Vitamin Basics and Water-soluble Vitamins Flashcards
List the fat-soluble and water-soluble vitamins
Fat-soluble: Vitamin A, D, E, K
Water-soluble: Vitamin B, C
Why is vitamin intake important for humans?
Vitamins cannot be endogenously synthesized in the human body unlike other organisms
Where can you find fat-soluble and water-soluble vitamins in the body?
Fat-soluble vitamins: More protein bound, stored in tissue
Water-soluble vitamins: Less protein bound, remain in the bloodstream
Why do most water-soluble vitamins need to be replenished on a daily basis?
They are usually circulating in blood and can be more easily excreted by the kidneys
Outline the basic roles of each vitamin
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
Which vitamins can be synthesized in the human body? (Exceptions)
Pre-vitamin D3: Skin, UV
Vitamin K2 and B12: Colonic microbes
Vitamin B1
- Name
- Source
- Deficiency state
Thiamine:
- Yeast, Pork, Brown rice, cereals from whole grains
- Beriberi and Wernicke-Korsakoff syndrome
Vitamin B1 MOA
- Coenzyme to catalyze pyruvate to acetyl-CoA;
- Glutamate & GABA synthesis;
- Myelin sheath maintenance
Does Vitamin B1 have any toxicity issues?
No, the kidneys can rapidly clear almost all excess thiamine and because thiamine is not stored
Vitamin B2
- Name
- Source
- Deficiency state
- Riboflavin
- Milk, eggs, meat, fish, green vegetables
- Ariboflavinosis (Mild and non-specific symptoms)
Vitamin B2 MOA
Coenzyme in cellular metabolic pathways
- TCA cycle
- Beta oxidation of fatty acids
What are some therapy indications of Vitamin B2?
Intramitochondrial beta-oxidation defects like MADD
HIV infection treated with zidovudine to reverse the development of lactic acidosis
Does Vitamin B2 have any toxicity issues?
No, water-solubility limits absorption of excess vitamin B2
Vitamin B3
- Name
- Source
- Deficiency state
Niacin (Nicotinic acid and nicotinamide)
- Plant and animal food (Yeast, meat especially liver, grains, corns, seeds)
- Pellagra (Photosensitive pigmented dermatitis)
Vitamin B3 MOA
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
Does Vitamin B3 have any toxicity issues?
Flushing reaction, N/V, pruritus, hives, elevated ALT/AST from dose-dependent toxicity
Crystalline nicotinic acid
What are the therapeutic roles of niacin?
Total and LDL Cholesterol lowering agent
Vitamin B5
- Name
- Source
- Deficiency state
Pantothenic acid
- Egg yolk, liver, kidney, broccoli, milk, chicken, beef, potatoes, whole grains
- Rare (Paresthesia, dysesthesia, burning feet syndrome)
Vitamin B5 MOA
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
Vitamin B6
- Name
- Source
- Deficiency state
Pyridoxine
- Plant food predominantly
- Rare (Peripheral neuropathy, stomatitis, glossitis, irritability, confusion, depression)
Vitamin B6 MOA
Gluconeogenesis of amino acids
Conversion of tryptophan to niacin
Heme synthesis
Neurotransmitter synthesis
Steroid hormone modulation
Does Vitamin B6 have toxicity concerns?
Megadoses lead to peripheral neuropathy, photosensitivity, dizziness, nausea
Vitamin H
- Name
- Type of vitamin (fat/water)
- Source
- Deficiency
Biotin
- Water-soluble
- Found in plants mainly, liver, egg yolk, soybean products, yeast
- Nutritional deficiency and multiple carboxylase deficiency
Does vitamin H have any toxicity concerns?
No
