-soluble vitamins?

Cystic fibrosis Signup and view all the answers

What is a common reason for vitamin deficiencies in the U.S.?

Poor dietary choices Signup and view all the answers

Which vitamins are generally not stored in major amounts within the body?

B vitamins and C Signup and view all the answers

How do fat-soluble vitamins differ from water-soluble vitamins in terms of toxicity?

Fat-soluble vitamins may become toxic when stored excessively. Signup and view all the answers

Study Notes

Vitamins

Vitamins are complex organic compounds
The body does not make enough vitamins to maintain good health
Vitamins occur naturally in common foods
A deficiency disorder occurs when a vitamin is missing from the diet
Vitamins restore good health when the missing substance is supplied

Learning Outcomes

Classify vitamins as fat-soluble or water-soluble
Discuss methods to conserve vitamin content or increase bioavailability
Explain the function of antioxidants and define enrichment/fortification
List the four fat-soluble vitamins and identify dietary sources
Discuss major functions of each fat-soluble vitamin
Identify health problems associated with excesses and deficiencies of fat-soluble vitamins
List water-soluble vitamins and identify dietary sources
Discuss major functions of each water-soluble vitamin
Identify health problems associated with excesses and deficiencies of water-soluble vitamins
Identify health problems from excesses and deficiencies of vitamin B12, vitamin C, pantothenic acid, and biotin
Evaluate vitamin supplements, considering health benefits and hazards
Identify foods that may increase cancer risk
Discuss steps to reduce cancer risk

Vitamins: Basic Concepts

Vitamins are complex organic compounds
The body does not produce enough to maintain good health
Vitamins occur naturally in common foods
A deficiency in vitamins can cause deficiency disorders
Supplementing with missing vitamins can restore good health

Major Roles of Vitamins

Vitamins have hormonal action (e.g., vitamin D)
Vitamins participate in chemical reactions (e.g., anti-oxidation)
Vitamins do not provide energy
Vitamins regulate various bodily processes (e.g., cell division, tissue growth)

Radical Formation and Vitamins

Oxidation reactions form radicals ("free radicals")
Radicals are substances with an unpaired electron and involve the loss of electrons
Free radicals are highly reactive and unstable
Free radicals can remove electrons from more stable molecules (e.g., DNA, proteins, polyunsaturated fatty acids)
Free radical damage contributes to chronic diseases and premature aging
Vitamins (e.g., vitamin E, vitamin C) have anti-oxidation effects

How Do Antioxidants Work?

Antioxidants donate an electron to stabilize a radical
By donating an electron, the radical is stabilized, protecting other molecules

Free Radicals and Antioxidants

Free radicals have an unpaired electron; antioxidants donate an electron to stabilize them.

Sources of Vitamins

Vitamins occur naturally in food, or are synthesized in labs (supplements)
Biological activity refers to the effect of vitamins in the body
Some vitamins are more active in natural form, while others are more active in synthetic form (e.g., folate)
Bacteria in the large intestine produce certain vitamins (biotin and vitamin K), and the body can synthesize vitamin D and niacin under certain conditions.

How are Vitamins Classified?

Fat-soluble vitamins (A, D, E, and K) are associated with lipids in food and the body
Fat-soluble vitamins do not dissolve in water or urine, generally are stored in the body, and can be toxic in excessive amounts
Water-soluble vitamins (C and B-complex, including B1, B2, B3, B6, B7, B9, B12, and Choline) dissolve in watery components of food and the body.
Water-soluble vitamins are usually not stored in significant amounts and are generally non-toxic

Vitamin Enrichment and Fortification

Raw foods can lose nutrients during processing (like refinement)
Grain enrichment adds thiamin, riboflavin, niacin, folic acid, and mineral iron to refined grains to restore nutrients lost during processing
Fortification adds any nutrient to a wide array of commonly eaten processed foods during manufacturing

Vitamin Absorption

Most vitamins are absorbed in the small intestine.
Absorption increases when the body requires more of the vitamin
Fat-soluble vitamins are absorbed along with dietary fat.
Diseases affecting the GI tract can reduce vitamin absorption (e.g., cystic fibrosis)

Vitamin Deficiency and Toxicity Disorders

Deficiencies can result from poor diets or certain health conditions.
In the U.S., severe deficiencies are uncommon due to food preservation, enrichment, and fortification, plus widespread fruit and vegetable availability
Some Americans don't consume sufficient amounts of vitamin E, D, and choline

Populations at Risk for Vitamin Deficiency

Alcoholics
Older adults
Hospitalized people
People with anorexia nervosa
People with certain gastrointestinal disorders
People with rare metabolic conditions

Maximizing Vitamin Contents of Food

Vitamin C, thiamine, and folate are easily destroyed by poor storage and preparation practices
Niacin and vitamin D tend to be very stable
Tips for preserving vitamin content: avoid wilted, bruised, or shriveled produce; cook in small amounts of water; avoid large pieces of food; use quick cooking methods (e.g., microwaving, steaming, stir-frying); freeze produce

Vitamin A

Animal sources: retinol (most active form) – liver, fish liver oils
Plant sources: beta-carotene (provitamin A) – yellow-orange and green fruits and vegetables
Major functions: normal vision, reproduction, cellular growth, immune system activity, and epithelial cell production
See page 20 on the presentation for a table of vitamin A in various foods

Vitamin D

Major functions: increasing calcium and phosphate deposits in bone, reducing urinary calcium excretion, and increasing calcium and phosphate absorption
Synthesis occurs in skin when exposed to ultraviolet light
See presentation pages 25-29 for major sources

Vitamin E

Major functions: antioxidant activity, maintenance of the nervous and immune system
See pages 33-35 for major sources

Vitamin K

Major Functions: produces active blood-clotting factors
See pages 36-38 for major sources

Water-Soluble Vitamins

Many function as components of specific coenzymes (small molecules that help enzymes function)
Enzymes require coenzymes to function. Coenzymes regulate chemical reactions by interacting with enzymes. Once activated, the coenzyme-enzyme complex enables the reaction to occur
See pages 39-40 for major sources

Thiamin (B1)

Part of coenzyme involved in energy release from carbohydrates.
Involves metabolism of certain amino acids.
Synthesis of neurotransmitters
Deficiency Disease: Beriberi; Wernicke-Korsakoff syndrome (alcoholics)
See Page 41 for food sources

Riboflavin (B2)

Coenzyme for metabolism of carbohydrates, lipids, and amino acids.
Dairy foods, liver, enriched grains are significant food sources
See Page 43 for food sources

Niacin (B3)

Part of two coenzymes necessary to obtain energy from macronutrients
Deficiency can result in dermatitis, diarrhea, dementia, and death ("4 D's" of pellagra)
High doses (megadoses) can cause GI ulcers, vision problems, and liver damage
See Page 44 for food sources

Vitamin B6

Part of coenzyme needed for amino acid metabolism
Deficiency rarely occurs but can lead to dermatitis, anemia, convulsions, depression, and confusion
High doses (megadoses) can cause nerve damage
See Page 46 for food sources

Folate

Part of the coenzyme tetrahydrofolic acid (THFA) required for DNA and amino acid metabolism.
Converts homocysteine into methionine, and plays a major role in vitamin B12 function
Leafy greens, liver, legumes, asparagus, and oranges are significant food sources
See pages 47-49 for details

Vitamin B12

Part of coenzymes needed for folate metabolism and myelin sheath maintenance.
Binds to intrinsic factor for absorption in the ileum
Food-cobalamin (B12) malabsorption is common in older adults due to declining gastric acid production.
See pages 56-57 for details

Pantothenic Acid and Biotin

Pantothenic acid (B5) is a component of coenzyme A, critical for energy metabolism and fatty acid production. Pantothenic acid is widely available in foods
Biotin (B7) participates in chemical reactions adding carbon dioxide to other compounds, promoting the synthesis of glucose and fatty acids and breaking down amino acids.
Intestinal bacteria produce biotin, preventing biotin deficiencies

Vitamin C

Not part of a coenzyme, but needed for collagen synthesis, antioxidant activity, immune system function, and the synthesis of bile and some neurotransmitters and hormones
Deficiency results in scurvy
See pages 55-57 for details

Choline

Humans need choline, especially during prenatal development
Choline is a vitamin-like nutrient
The body can produce choline but may not produce enough in certain conditions
See page 58 for details

Vitamin as Medicine

Niacin (B3): can lower LDL cholesterol and raise HDL cholesterol, but high doses are toxic.
Vitamin B6: some research suggests it may help with PMS, but high doses can cause nerve damage
Folic Acid, B6, B12: lower blood homocysteine levels when taken together; research on CVD reduction and Alzheimer's disease prevention is mixed/inconclusive
Vitamin C: does no prevent colds, but may reduce duration and severity; has antioxidant activity
Vitamin E: questionable benefits for reducing chronic disease/cancer risks and may increase cancer risk
Carotenoids (as supplements): may help reduce AMD progression but possibly harmful, especially for smokers

Cancer

Group of chronic diseases; characterized by cells with mutated (damaged) genes
Cancerous (malignant) cells are out of control; can spread (metastasize)
Carcinogens are environmental factors that trigger cancer; examples can be age, tobacco use, radiation exposure, certain bacteria/viral infections, certain hormone levels, alcohol, certain specific foods, and other environmental exposure)
See pages 65-67 for details

Reducing Cancer Risk

Limit alcohol
Maintain a healthy weight
Adopt physically active lifestyle
Eat a healthy diet, emphasizing plant foods, and limiting red and processed meats
Avoid environmental exposures to carcinogens

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on essential vitamins, their functions, and the risks of deficiencies. This quiz covers the importance of vitamins A and D, the consequences of their lack, and ways to maintain vitamin content in foods. Challenge yourself to see how well you understand these crucial nutrients.