Vitamins and Dietary Supplements

Question 1

What are vitamins?

Answer 1

Vitamins are organic compounds that people need in small quantities. Most vitamins need to come from food because the body either does not produce them or produces very little.

• Not an energy source
• Individual units rather than long chains
• Essential for normal functioning, growth, and maintenance of the body

Question 2

Vitamin Content in food depend on (3)? How is this different in plants (4)?

Answer 2

• Source
• Packaging and storage
• Levels of processing
• For plants: Sunlight, moisture, growing conditions, maturity at harvest

Question 3

Which Vitamins are Fat Soluble, and which are water soluble?

Answer 3

Fat Soluble A-E-D-K

Water Soluble B-C

Question 4

How are fat-soluble (AEDK) vitamins and water-soluble vitamins(BC) digested?

Answer 4

Fat Soluble
In the mouth to break foods into smaller pieces to release vitamins.
In the stomach, digestive enzymes work to release vitamins from food.
Bile is required to emulsify fat and aid digestion and absorption.

Water Soluble
In the mouth to break down food to release vitamins.
In the stomach, digestive enzymes work to release vitamins from food.

Question 5

How are fat-soluble (AEDK) vitamins and water-soluble vitamins(BC) absorbed?

Answer 5

Fat Soluble
Occurs in the small intestine. Inside the intestinal cell, they are packaged in chylomicrons and move to lymphatic circulation before being transported by the blood.

Water soluble
Occurs in small intestine, similar to glucose and amino acids, directly into blood.

Question 6

How are fat-soluble (AEDK) vitamins and water-soluble vitamins(BC) transported?

Answer 6

Fat Soluble
Transported by protein carriers (lipoprotein) through watery compartments of the body

Water Soluble
Travel freely in watery compartments of the body

Question 7

How are fat-soluble (AEDK) vitamins and water-soluble vitamins(BC) stored?

Answer 7

FAT SOLUBLE
Liver or fatty tissue such as adipose tissue
Provitamins must be activated for example beta carotene to vitamin A

Water soluble
Not stored in the body, with exception to vitamin B12 in the liver

Question 8

What is the dietary requirement difference in fat-soluble and water-soluble vitamins?

Answer 8

Fat Soluble
Daily intake is not required because of body storage
Water soluble
Regular intake is required and varies by vitamin because the body does not usually store large amounts.

Question 9

Which type of vitamin is vulnerable to cooking?

Answer 9

Water-soluble vitamins are Vulnerable to cooking
Boiling 35-60%
Frying 7-10%

Question 10

What are the active forms (retinoids) and precursors of Vitamin A?

Answer 10

Active forms (retinoids)
Retinol, Retinal, Retinoic Acid
Found in animal source

Precursors (Carotenoids)
Plant Pigments
Act as antioxidant
Beta-carotene and lycopene
Body absorbs 20 - 40% of carotenoids, dietary fat, protein, vitamin E, quick cooking enhance absorption

Question 11

Where is Vitamin A stored?

Answer 11

Liver stores 90% of vitamin A
Can store up to a year’s supply
Retinol Binding protein carries retinol released by the liver

Question 12

What is the function of Vitamin A?

Answer 12

Vision: changes incoming light to visual images, forms rhodopsin which signals electrical information to the brain.
Bone Health: Needed for bone growth and remodelling
Reproduction: Sperm production, female fertility
Immune Function

Question 13

What is the source of Vitamin A? RDI?

Answer 13

Animal source 70-90%: Retinoids
Plant Source 9-22%: provitamin A carotenoids
In small interesting carotenoids → Retinol → Transported by chylomicrons to the lymphatic system → storage in liver
Dietary intake: 800-680 microgram retinol for men or women

Question 14

What is vitamin D? What are the two different type

Answer 14

Similar to hormone
D2 ergocalciferol, cheap
D3 cholecalciferol, more effective

Question 15

What is the Function of Vitamin D?

Answer 15

Functions:	
Regulation of osteoblast and osteoclast equilibrium
Regulation of cell differentiation
Prevention of cancer cell division
Anti Inflammatory properties
Regulation of insulin production

Question 16

What is the source of Vitamin D?

Answer 16

Provitamin D3 in the skin (a cholesterol) became active through UV light
Vitamin D3 and D2 are absorbed with fats, incorporated with chylomicrons to the lymphatic system to the liver, where it is stored as calcidiol
Parathyroid hormone activates calcidiol to calcitriol.

Question 17

What medical illnesses are associated with vitamin D Malnutrition?

Answer 17

Rickets and osteomalacia and osteoporosis

Hypercalcemia

Question 18

Characteristics of Vitamin E? Absorption, Storage, Function, RDI, Sources?

Answer 18

Alpha-tocopherol
Absorption: GI tract (20-80%)
Storage: Adipose tissue
Functions: Antioxidant
RDA (15mg/day)
Sources: Nuts, seeds, vegetable oil, whole grain, wheat germ oil, fruit, vegetables.
Deficiency and toxicity are rare

Question 19

Characteristics of Vitamin K? Absorption, Storage, Function, RDI, Sources?

Answer 19

Quinones
Absorption GI Tract
Storage Liver
Functions: Promotes Blood clotting
RDA 120 - 90
Sources: leafy greens and intestinal bacteria
Deficiencies and toxicities are rare

Question 20

What is the function of Vitamin B12 (Cobalamin)?

Answer 20

Functions:
DNA and red blood cell synthesis
Maintains myelin sheath around nerves

Question 21

How is Vitamin B12 absorbed?

Answer 21

R-protein from salivary glands
Intrinsic Factor from stomach cells
B12+R-protein complex in the stomach
Pancreatic enzymes degrade R-protein in the small intestine: B12 is released and can bind with the intrinsic factor (B12+IF complex)
B12+IF complex binds to intestinal cell receptor and absorbed in the ileum
Requires adequate stomach acid and intrinsic factor
The only water-soluble vitamin that can be stored in the liver

Question 22

What are the sources of Vitamin B12?

Answer 22

Only animal foods
Animals obtain it from bacteria on their food or from their intestinal bacteria
Fortified Foods, such as cereal, milk substitutes and some soy products.

Question 23

How is long is Vitamin B12 stored in the body?

Answer 23

Enough Vitamin B12 to last 2 years
Symptoms of deficiency may not appear till 12 years later
Most deficiency is caused by inadequate intake or impaired absorption

Question 24

What is Pernicious Anemia?

Answer 24

A form of anaemia from an autoimmune disorder that damages cells lining the stomach (IF reduced) and inhibits vitamin B12 absorption

Question 25

Characteristics of Vitamin C? Function, Source, RDI, Deficiency?

Answer 25

Function
Antioxidant and reducing agent
Collagen function
Enhances absorption of nonheme iron in plant foods
Source: 75mg/day
Fruits and vegetables
Deficiency:
Scurvy: reopening of wounds, bleeding gums, bone pain

Question 26

Which population require dietary supplements?

Answer 26

Women of childbearing age who may become pregnant
Pregnant and breastfeeding women
Women with heavy menstrual losses
Children
Infants
People with severe food restrictions
Strict Vegetarians
Old people

Question 27

What is megadosing? Where is it used? What is the drawback?

Answer 27

Megadoses
High levels of supplementation
Uses in limited and specific cases: example malabsorption syndromes such as pernicious anemia
Achieving the optimal nutrition level
Drawbacks of megadoses
Can act as a drug
Can create deficits of other nutrients
Can interfere with absorption of others