Vitamins Flashcards
Which vitamin is most likely to give you toxicity symptoms
vitamin A
Bioavaliability
the degree to which nutrients can be absorbed and utilized by the body
3 things that can influence bioavaliablity
- present/absence of chronic diseases 2. age 3. alcohol abuse
How can our bodies synthesize and activate vitamin D
cholesterol + UV radiation = vitamin D liver and kidney enzymes activate it.
What is the predominant form of vitamin D found in our food
D2 Ergocalciferol
What happens to 80% of ingested vitamin D
incorporated into micelles
1 cause of non-traumatic blindness worldwide?
Vitamin A deficiency
Distinguish between Retinoids and Carotenoids
Retinoids are the most significant form in our diet and are called pre formed vitamin A because they are already active. Carotenoids have to be converted to Retinoids to be active.
Explain vitamin A absorbtion
- retinyl esters are converted to retinol in SI
- once absorbed, retinol re forms retinyl esters
- retinyl esters are packed into chylomicrons and sent to liver
- liver mobilizes stored vitamin a as retinol + retinol binding protein + transthyretin
- complex binds with retinol binding protein receptors on target cells
- endocytocisis and package with cellular transport protein
- complex binds with RAR/RXR nuclear receptors
- complex interacts with DNA to influence gene expression
3 sx of vitamin A deficiency
- blindness 2. night blindness 3. dry skin
3 sx of vitamin A toxicity
- GI issues 2. visual issues 3. HA
2 functions of vitamin E
- antioxidant 2. cell membrane integrity
2 sx of vitamin E deficiency
- anemia 2. nervous sx damange
2 functions of vitamin k
- coagulation via prothrombin 2. osteocalcin formation
What is the only water soluble vitamin that isn’t a coenzyme
choline
B1
Thiamin
