Topic 7: Water Soluble & Fat-soluble Vitamins Flashcards
(15 cards)
What is the general role of vitamins in the body?
They act as coenzymes in:
- energy metabolism
- DNA synthesis
- neurological function
- blood clotting
- antioxidant activity, and
- tissue synthesis.
Are vitamins organic or inorganic compounds?
Vitamins are organic compounds, unlike minerals which are inorganic.
What factors influence vitamin bioavailability?
- Digestion
- nutrient interactions
- previous nutritional status
- food preparation, and
- whether the source is synthetic, fortified, or natural.
Which vitamins are fat-soluble?
Vitamins A, D, E, and K.
Which vitamins are water-soluble?
B-group vitamins and vitamin C.
Where are fat-soluble vitamins stored in the body?
In the liver and adipose tissue.
How are water-soluble vitamins excreted?
They are excreted in urine and require frequent intake.
How are fat-soluble vitamins absorbed?
Absorbed into lymph via micelles and chylomicrons, requiring dietary fat.
How are water-soluble vitamins absorbed?
Absorbed directly into the bloodstream and circulate freely.
What is a vitamin precursor (provitamin)?
A substance that must be converted into the active form of the vitamin in the body.
Give an example of a vitamin and its precursor.
Beta-carotene is a precursor to retinol (vitamin A); 7-dehydrocholesterol is a precursor to vitamin D3.
What are deficiency symptoms of vitamin B12?
-Macrocytic anaemia
-nerve damage
-fatigue, and
-cognitive decline.
What are risk factors for vitamin D deficiency?
- Limited sun exposure
- darker skin
- ageing
- obesity, and
- certain medical conditions.
Why must vitamin K intake be consistent for people on warfarin?
Warfarin interferes with vitamin K’s role in clotting. Inconsistent intake affects drug efficacy and clotting times.
What is unique about biotin among B vitamins?
Biotin:
- functions as a coenzyme in carboxylation reactions,
- supports gluconeogenesis and fatty acid synthesis, and
- can be synthesized by gut bacteria.
