Vitamins

Question 1

Lipid soluble vitamins

Answer 1

• A, D, K, E

- Deficiencies don’t arise as quickly and toxicity may be a problem

Question 2

Water soluble vitamins

Answer 2

• B vitamins and vitamin C

- Deficiencies arise more quickly and less likely to be toxic

Question 3

Vitamin A Functions

Answer 3

-Visual cycle (rhodopsins and cone opsins), glycoprotein and mucopolysaccharide synthesis, retinoic acid, antioxidant

Question 4

Vitamin A Deficiency signs

Answer 4

• Night blindness
• Xerophthamia
• Follicular hyperkeratosis
• Anemia
• Poor growth
• Increased susceptibility to infection and cancer

Question 5

Vitamin A toxicity

Answer 5

• Accumulates in the liver

- Nausea, diarrhea, bone pain, scaly skin, orange tint of skin

Question 6

Vitamin A family

Answer 6

• All trans retinol

- Includes carotenoids that are pro-vitamins

Question 7

Vitamin D Functions

Answer 7

• Maintain bone
• Calcium homeostasis
• Acts as a hormone

Question 8

Vitamin D Deficiency

Answer 8

• Rickets in children
• Osteomalacia in adults
• Increased susceptibility to some cancers

Question 9

Synthesis of Vitamin D

Answer 9

• Requires skin, liver, and kidney
• 7-dehydrocholesterol–>Cholecalciferol–>25-hydroxycholecalciferol–>1,25-hydroxycholecalciferol
• Active D3=Calcitrol

Question 10

Vitamin D toxicity

Answer 10

• Rare

- Leads to high serum levels of calcium and bone loss

Question 11

Vitamin D and Cancer

Answer 11

-Low serum vitamin D levels correlated with increased risk of breast cancer

Question 12

Vitamin K Function

Answer 12

• Localization of enzymes required for blood clotting

- Catalyzes addition of gamma-carboxyglutamate to clotting enzymes

Question 13

Vitamin K deficiency

Answer 13

-Easy bruising, bleeding, hemorrhage

Question 14

Vitamin K synthesis

Answer 14

• Involves bacteria in gut

- This is why newborns may be vitamin K deficient

Question 15

Vitamin E function

Answer 15

• Antioxidant: scavenges free radicals
• Protects membranes from damage
• Prevents oxidation of LDL

Question 16

Vitamin E deficiency

Answer 16

• Cardiovascular disease

- Neurological symptoms

Question 17

Vitamin E family

Answer 17

-Closely related to tocopherols and tocotrienols

Question 18

Vitamin C function

Answer 18

• Ascorbic acid
• Cofactor for oxidases involved in collagen formation (hydroxylation of proline and lysine)
• Required for synthesis of steroids in stress response
• Aids iron absorption
• Has antioxidant activity

Question 19

Vitamin C deficiency

Answer 19

• Bruising
• Immunocompromised
• Scuvy (decreased wound healing, osteoporosis, hemorrhage, anemia, fatigue)

Question 20

Characteristics of scurvy

Answer 20

• Corkscrew hairs
• Pinpoint hemorrhages
• Periodontal disease

Question 21

Vitamin C toxicity

Answer 21

• Rare
• GI upset
• Kidney stones

Question 22

Energy releasing B vitamins

Answer 22

• B1: Thiamine
• B2: Riboflavin
• B3: Niacin
• B5: Pantothenic acid
• B6: Pyroxidine
• B7: Biotin

Question 23

Hematopoietic B vitamins

Answer 23

• B9: Folate

- B12: Cobalamin

Question 24

Common effects of deficiencies in energy releasing B vitamins

Answer 24

• Dermatitis
• Swollen red tongue: glossitis
• Diarrhea
• Peripheral neuropathy
• Depression, confusion
• Lack of coordination
• Malaise

Question 25

B1 Functions

Answer 25

- Thiamine - Precursor of TPP - Required cofactor for several enzymes in cellular energy metabolism - Critical in nervous system

Question 26

B1 Deficiency

Answer 26

- GI, depression, fatigue - Wernicke-Korsakoff syndrome - Beriberi

Question 27

Three enzymes that use TPP in metabolism

Answer 27

- Transketolase/transaldolase - Pyruvate dehydrogenase - alpha-ketoglutarate dehydrogenase

Question 28

Wernicke-Korsakoff Syndrome

Answer 28

- Thiamine deficiency seen in chronic alcoholics - Mental disturbance, unsteady gate, uncoordinated eye movements - Occasionally congestive heart failure

Question 29

Beriberi

Answer 29

- Very severe thiamine deficiency - Extreme muscle weakness - Poly-neuropathy - Heart failure - Sometimes edema (wet and dry beriberi exist)

Question 30

B2 Function

Answer 30

- Riboflavin - Precursor of FAD and FMN - Key coenzyme for redox reactions in metabolism

Question 31

B2 Deficiency

Answer 31

- Ariboflavinosis--rash around nose, inflammation of mouth and tongue, burning and itchy eyes, light sensitivity - Alcoholics get it sometimes but it's pretty rare

Question 32

B3 Function

Answer 32

- Niacin - Precursor of NAD and NADP coenzymes important in redox reactions of energy metabolism - Given to patients with hypercholesterolemia or hypertriglyceridemia

Question 33

B3 Deficiency

Answer 33

- Pellagra: dermatitis, diarrhea, dementia, death - People with corn or millet based diets are susceptible - Treat with tryptophan or niacin supplementation

Question 34

B7 Function

Answer 34

- Biotin | - Coenzyme for some carboxylases

Question 35

B7 Deficiency

Answer 35

- Rare | - Can be caused by eating a lot of rare eggs (contain avidin--binds biotin tightly)

Question 36

B5 function

Answer 36

- Pantothenic acid - Required for synthesis of CoA - Required for TCA cycle and metabolism of all fats and proteins

Question 37

B5 Deficiency

Answer 37

- Very rare | - Typical B vitamin deficiency symptoms

Question 38

B6 Function

Answer 38

- Pyridoxine - Precursor of pyridoxyl phosphate (PLP) enzyme cofactor - Required for glycogen breakdown and synthesis of GABA and heme

Question 39

B6 Deficiency

Answer 39

- Mild irritability, nervousness, depression - Peripheral neuropathy, convulsions, decreased glucose tolerance, hyperhomocystenemia, anemia - People treated with isoniazid are susceptible