Topic 6&7

Question 1

[cite_start]”Vitamin Definition”

Answer 1

Essential organic substance from food, needed in small amounts for body metabolism and function. Both deficiencies and excesses can affect health. [cite: 1452, 1455]

Question 2

[cite_start]”Bioavailability (Definition)”

Answer 2

The rate and extent that a nutrient is absorbed and utilized by the body. [cite: 1457]

Question 3

[cite_start]”Factors Influencing Bioavailability”

Answer 3

Efficiency of digestion, previous nutrient intake/status, method of food preparation, source of nutrient, and other foods consumed at the same time. [cite: 1462, 1464, 1465, 1466, 1467]

Question 4

[cite_start]”Precursors (Pro-vitamins)”

Answer 4

Compounds consumed in an inactive form and converted into active vitamins within the body. [cite: 1469, 1470]

Question 5

[cite_start]”Vitamin Destruction (Organic Nature)”

Answer 5

Vitamins can be destroyed by exposure to light, oxidation, cooking, and storage. [cite: 1475]

Question 6

[cite_start]”Methods to Minimize Vitamin Loss (Examples)”

Answer 6

Refrigerate fruits/vegetables , store cut foods in airtight containers , use microwave, steam, or simmer in small amounts of water , avoid high temperatures and long cooking times.

Question 7

[cite_start]”Water-Soluble Vitamins (List)”

Answer 7

B Vitamins (Thiamin $B_{1}$, Riboflavin $B_{2}$, Niacin $B_{3}$, Pyridoxine $B_{6}$, Folate $B_{9}$, Cobalamin $B_{12}$, Pantothenic acid $B_{5}$, Biotin $B_{7}$) and Vitamin C. [cite: 1495]

Question 8

[cite_start]”Water-Soluble Vitamins: Absorption”

Answer 8

Absorbed directly into the blood. [cite: 1495]

Question 9

[cite_start]”Water-Soluble Vitamins: Transport”

Answer 9

Travel freely in the water-filled parts of the body. [cite: 1495]

Question 10

[cite_start]”Water-Soluble Vitamins: Storage”

Answer 10

Circulate freely; minimal storage. [cite: 1495]

Question 11

[cite_start]”Water-Soluble Vitamins: Excretion”

Answer 11

Kidneys detect and remove excess in urine. [cite: 1495]

Question 12

[cite_start]”Water-Soluble Vitamins: Toxicity”

Answer 12

Possible to reach toxic levels when consumed from supplements. [cite: 1495]

Question 13

[cite_start]”Water-Soluble Vitamins: Requirements”

Answer 13

Needed in frequent doses (perhaps 1-3 days). [cite: 1495]

Question 14

[cite_start]”Primary Role of B Vitamins”

Answer 14

Act primarily as coenzymes [cite: 1498][cite_start], functioning as catalysts in energy-producing metabolic reactions. [cite: 1500]

Question 15

[cite_start]”Thiamin ($B_{1}$) Role”

Answer 15

Releases energy from carbohydrates; part of coenzyme Thiamin Pyrophosphate (TPP), involved in converting pyruvate to acetyl CoA and CAC cycle. [cite: 1537, 1538, 1539, 1540]

Question 16

[cite_start]”Thiamin ($B_{1}$) Deficiency Disease”

Answer 16

Beri-beri. [cite: 1548]

Question 17

[cite_start]”Beri-beri Symptoms (Wet vs Dry)”

Answer 17

Loss of appetite, irritability, fatigue, and constipation[cite: 1548]. Wet beriberi presents with edema; [cite_start]Dry beriberi presents with muscle wasting. [cite: 1549, 1550]

Question 18

[cite_start]”Riboflavin ($B_{2}$) Coenzyme Forms”

Answer 18

Flavin Mononucleotide (FMN) and Flavin Adenine Dinucleotide (FAD); both serve as coenzymes in energy metabolism.

Question 19

[cite_start]”Riboflavin ($B_{2}$) Destruction”

Answer 19

Easily destroyed by ultraviolet light and irradiation, but not destroyed by cooking. [cite: 1637, 1638]

Question 20

[cite_start]”Riboflavin ($B_{2}$) Deficiency Disease”

Answer 20

Ariboflavinosis. [cite: 1646]

Question 21

[cite_start]”Ariboflavinosis Symptoms”

Answer 21

Inflamed eyelids, light sensitivity, reddening of the cornea, sore throat, cracks/redness at mouth corners (cheilosis), and painful, smooth purplish-red tongue (glossitis). [cite: 1644, 1645]

Question 22

[cite_start]”Niacin ($B_{3}$) Precursor”

Answer 22

The amino acid tryptophan (60 mg Tryptophan = 1 mg Niacin). [cite: 1735, 1740]

Question 23

[cite_start]”Niacin ($B_{3}$) Coenzyme Forms”

Answer 23

Nicotinamide Adenine Dinucleotide (NAD) and NADP (the phosphate form); involved in metabolism of glucose, fat, and alcohol. [cite: 1726, 1727]

Question 24

[cite_start]”Niacin ($B_{3}$) Deficiency Disease”

Answer 24

Pellagra. [cite: 1728]

Question 25

[cite_start]"Pellagra Symptoms (The 4 Ds)"

Answer 25

Diarrhea, abdominal pain/vomiting[cite: 1730]; [cite_start]Dermatitis (rash when exposed to sunlight)[cite: 1732]; [cite_start]Dementia (loss of memory, depression, apathy)[cite: 1732]; and Death.

Question 26

[cite_start]"Niacin ($B_{3}$) Toxicity Symptoms"

Answer 26

Painful flush, hives/rash, excessive sweating, blurred vision, **liver damage**, and impaired glucose tolerance. [cite: 1747, 1750, 1751]

Question 27

[cite_start]"Biotin ($B_{7}$) Role"

Answer 27

Coenzyme that carries activated carbon dioxide; critical in the **TCA cycle** to form oxaloacetate; participates in gluconeogenesis and fatty acid synthesis. [cite: 1835, 1836, 1837]

Question 28

[cite_start]"Biotin ($B_{7}$) Sources"

Answer 28

Found in various foods (e.g., egg yolks); also **produced by GI bacteria**. [cite: 1842]

Question 29

[cite_start]"Pantothenic Acid ($B_{5}$) Role"

Answer 29

Part of **Coenzyme A (CoA)** in energy metabolism. [cite: 1846]

Question 30

[cite_start]"Pantothenic Acid ($B_{5}$) Stability"

Answer 30

Easily destroyed by **food processing**. [cite: 1850]

Question 31

[cite_start]"Pyridoxine ($B_{6}$) Coenzyme Forms"

Answer 31

**Pyridoxal Phosphate (PLP)** and Pyridoxamine Phosphate (PMP); used in **amino and fatty acid metabolism**. [cite: 1856]

Question 32

[cite_start]"Pyridoxine ($B_{6}$) Other Roles"

Answer 32

Helps convert tryptophan to niacin or serotonin, and helps make **red blood cells**. [cite: 1857, 1858]

Question 33

[cite_start]"Pyridoxine ($B_{6}$) Toxicity"

Answer 33

Can cause **irreversible nerve damage** in high doses. [cite: 1860]

Question 34

[cite_start]"Folate ($B_{9}$) Role (DNA/Cells)"

Answer 34

Part of coenzymes **THF** and **DHF** used in **DNA synthesis** and therefore important for new cell formation and normal **red blood cell synthesis**. [cite: 1868, 1869]

Question 35

[cite_start]"Folate ($B_{9}$) Role (Fetus)"

Answer 35

Important for the development of the **fetus during the first trimester**. [cite: 1870]

Question 36

[cite_start]"Folate and $B_{12}$ Relationship"

Answer 36

Folate coenzymes (THF and DHF) require **vitamin $B_{12}$ to function correctly**. [cite: 1871]

Question 37

[cite_start]"Folate ($B_{9}$) Recommended Intake (Women)"

Answer 37

Women of childbearing age need **400 micrograms/day of folic acid**. [cite: 1876]

Question 38

[cite_start]"Cobalamin ($B_{12}$) Role"

Answer 38

Helps maintain nerve cells, reforms folate coenzyme, and helps break down some fatty/amino acids. [cite: 1955, 1956, 1957]

Question 39

[cite_start]"Cobalamin ($B_{12}$) Absorption"

Answer 39

Binds with **intrinsic factor** in the small intestine for absorption. [cite: 1958]

Question 40

[cite_start]"Cobalamin ($B_{12}$) Sources"

Answer 40

Almost only found in **meat, fish, milk/milk-based products, and eggs** (animal products). [cite: 1960]

Question 41

[cite_start]"Vitamin C Coenzyme Role"

Answer 41

**Cofactor** in **collagen formation** (used for bones, teeth, scar tissue, artery walls) [cite: 2072, 2073][cite_start], and cofactors in hydroxylation of carnitine, converting tryptophan to neurotransmitters, and making hormones. [cite: 2076, 2077, 2078]

Question 42

[cite_start]"Vitamin C Antioxidant Role"

Answer 42

**Antioxidant**[cite: 2069]. [cite_start]Defends against **free radicals** and protects tissues from oxidative stress by donating its two hydrogens to free radicals. [cite: 2070, 2071, 2051]

Question 43

Active Forms of Vitamin C

Answer 43

**Ascorbic acid** (reduced form) and **dehydroascorbic acid** (oxidized form). [cite_start]The reversibility is key to its antioxidant role. [cite: 2039, 2054]

Question 44

[cite_start]"Vitamin C Deficiency Disease"

Answer 44

**Scurvy**. [cite: 2124]

Question 45

[cite_start]"Scurvy Symptoms (Key Features)"

Answer 45

Gums become scorbutic (symmetrical appearance without infection) , pinpoint hemorrhages (spontaneous bleeding) wounds don't heal/reopen , long bones soften/fractures occur , and internal hemorrhaging/sudden death can result.

Question 46

[cite_start]"Factors Increasing Vitamin C Need"

Answer 46

Infections, burns, temperature extremes, heavy metal intakes, certain medications, and **smoking**. [cite: 2081]

Question 47

[cite_start]"Vitamin C Toxicity Concerns"

Answer 47

At high doses, may act as an **oxidant** rather than an antioxidant. May encourage kidney stones in people with kidney disease. High doses followed by abrupt stop can cause 'reactive scurvy'.

Question 48

Choline (Vitamin-like)

Answer 48

Made from methionine. [cite_start]Needed for synthesis of neurotransmitter **acetylcholine** and phospholipid **lecithin**. [cite: 2210, 2211]

Question 49

Carnitine (Vitamin-like)

Answer 49

Made from lysine. [cite_start]**Transports long-chain fatty acids** for oxidation across the mitochondrial membrane. [cite: 2216, 2217]

Question 50

[cite_start]"Inositol (Vitamin-like)"

Answer 50

Made from glucose; part of the **cell membrane structure**. [cite: 2221]

Question 51

Taurine (Vitamin-like)

Answer 51

Synthesis from cysteine. [cite_start]Involved in **bile salt formation**, membrane stabilization, and neurodevelopment. [cite: 2223, 2224]

Question 52

[cite_start]"Lipoic Acid (Vitamin-like)"

Answer 52

Cofactor in energy metabolism and an **antioxidant**. [cite: 2228, 2229]

Question 53

[cite_start]"Bogus Vitamins (Examples)"

Answer 53

Substances once thought to be vitamins but lacked a proven essential role, e.g., Laetrile ($B_{17}$), pangamic acid ($B_{15}$), orotic acid. [cite: 2231, 2232]

Question 54

[cite_start]"Argument For Supplements: Deficiency/Needs"

Answer 54

Correct overt deficiencies [cite: 2243][cite_start]; support increased nutrient needs during certain life stages (e.g., pregnancy, growth, elderly) or restricted diets. [cite: 2247, 2250]

Question 55

[cite_start]"Argument For Supplements: Disease/Defense"

Answer 55

Adequate intake of antioxidant vitamins/minerals may support immune function [cite: 2257][cite_start]; evidence supports Folic acid (pregnancy) and Vitamin D + Calcium (bone health). [cite: 2259, 2260]

Question 56

[cite_start]"Who Needs $B_{12}$ Supplementation"

Answer 56

Vegans and those with atrophic gastritis (impaired absorption). [cite: 2267]

Question 57

[cite_start]"Who Needs Folate/Iron Supplementation"

Answer 57

Pregnant women[cite: 2274]; [cite_start]Women of childbearing age need folate. [cite: 2273]

Question 58

[cite_start]"Argument Against Supplements: Toxicity"

Answer 58

Excessive intake, especially of fat-soluble vitamins and minerals, can cause toxic effects. [cite: 2280]

Question 59

[cite_start]"Argument Against Supplements: Misinformation"

Answer 59

Relying on supplements instead of proper medical treatment for serious illnesses. [cite: 2282]

Question 60

[cite_start]"Argument Against Supplements: False Security"

Answer 60

May lead people to neglect healthy habits (balanced diet, exercise) because they feel protected. [cite: 2291]

Question 61

[cite_start]"Fat-Soluble Vitamin Characteristics"

Answer 61

Require **bile** for digestion and absorption [cite: 1660][cite_start]; travel through the **lymphatic system** [cite: 1661][cite_start]; many require transport proteins in the bloodstream [cite: 1662][cite_start]; excesses are **stored**[cite: 1662].

Question 62

[cite_start]"Vitamin A (Forms in the Body)"

Answer 62

Compounds known as **retinoids**: retinol, retinal, and retinoic acid[cite: 1665].

Question 63

[cite_start]"Vitamin A Precursors"

Answer 63

**Carotenoids** (e.g., beta-carotene)[cite: 1668].

Question 64

[cite_start]"Vitamin A Key Roles"

Answer 64

Vision [cite: 1666][cite_start], healthy epithelial cells [cite: 1666][cite_start], and growth[cite: 1666].

Question 65

[cite_start]"Vitamin A Absorption/Transport"

Answer 65

Absorbed vitamin A is incorporated into **chylomicrons** and transported via the lymphatic system to the liver[cite: 1675]. [cite_start]Requires **Retinol Binding Protein (RBP)** for transport out of the liver[cite: 1677, 1678].

Question 66

[cite_start]"Vitamin A Storage"

Answer 66

The **liver** stores about 50-80% of the body's vitamin A, mainly as retinyl esters[cite: 1676].

Question 67

[cite_start]"Vitamin A Conversion Reversibility"

Answer 67

Conversion of **retinol to retinal is reversible** [cite: 1711][cite_start]; conversion of **retinal to retinoic acid is irreversible**[cite: 1711].

Question 68

[cite_start]"Vitamin A Role in Vision (Mechanism)"

Answer 68

Helps maintain the **cornea**[cite: 1716]. [cite_start]Is part of **Rhodopsin** (a light-sensitive pigment containing the protein opsin) in the retina [cite: 1717, 1723][cite_start], which changes shape upon light absorption, triggering a nerve impulse[cite: 1730].

Question 69

[cite_start]"Vitamin A Role in Cell Differentiation"

Answer 69

**Retinoic acid** regulates gene expression and promotes cell differentiation, allowing cells to develop specialized functions[cite: 1697, 1738].

Question 70

[cite_start]"Vitamin A Role in Bone Remodeling"

Answer 70

Supports bone growth and reshaping by regulating **osteoclast** (destroy bone) and **osteoblast** (build bone) activity[cite: 1757, 1759, 1760, 1761].

Question 71

[cite_start]"First Detectable Sign of Vitamin A Deficiency"

Answer 71

**Night Blindness**[cite: 1769]. [cite_start]Caused by impaired regeneration of rhodopsin in the retina[cite: 1771].

Question 72

[cite_start]"Blindness due to Vitamin A Deficiency"

Answer 72

**Xerophthalmia**[cite: 1784]. [cite_start]Stages include **Xerosis** (dry, hard cornea) [cite: 1786] [cite_start]and **Keratomalacia** (softening of the cornea)[cite: 1787].

Question 73

[cite_start]"Keratinization (Deficiency Symptom)"

Answer 73

Changes in epithelial cells resulting in rough, dry, scaly skin and improper protein secretion (keratin, the hard protein of hair/nails)[cite: 1788, 1789, 1790].

Question 74

[cite_start]"Irreversible Blindness Cause"

Answer 74

Severe, prolonged Vitamin A deficiency (Xerophthalmia)[cite: 1784].

Question 75

[cite_start]"Vitamin A Toxicity Disease"

Answer 75

**Hypervitaminosis A**[cite: 1810, 1812].

Question 76

[cite_start]"Vitamin A Toxicity Symptoms (Chronic/Acute)"

Answer 76

Chronic: **Liver abnormalities**[cite: 1814]. [cite_start]Acute: blurred vision, nausea, vomiting, vertigo, headaches, and pressure in the skull[cite: 1815].

Question 77

[cite_start]"Vitamin A Toxicity and Bone"

Answer 77

Excess Vitamin A stimulates **osteoclast** activity, leading to increased bone resorption, weakened bones, and higher risk of osteoporosis/fractures[cite: 1798, 1799].

Question 78

[cite_start]"Vitamin A Toxicity and Pregnancy"

Answer 78

**Teratogenic risk** (abnormal fetal development/birth defects)[cite: 1802]. [cite_start]Supplements and retinoid acne meds are not recommended during the first trimester[cite: 1803, 1804].

Question 79

[cite_start]"Beta-Carotene Toxicity"

Answer 79

Not toxic, but high intakes may cause harmless **carotenemia** (skin discoloration)[cite: 1670, 1805].

Question 80

[cite_start]"Vitamin A Food Sources (Retinol)"

Answer 80

Fortified milk, cheese, cream, butter, fortified margarine, eggs, and liver[cite: 1825, 1831].

Question 81

[cite_start]"Vitamin A Food Sources (Beta-Carotene)"

Answer 81

Spinach and other **dark green leafy vegetables**, deep orange fruits (apricots), deep orange vegetables (squash, carrots, sweet potatoes, pumpkin)[cite: 1826, 1827, 1828, 1829].

Question 82

[cite_start]"Vitamin D (Non-food Source)"

Answer 82

Non-essential nutrient that acts like a hormone[cite: 1905]. [cite_start]Synthesized in the body from **cholesterol** [cite: 1985] [cite_start]with adequate exposure to **sunlight**[cite: 1906].

Question 83

[cite_start]"Vitamin D Forms"

Answer 83

**Ergocalciferol (Vitamin $D_{2}$)** from plants[cite: 1909]; [cite_start]**Cholecalciferol (Vitamin $D_{3}$)** from animals or skin synthesis[cite: 1911].

Question 84

Vitamin D Activation Steps

Answer 84

1. [cite_start]In the **liver**, $D_{3}$ is hydroxylated to 25-hydroxy vitamin $D_{3}$[cite: 1921, 1924]. 2. [cite_start]In the **kidneys**, a second hydroxylation forms **1,25-dihydroxy vitamin D ($D_{3}$)** (**Calcitriol**), the active form[cite: 1913, 1927]." [cite_start]"Vitamin D Role in Bone Growth

Question 85

[cite_start]"Vitamin D Deficiency in Children"

Answer 85

**Rickets**[cite: 1948]. [cite_start]Characterized by soft, weak, and **deformed bones** (e.g., bowed legs, beaded ribs)[cite: 1949, 1963, 1964].

Question 86

[cite_start]"Vitamin D Deficiency in Adults"

Answer 86

**Osteomalacia/Osteoporosis**[cite: 1950]. [cite_start]Leads to calcium loss from bones, reduced bone density, and soft, brittle bones[cite: 1952, 1953].

Question 87

[cite_start]"Factors Contributing to Vitamin D Deficiency"

Answer 87

Dark skin, limited sunlight exposure[cite: 1946, 1947]. [cite_start]In the elderly: reduced skin synthesis/activation, low milk consumption, limited sun exposure[cite: 1956, 1957, 1958].

Question 88

[cite_start]"Vitamin D Toxicity Disease"

Answer 88

**Hypervitaminosis D**[cite: 1971]. [cite_start]High-dose supplements are the likely cause[cite: 1969].

Question 89

[cite_start]"Vitamin D Toxicity Symptom"

Answer 89

**Hypercalcemia** (elevated blood calcium) [cite: 1970, 1973][cite_start], leading to **calcification of soft tissues** (blood vessels, kidneys, heart, lungs)[cite: 1974].

Question 90

[cite_start]"Vitamin D Food Sources"

Answer 90

Fortified milk, butter, margarine, cereals, chocolate mixes, beef, egg yolks, liver, and **fatty fish and their oils**[cite: 1979, 1982].

Question 91

[cite_start]"Vitamin E Biologically Active Form"

Answer 91

**Alpha-tocopherol**[cite: 1992]. [cite_start]Exists in four tocopherol compounds ($\alpha, \beta, \gamma, \delta$)[cite: 1990].

Question 92

[cite_start]"Vitamin E Role"

Answer 92

Acts as a major **lipid-soluble antioxidant**[cite: 1997]. [cite_start]Stops **free radical chain reactions**, protecting **PUFAs** and vitamin A from oxidation[cite: 1998, 1999].

Question 93

[cite_start]"Vitamin E Deficiency Symptom"

Answer 93

**Erythrocyte hemolysis** (breakdown of red blood cells), resulting in **hemolytic anemia** (occurs in premature infants)[cite: 2002, 2004].

Question 94

[cite_start]"Vitamin E Toxicity Concern"

Answer 94

Extremely high doses may **interfere with the blood clotting action of Vitamin K**[cite: 2007].

Question 95

[cite_start]"Vitamin E Food Sources"

Answer 95

**Polyunsaturated plant oils** (margarine, salad dressings), leafy green vegetables, wheat germ, whole grains, nuts, and seeds[cite: 2012, 2013, 2014, 2015, 2017].

Question 96

[cite_start]"Vitamin K Synthesis"

Answer 96

Unique in that **half of human needs are met through the action of intestinal bacteria**[cite: 2027].

Question 97

[cite_start]"Vitamin K Primary Role"

Answer 97

Essential in **blood clotting**[cite: 2028]. [cite_start]Required for the synthesis of **blood-clotting proteins** (e.g., prothrombin)[cite: 2033]." [cite_start]"Vitamin K Other Role

Question 98

[cite_start]"Vitamin K Deficiency Symptom"

Answer 98

**Uncontrolled bleeding** or **hemorrhaging**[cite: 2029, 2034, 2058].

Question 99

[cite_start]"Vitamin K Deficiency at Birth"

Answer 99

Newborn infants receive a single dose of vitamin K at birth because of a **sterile intestinal tract**[cite: 2030, 2060]." [cite_start]"Vitamin K Toxicity Concern

Question 100

[cite_start]"Vitamin K Food Sources"

Answer 100

Bacterial synthesis in the digestive tract [cite: 2050][cite_start], **liver** [cite: 2052][cite_start], **leafy green vegetables and cabbage-type vegetables** [cite: 2053][cite_start], and milk[cite: 2054].