Vitamin Basics and Water-soluble Vitamins

Question 1

List the fat-soluble and water-soluble vitamins

Answer 1

Fat-soluble: Vitamin A, D, E, K
Water-soluble: Vitamin B, C

Question 2

Why is vitamin intake important for humans?

Answer 2

Vitamins cannot be endogenously synthesized in the human body unlike other organisms

Question 3

Where can you find fat-soluble and water-soluble vitamins in the body?

Answer 3

Fat-soluble vitamins: More protein bound, stored in tissue
Water-soluble vitamins: Less protein bound, remain in the bloodstream

Question 4

Why do most water-soluble vitamins need to be replenished on a daily basis?

Answer 4

They are usually circulating in blood and can be more easily excreted by the kidneys

Question 5

Outline the basic roles of each vitamin

Answer 5

A: Immunity (Make WBCs), Shape bones, Improve vision

B: Coenzyme to release energy from food

C: Fight infection and form collagen

D: Bone formation from Calcium and Phosphorous

E: Antioxidant

K: Blood clotting

Question 6

Which vitamins can be synthesized in the human body? (Exceptions)

Answer 6

Pre-vitamin D3: Skin, UV

Vitamin K2 and B12: Colonic microbes

Question 7

Vitamin B1
- Name
- Source
- Deficiency state

Answer 7

Thiamine:
- Yeast, Pork, Brown rice, cereals from whole grains
- Beriberi and Wernicke-Korsakoff syndrome

Question 8

Vitamin B1 MOA

Answer 8

• Coenzyme to catalyze pyruvate to acetyl-CoA;
• Glutamate & GABA synthesis;
• Myelin sheath maintenance

Question 9

Does Vitamin B1 have any toxicity issues?

Answer 9

No, the kidneys can rapidly clear almost all excess thiamine and because thiamine is not stored

Question 10

Vitamin B2
- Name
- Source
- Deficiency state

Answer 10

• Riboflavin
• Milk, eggs, meat, fish, green vegetables
• Ariboflavinosis (Mild and non-specific symptoms)

Question 11

Vitamin B2 MOA

Answer 11

Coenzyme in cellular metabolic pathways
- TCA cycle
- Beta oxidation of fatty acids

Question 12

What are some therapy indications of Vitamin B2?

Answer 12

Intramitochondrial beta-oxidation defects like MADD

HIV infection treated with zidovudine to reverse the development of lactic acidosis

Question 13

Does Vitamin B2 have any toxicity issues?

Answer 13

No, water-solubility limits absorption of excess vitamin B2

Question 14

Vitamin B3
- Name
- Source
- Deficiency state

Answer 14

Niacin (Nicotinic acid and nicotinamide)
- Plant and animal food (Yeast, meat especially liver, grains, corns, seeds)
- Pellagra (Photosensitive pigmented dermatitis)

Question 15

Vitamin B3 MOA

Answer 15

Niacin forms NAD and NADP

Niacin moiety accepts electrons or donate hydrogen ions involved in NAD-dependent enzyme reactions like oxidation of fatty acids, glycolysis, TCA cycle

Question 16

Does Vitamin B3 have any toxicity issues?

Answer 16

Flushing reaction, N/V, pruritus, hives, elevated ALT/AST from dose-dependent toxicity

Crystalline nicotinic acid

Question 17

What are the therapeutic roles of niacin?

Answer 17

Total and LDL Cholesterol lowering agent

Question 18

Vitamin B5
- Name
- Source
- Deficiency state

Answer 18

Pantothenic acid
- Egg yolk, liver, kidney, broccoli, milk, chicken, beef, potatoes, whole grains
- Rare (Paresthesia, dysesthesia, burning feet syndrome)

Question 19

Vitamin B5 MOA

Answer 19

Forms CoA required in the synthesis and degradation of vitamin A, D, cholesterol, steroids, fatty acids, carbohydrates, proteins

TCA cycle binding to oxaloacetate to form citrate

Activate and inactivate peptide hormones

Question 20

Vitamin B6
- Name
- Source
- Deficiency state

Answer 20

Pyridoxine
- Plant food predominantly
- Rare (Peripheral neuropathy, stomatitis, glossitis, irritability, confusion, depression)

Question 21

Vitamin B6 MOA

Answer 21

Gluconeogenesis of amino acids

Conversion of tryptophan to niacin

Heme synthesis

Neurotransmitter synthesis

Steroid hormone modulation

Question 22

Does Vitamin B6 have toxicity concerns?

Answer 22

Megadoses lead to peripheral neuropathy, photosensitivity, dizziness, nausea

Question 23

Vitamin H
- Name
- Type of vitamin (fat/water)
- Source
- Deficiency

Answer 23

Biotin
- Water-soluble
- Found in plants mainly, liver, egg yolk, soybean products, yeast
- Nutritional deficiency and multiple carboxylase deficiency

Question 24

Does vitamin H have any toxicity concerns?

Answer 24

No

Question 25

Vitamin C
- Name
- Source
- Deficiency state

Answer 25

Ascorbic acid
- Citrus fruits, tomatoes, potatoes, cauliflower, spinach
- Scurvy (Cutaneous signs due to impaired collagen synthesis), gingivitis, arthralgias, impaired wound healing

Question 26

What therapeutic indications do vitamin C have?

Answer 26

Prevention of CVD and cancer BUT no evidence support

NO ROLE in common cold prevention

Question 27

Does Vitamin C have any toxicity concerns?

Answer 27

Large doses can lead to diarrhea and abdominal bloating

Correlates with oxalate kidney stones in males

Question 28

List other vitamins and pseudovitamins

Answer 28

Choline
InositolCarnitine
Lipoic acid
Lutein
Zeaxanthin
Carotenoids

Question 29

Vitamin B12
- Name
- MOA
- Deficiency state

Answer 29

Cyanocobalamin
- Coenzyme for metabolic functions like fat and carbohydrate metabolism, protein synthesis, cell replication (Red blood cell formation)
- Pernicious anemia, dietary deficiency from malabsorption etc.