Fat soluble vitamins Flashcards
Which molecules are very water soluble?
- COOH
- C-Cl
Which molecules are moderately water soluble?
-COH
Which molecules are not water soluble (fat soluble)?
-CH2-CH2-CH3
What are the fat soluble vitamins?
K, A, D, E
What are the water soluble vitamins?
all the others - especially B group & C
Which vitamins can herbivores not produce?
A & E (fat soluble)
Which vitamins can most animals produce?
C & D (vit D needs sunlight)
Which vitamins can microbes produce?
B group & K
In which conditions may vitamin supplements be needed?
- When on antibiotics
- high grain diets or drought (Vit A & E)
- poor quality diets
- animals in poor sunlight (vit D)
- stress or infection
- nervous or hyperactive
- reduced appetite
- anaemia
How should vitamins be stored?
cool & dry to maintain potency
Vitamin A (retinol) functions/roles…?
- Required for vision -> initiates impulse transmission along optic nerve
- formation & protection of epithelial tissue & mucous membrane
- free radical scavenger (antioxidant)
Deficiency symptoms of vitamin A…? Include sub-clinical deficiency symptoms
Excess lacrimation (tearing) night blindness (lack of rhodopsin synthesis in dark reaction) sub-clinical - rough hair coat, reduced immune response, infertility
Sources of vitamin A…?
green leaves (4-6 weeks grazing green forage provide enough stores (liver) for 3-6 months)
corn
grains (poor)
decreases in cutting & storage
Excess/toxicity of vitamin A…?
fragile bones
dull hair
Vitamin D functions/roles…?
calcium metabolism (uptake from gut & deposition in bone) can be synthesised in skin (UV)
Deficiency symptoms of vitamin D…? Which animals most likely affected?
pet reptiles (animals housed indoors/behind glass as UV does not pass thru glass or plastic) metabolic bone disease (MBD) -> Ca-deficiency -> scoliosis
Vitamin K functions/roles…?
required for synthesis of prothrombin - BLOOD CLOTTING (inactive precursor of thrombin - converts fibrinogen -> fibrin)
Deficiency of vitamin K…?
-> decrease prothrombin & carboxyglutamic acid (needed for Ca binding)
deficiency occurs a few weeks after vit. K not available
causes internal haemorrhage, bruising, poor blood clotting, malformation of dev. bones
What else can cause vitamin K symptoms?
accidental ingestion of rodenticides, anticoagulants, coccidiostats (antiprotozoal agents) which contain vit. K antag’s.
‘sweet clover disease’
Sources of vitamin K…?
Green, leafy material - good source
microbes -> synthesise enough to meet requirements in ruminants
Some conditions in birds deficient in vitamin K?
spontaneous subcutaneous haemorrhage
perifollicular petechiae of the skin (due to frail capillary walls)
Vitamin E storage & functions (many)…?
Stored in liver (dietary fat is needed for absorption of vit E from GIT)
(8 different isoforms)
ANTIOXIDANT (ESP FOR FAT METABOLISM)
IMMUNE FUNCTION
aids in RBC formation & use of vit K
replete endothelial cells of blood vessels -> resist platelets adhesion (prevent ‘false-alarm’ clotting in capillaries)
cell signalling (regulate gene expression)
neuro function
How do vitamins E and C work together as antioxidants?
Fat metabolism (oxidation) in cell membrane -> free radical + active electron. Vit. E ‘mops’ up the electron. Vit. C comes along, accepts the electron and passes it onto electron carrier (NADH) while vit. C returns to its active form
What are the 3 likely situations for Vitamin E deficiency…?
usually caused by poor uptake rather than inadequate diet
- premature, very low birth weight animals
- animals which cannot absorb dietary fat
- animals with rare genetic disorders of fat metabolism
What are the symptoms of vitamin E deficiency…?
- reduced immune response
- neuromuscular probs - spinocerebellar ataxia (intention tremor)
- anaemia due to oxidative damage to RBC’s
What are the implications of high doses of vitamin E?
can be fatal as it is FAT soluble so more difficult to excrete excess
Good natural sources of vitamin E…?
Wheat grain
most seed oils (wheatgerm, sunflower, safflower, canola oils
When would one supplement vitamin E?
in premature, very low birth weight animals
animals on low-fat diets
