Vitamin C ascorbic acid
Water soluble
least stable of all vitamins
easily oxidised
Functions
protects body against infections and bacterial toxins
promotes
involved in metabolic reactions with amino acids and folate/folacin
involved in secretions of certain hormones, e.g. thyroxin and adrenaline
helps maintain elasticity and strength of blood vessels
formation of bone matrix and tooth dentine
conserving effect on vitamins A, B, and E
formation and maintenance of collagen
collage is a protein that is important component of intracellular material
absorption of non-heme iron
deposition of iron in the liver
formation of haemoglobin
Sources
potato a good source
other sources
best source: citrus fruit
level of vit C very dependent on how food is handled
fruit and veg principle source
often added to foods, particularly fruit drinks and juices
e.g grapefruits, orange, naartjie, etc
brussel sprouts
cauliflower
broccoli
cabbage
strawberries
spinach
Special requirements
additional vit C required for
tissue healing of wounds
fever and infection
certain drugs
growth
stress
smokers suffer from increased oxidative stress and metabolic turnover of Vit C
Deficiency
scurvy can occur in infants whose only source of food in cow's milk
symptoms
scurvy results from prolonged deficiency
treatment
rare in developed countries
can occur in people with low veg and fruit intake and those that abuse alcohol
breast milk usually contains sufficient vit C to prevent scurvy
haemorrhages of the skin and mucous membrane
anaemia
inflamed and bleeding gums
impaired wound healing
weakness
fatigue
depression
patient should respond to Vit C treatment within days
dietary deficiencies need to be corrected
diet should include as much fresh fruit and veg as possible
Excess
excess expelled in urine therefore toxic effects are rare
if very large amounts are consumed toxic effects may occur
sypmptoms
stomach cramps
gastrointestinal disturbances
diarrhoea