Lecture 20 Flashcards
What Vitamins are water soluble?
B vitamins and Vit C
What Vitamins are fat soluble?
A,D,E,K
Are water soluble vitamins stored?
No
Describe recommended intake of water/fat soluble vitamins
- Water = 1-3 days
- Fat = weeks/months
What is the main role of the B vitamins?
Energy metabolism = turning macronutrients into energy to sustain life
What is the role of Thiamin (B1)? How are NZ’s levels? Where does intake come from?
- Nerve processes and energy metabolism
- Levels are good
- Comes from bread and cereals due to fortification
What is the role of Riboflavin (B2)? How are NZ’s levels? Where does intake come from?
- Energy metabolism
- Levels are good
- Top source is milk
What are the symptoms of Riboflavin (B2) deficiency?
- Inflamed eye lids
- Sore throat
- Crack/redness at mouth corners
- Painful/smooth/purplish tongue
- Symptoms are very generalised and could be cause by many different things
What is the role of Niacin (B3)? How are NZ’s levels? Where does intake come from?
- Energy metabolism
- Levels are high
- Mainly comes from poultry and bread
How is B3 measured?
In Niacin Equivalents
-> 60mg of Tryptophan = 1mg Niacin
What is the condition associated with B3 deficiency?
- Pelegra
- Common in 1900’s Southern Diet (low protein/corn based)
What are the symptoms of Pellegra?
The 4 D’s
- Diarrhoea
- Dermatitis
- Dementia
- Death
- Rash when exposed to sunlight
What is the role of Pantothenic Acid (B4)? How are NZ’s levels? Where does intake come from?
- Energy metabolism
- > key part of coenzyme A
- > required for red blood cell synthesis, neuron activity, and antibody production
- Wide spread in food (meats, whole-grains, vege)
- Levels are good, deficiency and toxicity both rare
What is the role of Pyridoxine (B6)? How are NZ’s levels? Where does intake come from?
- Energy metabolism
- Levels are good
- Mainly from fruit and vege
What is the role of Biotin (B7)? How are NZ’s levels? Where does intake come from?
- Part of coenzyme
- > assists in glycogen synthesis and amino acid metabolism
- Widespread in food
- Can be synthesised by intestinal bacteria
- Deficiency and toxicity are rare
What B Vitamin is recommended as supplements during pregnancy and why?
- Folate
- Reduce Neural Tube Defects
Where does Cobalamin (B12) come from?
- Animal products
- Meat, fish, eggs, milk
- Fortified plant milks, marmite, multivitamin
How long is our body’s store of B12?
3-5 years
What are the symptoms of Vit C deficiency?
-Weakness, bleeding gums, loss of teeth, foul breath, painful legs, generalised haemorrhages
What are the two forms of Vitamin C?
- L-ascorbic acid = reduced form (main form)
2. L-dehydroascorbic acid = oxidised form (less common)
How is Vit C synthesised? Can we do this?
- From glucose
- We cannot do this as L-gulonolactone oxidase is missing which blocks the pathway therefore must be obtained from the diet
What can most symptoms of scurvy be derived from?
A loss of collagen
What is the role of Vit C?
- Cofactor for 8 mammalian enzymes
- Antioxidant nutrient
How is NZ’s intake of Vit C?
Much higher than the RDI
-Rich sources come from fruit and vege
Efficiency of Vit C absorption is proportional to what?
Intake
Describe the effect of Vit C and preventing colds
- Won’t prevent it
- Only had an effect for people in extreme cold temperatures or extreme physical strain
Describe the effect of Vit C and cold duration
Regular Vit C intake may shorten length of cold
Describe Vit C Toxicity
- High doses are fine
- More than 2000mg daily may cause
- > Diarrhoea
- > Rebound scurvy
- > Stomach inflammation
