Lecture 7: Fundamentals of Nutrition Part 2

Question 1

What is the function of Vitamin D?

Answer 1

Induce calcium absorption and synthesis of calcium binding proteins

Question 2

What is the active form of Vitamin D?

What is the storage form of Vitamin D?

Answer 2

Active: 1,25-dihydroxy Vitamin D (Calcitriol)
Storage: 25-hydroxy Vitamin D (Calcidiol) in liver

Question 3

What can result from a Vitamin D deficiency?

Answer 3

Childhood rickets

Adult osteomalacia

Question 4

What does thiamine (B1) do?

Answer 4

Plays a role in the conversion of pyruvate to Acetyl CoA

Also plays role in branched chain amino acids and transketolase (PPP shunt)

Question 5

What can result from a thiamine deficiency?

Answer 5

Wernicke-Korsakoff syndrome

Dry Beriberi: muscle wasting, partial paralysis
Wet beriberi: peripheral edema, cardiac failure

*Alcoholism interferes with absorption

Question 6

What does riboflavin (B2) do?

Answer 6

Coenzymes for FAD/FMN

• dehydrogenases
• oxidation/reduction reactions

Question 7

What can result from a riboflavin deficiency?

Answer 7

Normally accompanied with other deficiencies

• sore throat
• hyperemia of pharyngeal mucous membranes

Question 8

What does niacin (B3) do?

Answer 8

Coenzymes for NADH/NADPH

-metabolism reactions for carbohydrates, fatty acids, and proteins (tryptophan)

Question 9

What can result from a niacin deficiency?

Answer 9

Pellagra: diarrhea, dementia, dermatitis, death

Hartnup Disease: impaired tryptophan absorption

Question 10

What does pantothenic acid (B5) do?

Answer 10

Synthesis of Coenzyme A

• Vitamin A, Vitamin D, cholesterol steroids
• First step in TCA cycle by forming citrate

Question 11

What can result from a pantothenic acid deficiency?

Answer 11

Very rare

• dermatitis
• numbness
• paresthesia
• dysesthesia (burning feet syndrome)

Question 12

What does pyridoxine (B6) do?

Answer 12

Regulate Aminotransferase reactions (ALT and AST)

Convert tryptophan to niacin

Question 13

What can result from a pyridoxine deficiency?

Answer 13

Sideroblastic anemia
Dermatitis

Toxicity: peripheral neuropathy, dermatoses, photosensitivity dizziness, and nausea

Question 14

What does biotin (B7) do?

Answer 14

Important for carboxylation enzymes

• Acetyl-CoA carboxylase
• Pyruvate carboxylase
• Propionyl CoA carboxylase

Question 15

What can result from a biotin deficiency?

Answer 15

Results from excessive consumption of raw eggs due to avidin

• dermatitis around eyes, nose, and mouth
• alopecia

Question 16

What does folic acid (B9) do?

Answer 16

Important for de novo pyrimidine synthesis

Question 17

What can result from a folic acid deficiency?

Answer 17

Can cause issues in pregnancy: spina bifida
Macrocytic megaloblastic anemia
Homocysteinemia

Question 18

What does cobalamin (B12) do?

Answer 18

Converts coenzymes
Homocysteine –> methionine
Methylmalonyl-CoA –> Succinyl CoA

Question 19

What can result from a cobalamin deficiency?

Answer 19

Normally from vegetarian diet

Megaloblastic anemia
Neuropathies
Homocysteinemia

Question 20

What does ascorbic acid (Vitamin C) do?

Answer 20

Important for collagen synthesis, neurotransmitter synthesis, fatty acid transport, etc

Question 21

What can result from a Vitamin C deficiency?

Answer 21

Scurvy

Question 22

What does Vitamin E do?

Answer 22

Anti-oxidant free radical scavenger

Question 23

What does Vitamin K do?

Answer 23

Involved in carboxylation of glutamate residues and essential for proper blood clotting

Question 24

What does Vitamin A do?

Answer 24

Vision and maintenance of epithelium