1. The Vitamins: A Functional Approach
Chapter 7
The Vitamins:
A Functional Approach

2. Ask Yourself True or False?
The most important role that vitamins play is providing energy.
You can’t overdose on vitamins, because the body excretes them in the urine.
Serving for serving, fruits and vegetables tend to be the richest sources of vitamins.
Vitamin D is also known as the “sunshine vitamin” because the body can make vitamin D with the help of sunlight.
Vitamin C supplements prevent colds.

3. Ask Yourself
Several major public health associations recommend that all adults take antioxidant supplements.
Fresh vegetables contain more vitamins than frozen vegetables.
Phytochemicals are beneficial nonnutrient substances found in fruits, vegetables, and whole grains.
In general, nutrients are absorbed equally as well from foods as from supplements.
Maintaining a healthy weight may be one of the most important ways to protect against cancer.

4. Turning Back the Clock
Many vitamin deficiency diseases have been eliminated today with the discovery of vitamins.
Scurvy
The vitamin C deficiency disease characterized by bleeding gums, tooth loss, and even death in severe cases.
Rickets
A disease that occurs in children as a result of vitamin D deficiency and that is characterized by abnormal growth of bone, which in turn leads to bowed legs and an outward-bowed chest.
Pellagra
Niacin deficiency characterized by diarrhea, inflammation of the skin, and, in severe cases, mental disorders and death.

5. The Vitamins
Vitamin:
A potent, indispensable compound that performs various bodily functions that promote growth and reproduction and maintain health.
Vitamins are organic, meaning that they contain or are related to carbon compounds.
Contrary to popular belief, vitamins do not supply calories.
They are essential to helping the body make use of the calories consumed via foods.

10. Two Classifications of Vitamins

11. Water-Soluble Vitamins
Water-soluble vitamins act as coenzymes.
Coenzymes
Enzyme helpers; small molecules that interact with enzymes and enable them to do their work.
Water-soluble vitamins are fragile:
Can be washed out or destroyed during food storage, processing and preparation.

12. With the coenzyme in place, A and B are attracted to the AB B B
Enzyme
Enzyme
Without the coenzyme,
compounds A and B
don’t respond to the
enzyme.
With the coenzyme in place,
A and B are attracted to the
active side on the enzyme,
and they react.
The reaction is completed.
A new product, AB, has
Been formed.
Figure 7.2: How a Coenzyme Works.

13. Fat-Soluble Vitamins
ADEK
Absorbed from the digestive tract with the aid of fats in the diet and bile produced by the liver.
Transported by protein carriers in the bloodstream.
Stored in the liver and body fat:
Do not need to consume daily.

14. Antioxidant Vitamins:
Enhance the immune system
Limit free-radical formation
Destroy free radicals and prevent oxidative damage to cells
Reduce inflammation in blood vessel walls
Vitamin C defends body cells and tissues such as skin, lungs, and blood.
Vitamin E and beta-carotene defend the body’s lipids such as cell membranes and lipoproteins.

15. The Antioxidant Vitamins
Some chemical reactions in the body involve the use of oxygen.
These reactions create toxic compounds called free radicals.
These free radicals contribute to cell damage and the development of chronic diseases such as cancer and heart disease.

17. Chronic disease (heart disease, membrane lipids and proteins
cancer) and aging
Damage cell
membrane lipids and proteins
Sunlight
Damage protein
enzymes
Cigarettes
Free
Radicals
Alter cellular DNA
Figure 7.3: The Antioxidants Versus Free Radicals in the Body.
A. Free radicals—unstable oxygen molecules—can be formed from sunlight, in cigarette smoke and environmental pollution, and as a result of many normal chemical reactions involving oxygen in the body. These free radicals attack healthy molecules in the body in hopes of stealing an electron to help stabilize themselves, which in turn can cause cell and tissue damage to the body. Free radical activity can cause damage to the body’s enzymes, cell membranes, and nuclear DNA, or they can result in the formation of oxidized LDL-cholesterol in the arteries. B. The antioxidant team includes vitamin C, vitamin E, the carotenoids (for example, beta-carotene, lutein, zeaxanthin, lycopene), selenium (a trace mineral), and many naturally occurring nonnutrients—called phytochemicals—found in fruits, vegetables, legumes, and whole grains. The antioxidants prevent free radicals from attacking cells and causing damage by neutralizing the free radicals and converting them back into stable oxygen molecules.
SOURCE: Adapted from Antioxidant Nutrients (Mount Olive, NJ: BASF Corporation, 1997).
Oxidize
blood cholesterol
Environmental
pollution
Body
processes

18. The Antioxidant Team Free Radicals Neutralize free radicals
Figure 7.3: The Antioxidants Versus Free Radicals in the Body.
A. Free radicals—unstable oxygen molecules—can be formed from sunlight, in cigarette smoke and environmental pollution, and as a result of many normal chemical reactions involving oxygen in the body. These free radicals attack healthy molecules in the body in hopes of stealing an electron to help stabilize themselves, which in turn can cause cell and tissue damage to the body. Free radical activity can cause damage to the body’s enzymes, cell membranes, and nuclear DNA, or they can result in the formation of oxidized LDL-cholesterol in the arteries. B. The antioxidant team includes vitamin C, vitamin E, the carotenoids (for example, beta-carotene, lutein, zeaxanthin, lycopene), selenium (a trace mineral), and many naturally occurring nonnutrients—called phytochemicals—found in fruits, vegetables, legumes, and whole grains. The antioxidants prevent free radicals from attacking cells and causing damage by neutralizing the free radicals and converting them back into stable oxygen molecules.
SOURCE: Adapted from Antioxidant Nutrients (Mount Olive, NJ: BASF Corporation, 1997).
Neutralize free
radicals

19. The Antioxidant Vitamins
Antioxidant nutrients are the body’s defense against free radical damage.
Antioxidant nutrients include:
Vitamin C
Vitamin E
The carotenoids—beta-carotene
Selenium - found in an enzyme that helps to fight free radicals (Chapter 8)

20. The Antioxidant Vitamins
Vitamin C:
Blocks free radical formation and along with vitamin E may reduce heart disease and cancer.
Is a powerful scavenger of air pollutants.
Required for the production and maintenance of collagen.
Boosts the body’s ability to fight infections.

21. The Antioxidant Vitamins
Vitamin C
Potential role as a chronic-disease fighter stems from its workings as an antioxidant.
Antioxidant: a substance, such as a vitamin, that is “anti-oxygen” – that is, it helps to prevent damage done to the body as a result of chemical reactions that involve oxygen.
It’s role in preventing the common cold is insignificant.
Widespread in the food supply but deficiencies do occur.

22. The Antioxidant Vitamins
Sources of Vitamin C
Vitamin C is widespread in the food supply.
Deficiencies arise both in infants not given a source of vitamin C and in children and the elderly.

23. The Antioxidant Vitamins
Vitamin E
Known as a vitamin in search of a disease.
Widespread in the food supply, and deficiencies of the nutrient are rare.
Performs a key role as an antioxidant in the body.
May protect membranes of the lungs, heart, brain, and other organs against pollutants and other environmental hazards.

24. The Antioxidant Vitamins
Vitamin E
People who run the risk of deficiency:
Premature infants who are born before vitamin E is transferred to them from their mothers.
Those who cannot absorb fats as a result of diseases.
Those with certain blood disorders.

25. The Antioxidant Vitamins

26. The Antioxidant Vitamins
The Vitamin A Precursor: Beta Carotene
Beta-carotene is a member of the carotenoid family.
The carotenoids possess antioxidant properties.
May help prevent age-related macular degeneration and lower risk of cataracts.
Beta-carotene: an orange pigment found in plants that is converted into vitamin A inside the body.

27. The Antioxidant Vitamins
Vitamin A
One of the most versatile vitamins; plays roles in several important body processes.
Best known function is in vision.
Night blindness accompanies deficiency
Helps to maintain healthy epithelial tissue.
Up to a year’s supply can be stored in the body, 90% of it in the liver.

28. The Antioxidant Vitamins
Deficiency symptoms appear after your stores are depleted.
Consequences include blindness and reduced resistance to infection.
Toxicity can pose a hazard for those taking preformed vitamin A (supplements).
There is no toxicity risk for beta-carotene.

30. The Antioxidant Vitamins
Sources of Vitamin A and Beta-Carotene
The major sources of vitamin A are almost all brightly colored hues of green, yellow, orange and red.
Vitamin A is measured in Retinol Activity Equivalents (RAE). This is a measure of both preformed vitamin A and beta-carotene in foods.

31. Vitamins for Healthy Blood
The body needs a continuous supply of water, oxygen, energy, and building materials.
Blood carries oxygen and nutrients to cells.
Blood carries away carbon dioxide and waste products.

32. Vitamins for Healthy Blood
Folate is needed for formation and maintenance of healthy red blood cells.
Vitamin B12 is needed for formation of healthy red blood cells.
Vitamin B6 is needed for synthesis of hemoglobin, which carries oxygen in the blood.
Vitamin K is needed for blood clotting.

33. Vitamins for Healthy Blood
Folate
Folic acid or folacin
Coenzyme with many functions in the body.
Important in the synthesis of DNA and the formation of red blood cells.
A deficiency makes the red blood cells misshapen and unable to carry sufficient oxygen...
Causing a certain kind of anemia.
Anemia: any condition in which the blood is unable to deliver oxygen to the cells of the body.

34. Vitamins for Healthy Blood
Folate and Birth Defects
Plays a crucial role in a healthy pregnancy.
Reduces the risk of bearing a baby with a type of birth defect called a neural tube defect.
Like spina bifida

35. Vitamins for Healthy Blood
Sources of Folate
The Food and Drug Administration has mandated that all enriched grain products be fortified with folic acid to improve intakes in the United States population.

36. Vitamins for Healthy Blood
B Vitamins and Heart Disease
Low intakes of folate, vitamin B12, and vitamin B6 are linked to increased risk of heart attack or stroke.
Increased levels of homocysteine in blood.
Enhanced blood clot formation and damage to arterial walls.
Homocysteine may be toxic to the brain.

37. Vitamins for Healthy Blood
Vitamin B12
Maintains the sheaths that surround and protect nerve fibers.
Works closely with folate, enabling it to manufacture red blood cells.
A vitamin B12 deficiency can prevent folate from building healthy red blood cells, resulting in anemia.
Treatment with folate will cure the anemia but mask the vitamin B12 deficiency.

38. Vitamins for Healthy Blood
Vitamin B12
Deficiencies are unlikely for individuals who consume animal-based foods.
Some groups at risk of deficiency include:
Strict vegetarians.
Those with a genetic defect that leaves the body unable to make a compound known as intrinsic factor.
And those elderly who may develop atrophic gastritis.

39. Vitamins for Healthy Blood
Sources of Vitamin B12

40. Vitamins for Healthy Blood
Vitamin B6
Functions as a coenzyme.
Helps make hemoglobin for red blood cells.
Plays a role in protein metabolism.
Requirements are proportional to protein intake.
Deficiency symptoms:
Weakness
Irritability
Insomnia

42. Vitamins for Healthy Blood
Sources of Vitamin B6

43. Vitamins for Healthy Blood
Vitamin K
Key function: its role in the blood-clotting system of the body.
Works with vitamin D to help regulate the calcium levels in the blood.
Is obtained both in the diet and via the intestinal bacteria, making deficiencies rare.
Newborn babies are the one group that is commonly susceptible to a vitamin K deficiency.
A baby’s digestive tract is free of bacteria until birth.

45. Vitamins for Healthy Blood
Sources of Vitamin K

46. Color Your Plate with Vitamin Rich Foods
Shop at least once a week
Store most fruits and vegetables whole in the frig
Eat within a month of purchase
Cook in the least amount of water and for the shortest time

47. Vitamins for Healthy Bones
Bones are made up of a matrix of living tissue based on collagen, into which the crystals of bone minerals are deposited.
Calcium and phosphorus are the principle bone minerals in the matrix.
Bones undergo remodeling throughout life but peak bone mass is reached at about 30 years of age.
Vitamins essential for healthy bones:
Vitamin D
Vitamin K
Vitamin B12

48. Vitamins for Healthy Bones
Electron micrograph of healthy trabecular bone
Electron micrograph of trabecular bone affected by osteoporosis

49. Vitamins for Healthy Bones
Bone Making and Maintenance Team
Vitamin D directs the team consisting of:
Vitamins: vitamin C and vitamin K
Hormones
Protein: collagen
Minerals: calcium, phosphorus, magnesium, and fluoride (Chapter 8)

50. Vitamins for Healthy Bones
Vitamin D
Assists the absorption of dietary calcium.
Helps to make calcium and phosphorus available in the blood so these minerals can be deposited into bone.
Acts much like a hormone, exerting influence on other organs like kidneys and the intestines.

51. Vitamins for Healthy Bones
Vitamin D
Regardless of dietary consumption, the body can synthesize vitamin D with the help of sunlight.
The liver makes a vitamin D precursor and with the help of the sun’s ultraviolet rays, it becomes an active form of vitamin D.
Vitamin D is the sunshine vitamin

52. Vitamins for Healthy Bones
Vitamin D Deficiency:
Needs can be met through diet or sun exposure.
Sun exposure of face, hands and arms for 5-15 minutes several times per week will meet needs.
Deficiency risk includes:
Living in northern climate.
Institutionalized or housebound elderly people.
Deficiency disease:
In children, rickets.
In adults, osteomalacia.
Bones become soft, porous, and weak

53. Vitamins for Healthy Bones
Only a few foods contain vitamin D

54. Vitamins for Healthy Bones
Vitamin K
Works in conjunction with vitamin D to synthesize a bone protein that regulates the calcium levels in the blood.
Low levels have been associated with low bone mineral density and hip fracture in older women

55. Vitamins for Energy Metabolism
When the body needs energy it breaks down glycogen to glucose, triglycerides to fatty acids & glycerol, or protein to amino acids.
When the body does not need energy, it builds glycogen, body proteins, or body fat.
Many vitamins and minerals are essential for energy metabolism.

56. Vitamins for Energy Metabolism
Thiamin
Riboflavin
Niacin
Vitamin B6
Folate
Vitamin B12
Pantothenic acid
Biotin

57. Vitamins for Energy Metabolism
Thiamin
One of the B vitamins.
Acts primarily as a coenzyme in reactions that release energy from carbohydrate.
Plays a crucial role in nerve processes
Beriberi
The thiamin deficiency disease, characterized by irregular heartbeat, paralysis, and extreme wasting of muscle tissue.

58. Vitamins for Energy Metabolism
Sources of Thiamin

60. Vitamins for Energy Metabolism
Riboflavin
Also one of the B vitamins.
Acts as a coenzyme in energy-releasing reactions in the body.
Helps to prepare fatty acids and amino acids for breakdown.
Deficiencies of the vitamin (rare), are characterized by severe skin problems, including painful cracks at the corners of the mouth; a red, swollen tongue; and teary or bloodshot eyes.

61. Vitamins for Energy Metabolism
Sources of Riboflavin

62. Vitamins for Energy Metabolism
Niacin
Also one of the B vitamins.
Also part of a coenzyme vital to obtaining energy.
Recall that pellagra is the deficiency disease.

63. Vitamins for Energy Metabolism
Can be made from the amino acid tryptophan in the body.
60 milligrams of tryptophan yield 1 milligram of niacin.
Thus, the DRI for niacin is expressed in niacin equivalents (NE).

64. Vitamins for Energy Metabolism
Sources of Niacin

65. Vitamins for Energy Metabolism
Pantothenic acid and biotin
Both are B vitamins needed to synthesize coenzymes that are active in many body systems.
Biotin is required for cell growth, synthesis of DNA, and maintenance of blood glucose levels.
Both are widespread in foods, so people who eat a varied diet are not at risk for deficiencies.

66. Vitamins for Energy Metabolism
Sources of Biotin and Pantothenic Acid

67. Phytonutrients in Foods
Phytochemicals Physiologically active compounds found in plants that are not essential nutrients but that appear to help promote health and reduce risk for cancer, heart disease, and other conditions.
Also called phytonutrients.
phyto = plant
Cruciferous vegetables, such as cauliflower, broccoli, and Brussels sprouts, contain nutrients and nonnutrients that protect against cancer.

68. Phytonutrients in Foods
Give plants their brilliant colors and distinct aromas
Found in edible parts of plants including fruits, vegetables, & whole grains.
They do not provide energy or building material.
Ongoing research indicates they act as powerful antioxidants, decreasing blood pressure & cholesterol, preventing cataracts, reducing menopause symptoms & risk for osteoporosis, & slowing or reversing certain cancers.

69. Phytonutrients in Foods
Many foods contain numerous phytochemicals, each one acting on one or several mechanisms.
Antioxidant properties - protect against harmful cell damage.
Anticancer properties - preventing initiation and promotion of cancer.
Anti-estrogen properties - blocking action of estrogen and lowering risk of some cancers.
May protect against other diseases
Heart disease, eye disease, osteoporosis and cancer

70. Phytonutrients in Foods
Optimizing Intake of Phytochemicals
Pure extracts in supplements are less effective than phytochemicals in whole food.
Absorption, metabolism, distribution, and function depends on the combination of phytochemicals and other substances naturally occurring in food.
Until more is known, it is best to follow recommendations of MyPlate for fruit, vegetables, whole grains, soy foods, legumes, nuts, and seeds.

71. Choosing a Vitamin-Mineral Supplement
Remember most people should be able to get all needed nutrients from diet
Particular groups of people may need supplementation

72. Keep these points in mind when choosing a supplement
Remember that price is not an indication of quality.
Look for a supplement that contains both vitamins and minerals, with no more than 100 percent to 150 percent of the recommended Daily Values for each.
Buy products sold in childproof bottles or packages if you have children around.

73. Nutrition & Cancer Prevention

74. ````````````` Genetic and related risk factors (Total) 14%
Family history of cancer 5%
Perinatal factors/growth 5%
Reproductive factors 3%
Prescription drugs/medical procedures 1%
Lifestyle risk factors (Total) 77%
Tobacco use 30%
Adult diet/obesity 30%
Sedentary lifestyle 5%
Occupation/job-related factors 5%
Alcohol 3%
Socioeconomic status 3%
Salt/food additives, and other
preservatives/contaminants 1%
Environmental
risk factors
(Total) 9%
Viruses/other
biologic agents 5%
Pollution 2%
Ionizing/ultraviolet
radiation 2%
Figure 7.4: The Impact of Genetic, Environmental, and Lifestyle Risk Factors on Cancer.
SOURCES: American Institute for Cancer Research, Stopping Cancer Before It Starts: The American Institute for Cancer Research’s Program for Cancer Prevention (New York: Golden Books, 1999), 10; Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective (Washington, D.C.: World Cancer Research Fund/American Institute for Cancer Research), 2007.

75. Cancer initiation: Initiation by a carcinogen causes cancerous alterations in previously healthy body cells.

76. pollution/contaminants
Examples of Carcinogens
A. Cancer initiation. Initiation by a carcinogen causes cancerous alterations in
previously healthy body cells.
Cancer initiation
Ultraviolet light/
radiation
Cigarettes
Healthy
body cells
Damaged cellular
DNA and altered
genetic material
Development of
cancerous cells
Toxic environmental
pollution/contaminants

77. Cancer promotion: Cancer promoters enhance the growth of abnormal cancerous cells.

78. B. Cancer promotion. Cancer promoters enhance the growth of abnormal
cancerous cells.
Cancer promotion
Cancerous cells
Cancer progression
Examples of Cancer Promoters:
Ultraviolet
light/radiation
Toxic environmental
pollution/contaminants
Lack of physical
activity and obesity
Cigarettes
Excess alcohol
Excess dietary fat

79. Cellular repair: Cancer antipromoters squelch free radical damage and enhance the body’s ability to repair damaged DNA strands.

80. and phytochemical team and healthy body weight
C. Cellular repair. Cancer antipromoters squelch free radical damage and
enhance the body’s ability to repair damaged DNA strands.
Cellular repair
Damaged cellular
DNA and altered
genetic material
Healthy
body cells
Examples of Cancer Antipromoters:
The antioxidant, fiber,
and phytochemical team
Strong immune system
and healthy body weight

81. Factors that Decrease or Increase Cancer Risk

83. Nutrition & Cancer Prevention
1. Be as lean as possible without becoming underweight.
2. Be physically active for at least 30 minutes every day.
3. Avoid sugary drinks. Limit consumption of energy-dense foods
4. Eat more of a variety of vegetables, fruits, whole grains, and legumes such as beans.
5. Limit consumption of red meats (such as beef, pork, and lamb) and avoid processed meats.

84. Nutrition & Cancer Prevention
6. If you do drink alcohol, limit your consumption to no more than two drinks a day for men and one drink a day for women. 7. Limit consumption of salty foods and foods processed with salt (sodium). 8. Don’t use supplements to protect against cancer. 9. And always remember—do not smoke or chew tobacco.