Vitamins-Fat Soluble Flashcards
What is a vitamin
An essential, non-caloric, organic nutrients needed in tiny amounts in the diet.
Which vitamins are fat soluble?
A, D, E, K
Which vitamins are water soluble?
B and C
What does it mean for a vitamin to be fat soluble
- It dissolves in lipids (fat)
- Requires bile for absorption
- Are stored in tissues
- Potentially toxic
Primary Function of Vitamin A
Vision (hormonal, and functional), Hormone-like
Main sources of Vitamin A
Animal (eg liver)
Plant (carotenoids)
What’s the major vitamin A deficiency result
Night Blindness
Xeropthalmia (eyes drying out)
Is too much vitamin A toxic?
YES! Fetus malformations, Hair loss, Joint pain, etc.
Are there any notable digestion/absorption issues with vitamin A?
Nope!
Vitamin A Interesting metabolism
Beta-carotene conversion, and beta-carotene is not toxic!
Who’s primarily affected by vitamin A problems?
Children in developing countries
Where is vitamin A stored?
Liver
What is a naturally occurring precursor of Vitamin A?
Beta-Carotene!
Advantageous because it’s not stored in the liver, so it’s not toxic if consumed in excess. Also has an inefficient conversion to active vitamin A.
Primary functions of Vitamin D
Calcium regulation; Hormone like functions
Main sources of vitamin D
Sunlight to activate cholesterol!
Fish, fortified foods, FEW foods.
What’re the main symptoms of vitamin D deficiency
Ricketts, Osteomalacia
Is vitamin D toxic?
Rarely
Are there any notable digestion/absorption issues with Vitamin D
NONE
What’s the interesting metabolism with Vitamin D?
Sunlight-cholesterol-liver-kidney mechanism
What’s the current public health controversy with vitamin D
Allow some sun, but not too much for skin cancer, but then if we’re taking supplements how much of that?
Where are the 3 main places vitamin D has it’s effect?
- Intestine (regulate calcium absorption)
- Bone (regulate amount breaking down and building up)
- Kidney (ability to be more or less efficient in reabsorbing calcium)
What’s the primary function of Vitamin E?
Antioxidant
What’s the main source of Vitamin E?
Plant oils/fats
Are people ever vitamin E deficient?
No.
Are people ever plagued with vitamin E toxicity?
No.
Are there any notable digestion/absorption issues with Vitamin E?
Nope!
Are there any interesting metabolism tricks with vitamin E?
No
Which population subgroups are affected by Vitamin D?
Children in developing countries, soda drinkers, elderly with low sun exposure, populations above or below certain latitudes, dark skin.
Why has Vitamin E been a huge disappointment?
Despite high enthusiasm for protection from heart disease and cancer, clinical trials WITH dietary supplements at high doses have demonstrated few/negligible benefits, and some adverse effects.
Among what age group does the classic Vitamin E deficiency symptom occur?
Premature Babies
What’s the primary function of Vitamin K?
Blood clotting, bone protein
What’s the main source of Vitamin K?
Dark green leafy vegetables, intestinal bacteria
Is deficiency of Vitamin K common?
Nope! Pretty rare.
Is Vitamin K toxicity common?
Nope! Pretty rare.
Are there any notable digestion or absorption issues with vitamin K?
Nope.
What’s the interesting Vitamin K metabolism mechanism?
Can interfere with warfarin therapy (warfarin is a blood thinning drug)
What population subgroups are impacted by Vitamin K?
Infants; Adults taking warfarin.
Why are newborn infants injected with vitamin K?
Because they don’t yet have extensive gut micro flora, and they still need to have their blood clot.
Who might take too much vitamin K?
Individuals on the medication warfarin that are also ingesting a lot of vitamin K, people with heart problems.
Vitamin A toxicities
Birth defects with 13-cis retinoic acid; over-stimulated cell division!
Do all fat-soluble vitamins decrease with low fat?
YES.
What did cohort studies find out about vitamin E supplementation
Higher quintiles of consumption were associated with lower coronary disease
Interventional cell study with vitamin E
Establish biological mechanism (as an antioxidant)
Did the randomized control trial find that vitamin E works?
No
What is the relationship between the function of Vitamin E, fats, and food sources?
Vitamin E functions as an antioxidant, particularly for your unsaturated fats, many PUFAs in plants, also come with vitamin E already.
Widespread availability in foods.
