Vitamins Flashcards
What is the most abundant ion in chyme?
Na+
Where is Fe absorbed?
At the duodenum
Where are vitamins B & C absorbed?
And how?
At the Jejunum
Diffusion or mediated transport
What is absorbed at the ileum?
Vitamins A,D,E,K and B-12
What are the 2 types of vitamins?
Fat soluble
Water soluble
Which vitamins are fat soluble?
A,D,E,K
Which vitamins are water soluble?
B & C
What is vitamin B-12?
A very large and charged vitamin
How is B-12 absorbed?
B-12 binds to R protein, transcolbalamin - 1 in stomach
Cleaved at duodenum + binds to protein intrinsic factor (secreted by parietal cells of the stomach)
Then binds to specific sites on the epithelial cells in the lower portion of the ileum (terminal ileum) where it is absorbed via endocytosis
What is vit B-12 needed for?
And a deficiency in this can lead to?
Erythrocyte formation
Can lead to pernicious anaemia and is usually caused due to a deficiency in intrinsic factor
Vitamin A What is it referred to as? Function? Sources? Deficiency? Stored in?
‘rhodopsin’, ‘caretonoids’, ‘RETINOL’
VISION (retinal pigments), cellular growth and differentiation, reproduction, embryonic development
CARROTS, liver, dairy, oily fish, margarine
Night blindness
Absorbed as a lipid, stored in liver, ito cells in the space of Disse
Vitamin D What is it referred to as? Function? Sources? Deficiency? Stored in?
‘Calciferol’
Ca2+ & phosphate intestinal absorption
UV light from sun (activates cholecalciferol)
Bone issues (osteomalacia- weak bones) (rickets)
Stored in liver (inactive form), converted to active form in kidney
Vitamin D is considered more of a …… as….
Hormone
Already exists in the body-needs to be activated
Where is vitamin D2 & 3 derived from?
D2 - plants
D3 - UV from sun
Liver storage of vitamin D prevents deficiency for how long?
3-4 months
Vitamin E
Function?
Found in?
Stored in?
Anti oxidant (anti aging)
Nuts and seeds
Liver
Vitamin K
Function?
Found in?
Deficiency?
Activates clotting factors 10,9,7,2 in liver
Plants, food, synthetic K3 & 4
Bleeding disorders
Which drug is an anticoagulant and what does it do to vitamin K?
Warfarin
Inhibits vitamin K
Vitamin B-12 Function? Found in? Deficiency? How is it absorbed?
Cell metabolism & energy production
Fish, poultry, meat,eggs
Results in less erythrocyte formation - pernicious anaemia
Absorbed as B-12 intrinsic factor complex
Vitamin C
Function?
Sources?
Deficiency?
Immune system, Fe absorption, antioxidant
Synthesis of collagen, neurotransmitters & carnitine
Fresh fruit and veg
Scurvy
What is Fe digested as…. and transferred into blood as…..
Fe is stored in the ……. As ……
Digested as normal form & transferred into blood as transferin
Stored in liver as ferritin
Cu is stored in?
Liver
Where is Ca2+ from?
What is it needed for?
From dairy
Needed for muscle contraction + synaptic transmission
What is iodine part of?
What foods is it found in?
Thyroid hormone
Sea food
Malabsorption of vitamins and minerals results in ….
Malnutrition
What is malabsorption?
The inadequate absorption of nutrients from the intestines
What are 3 diseases that cause malnutrition?
Coeliac disease
Giardiasis
Cystic fibrosis
What is coeliac disease? How does it cause malnutrition?
A disease in which the small intestine is hypersensitive to gluten, leading to gluten intolerance
Decreased SA of brush border
What is giardiasis? How does it cause malnutrition?
Infection that causes the villi to atrophy (erode away) thus reducing absorption capacity
What is cystic fibrosis?
How does it cause malnutrition?
An autosomal recessive mutation
Impaired Cl- out therefore mucus build up on GI tract
What is the equation for BMI?
BMI=weight(kg)/height(m^2)
What does it mean if
BMI>30
>25
<18.5
Obese
Overweight
Underweight
What is the range of a normal BMI?
18.5
What is the definition of the BMR?
Basal metabolic rate
Minimum amount of energy required to keep the body alive
What is the equation for BMR?
BMR = kcal/hr/m^2
When does BMR decrease?
With age
