Fat-Soluble Vitamins

Question 1

Discovery of Vitamin A:

Answer 1

• cures for night blindness w liver already known by egyptians and hypocrites
• 1850s eduard schwarz: ox liver to night blinded sailors
• elmer mcollum and margeurite davis: both factor a (vit a) and b needed for growth in rats (why b fixed scaliness and shit but did not lead to growth)

Question 2

What are animal sources of vitamin A called?

What are plant sources called?

Answer 2

animal: retinol and retinyl esters (pre-formed vit A)
plant: carotenoids (provit A)

Question 3

Causes and effects of vitamin A deficiency:

Answer 3

causes:
- dietary

effects:
- night blindness
- xerophthalmia (drying of the corneas because of lack of transcription which affects epithelial cells)
- keratinization of mucous-forming cells
- infection (lower immune system, again b/c of lack of cell differentiation to make different immune cells)

Question 4

Functions of vitamin A:

Answer 4

• vision
• cell differentiation (growth, reproduction, bone growth, epithelial cell formation, immunity)
• b/c of cell differentiation, crucial for maintaining integrity of epithelial surfaces (eye, skin, trachea, salivary gland, vaginal epithelium, GI tract)
• regulatory role in transcription: retinoic acid (a form of vitamin A) tells retinoic acid response element (RARE: a nucleotide sequence that stops transcription) to keep going and continue transcription
• used in accutane to treat acne and retin-A to tighten skin
• antioxidant (retinol)

Question 5

What’s the deal with accutane? Why is it relevant and what’s important to beware of?

Answer 5

• retinoid. basically high dose of vitamin A: decreases inflammation, decreases sebum production, increases normal desquamation
• taken orally, don’t take while pregnant or your baby will be fucked (birth defects)

Question 6

What happens with excess of vitamin A?

Answer 6

• birth defects if pregnant

- death if you eat too much like from polar bear liver: dermatitis, liver toxicity, hemorrhages, red skin

Question 7

What is the process of storing vitamin A (retinol) in the body?

Answer 7

Pre-formed retinol and retinyl esters come from animals, provitamin A, carotenoids (inactive), come from plant sources. Both are converted to retinol in the small intestine and absorbed. Stored using the same mechanism as fat absorption and sent to the liver to be stored as retinyl esters.

Question 8

What are the three active forms of vitamin A found in the body? Which is the most active?

Answer 8

Retinol, retinal, retinoic acid. Retinoic acid.

Question 9

How does lack of vitamin A cause night blindness?

Answer 9

Rhodopsin is a combination of retinal in the body and the protein opsin. Rhodopsin interacts with photons, which then separates opsin from retinal and you need a new retinal molecule. If you don’t have enough retinal in the body, you can’t do this and you get night blindness.

Question 10

What are the different types of carotenoids found in veggies and what have they been found to prevent?

Answer 10

• lycopene (tomatoes and red fruits and veg)
• beta-carotene (apricots, carrots, papaya, spinach, broccoli)
• cryptoxanthin (orange rind, papaya, egg yolk, butter, apples)
• prevent prostate, oral and cervical cancer (the dirty ones…) (but not vit a supplements)

Question 11

Vitamin E name

Answer 11

tocopherol

Question 12

Discovery of Vitamin E (tocopherol)

Answer 12

Katharine Bishop, Herbert McLean Evans. lettuce and wheat germ oil for rats allowed them to reproduce, when with a purified diet w vitamin supplements they couldn’t

Question 13

Absorption, Transport and Storage of Vitamin E:

Answer 13

• Vitamin E encapsulated in micelles absorbed in the small intestine
• enters lymphatic circulation in chylomicrons
• stored in liver
• circulated to tissues in lipoproteins

Question 14

Functions of Vitamin E:

Answer 14

• main function: antioxidant (donates an electron to highly reactive free radical oxygens that have unpaired electrons) (free radicals= oxidative stress)
• stabilize cell membranes (so they aren’t being fucked by free radicals)
• protects tissues from oxidative damage: heart, lungs, DNA, cell membranes, eye, liver, breast, muscle tissues

Question 15

What causes oxidative stress (solved by vitamin E and other antioxidants)?

Answer 15

-environmental factors like UV light, radiation, inflammation, smoking, air pollution

Question 16

How do antioxidants fix oxidative stress?

Answer 16

by donating an electron to highly reactive free radical oxygens that have unpaired electrons. otherwise free radicals will steal electrons from other stable atoms in the body.

Question 17

What is needed for vitamin E to keep working as an antioxidant?

Answer 17

It needs other antioxidants like vitamin C to regenerate its electrons.

Question 18

Vitamin E (tocopherol) causes and effects:

Answer 18

Causes:
-fat malabsorption or rare genetic disorders

Effects:

• breakdown of cell membranes and tissue damage due to oxidative stress
• Myopathy: damage to heart and smooth muscles
• Hemolysis: RBCs burst
• peripheral neuropathy and degeneration of axons: nerve damage

Question 19

What happens with too much Vitamin E (tocopherol)?

Answer 19

• can interfere with blood clotting by increasing the metabolism and excretion of Vitamin K
• inhibits the conversion of Vitamin K to its most active form
• can lead to hemorrhaging

Question 20

Discovery of Vitamin K

Answer 20

1935 Henrik Dam.

• Vitamin K for blood “Koagulation”
• chickens fed on fat-free diet were hemorrhaging
• was fixed by leaves and pigs liver (K1 and K2)

Question 21

What are the types of Vit K and where are they found?

How is dietary Vit K activated?

Answer 21

• K1 in plants, K2 in livers of animals and microbe fermentation
• by being given an extra electron by an antioxidant

Question 22

Absorption, Transport and Storage of Vitamin K:

Answer 22

• absorbed in the small intestines by the same mechanisms as dietary fat
• circulated to tissues in lipoproteins
• stored in adipocytes

Question 23

Functions of Vit K:

Answer 23

-blood clotting

bone health:

• improves osteoblast & inhibits osteoclast function
• needed to synthesize the bone protein osteocalcin
• modifies osteocalcin (makes it negatively charged) to bind calcium ions (positively charged), to make hydroxyapatite (HA) crystals (HA crystals attach to collagen fibers produced by vit C to make bone structure)

Question 24

What is the vitamin k cycle? (k hole?)

Answer 24

When it’s reduced (given an electron), oxidized, and reduced again back to dietary form of vitamin k.

Question 25

What’s the process of blood clotting from vit K?

Answer 25

Vit K helps to make prothrombin, activated to thrombin. Thrombin needed for fibrinogen, activated to fibrin, which helps to blood clot.

Question 26

Causes and effects of Vit K deficiency:

Answer 26

Causes:

• infancy (don’t have a developed microbiome to make vit k)
• too much vitamin E or anti-coagulants

Effects:
-hemorrhaging

Question 27

What happens with too much Vitamin K?

Answer 27

nothin

Question 28

Endogenous and exogenous sources of Vit K?

Answer 28

-diet (kale, collards) and colon microflora (why babies need vit K shots at birth)

Question 29

Discovery of Vitamin D:

Answer 29

Adolf Otto Reinhold Windaus.

• rickets big problem in industrial revolution
• Puppies fed bread or oatmeal with whole milk would develop rickets if kept indoors, but not if taken for outdoor walks.
• found that cod liver oil would prevent the disease even after it had been aerated to destroy vit A
• irradiate rats or their food with UV light could prevent or cure rickets.
• Isolated the precursor in the skin which is converted to Vitamin D3 in response to UV radiation

Question 30

Which vitamins are fat soluble?

Answer 30

Vit A, D, K, E

Question 31

Absorption, Transport and Storage of Vitamin D

Answer 31

Vit D2/3 comes from food. Or sun hits a precursor in skin and it becomes D2/D3. D2/3 converted to inactive calcidiol in liver. Goes to liver and becomes active calcitriol. Then can be absorbed in SI.

Question 32

Functions of Vit D:

Answer 32

• increase blood calcium levels by increasing absorption of calcium in small intestines (in response to parathyroid hormone from parathyroid gland)
• bone density
• needed for DNA transcription and gene expression
• because of this, responsible for cell differentiation (like vitamin A)
• immunity and inflammatory response for same reason (cell differentiation like vitamin A)

Question 33

Causes and effects of vitamin D deficiency:

Answer 33

Causes:

• lack of sunlight and dietary vit D (smog, low sunlight, burkas that cover skin)
• diseases of liver, kidneys or small intestine (b/c it affects calcidiol and calcitriol production and D3 absorption)
• medications
• aging (skin doesn’t respond as well to the sun)
• surprisingly not from low fat diets (that’s more for vit k and e and a)

effects:
- rickets in kiddos
- osteomalacia (bone softening): low calcium levels and low bone density in everyone
- in elderly: osteoporosis and muscle weakness (b/c of gene expression for muscle build up, and b/c muscles also need calcium for contraction). also increased falls b/c of muscles.
- cancer, low immunity/inflammation
- cancer, tuberculosis, the flu, and heart disease (they’re not sure why)

Question 34

What happens with excess of vit D (usually only from supplements)?

Answer 34

• hypercalcemia (too much calcium in bloodstream): loss of appetite, nausea, muscle weakness (need to have the right balance), pain, vomming, neuropsychiatric disturbances, effects on kidney (increased urination, dehydration, thirst, kidney stones, renal failure)
• too much calcium can lead to calcification of soft tissue: especially problematic for the heart valves, which need elasticity for circulation. can lead to arrhythmias and death.

Question 35

If you want to increase your bone density, what supplement(s) do you need to take?

Answer 35

Both vitamin D and calcium. also make sure you have enough vitamin K to make the hydroxyapatite crystals.