Micronutrients Vitamin C Flashcards
What is vitamin C also known as?
Ascorbic Acid
How many canadians take a vitamin C supplement?
1/3
Smokers require an extra amount of vitamin C? Why?
Yes, 35 mg/day extra because they under oxidative stress by smoking
what are the 2 physiological functions of vit C?
- Acts as a coenzyme
- Acts as an anti-oxidant
How does vitamin C act as a coenzyme?
Involved in collagen synthesis (helps with would healing), carnitine production, and neurotransmitter (noradrenaline) formation
How does Vit. C act as a an anti-oxidant?
– Defends against free-radicals (or neutralizes free radicals)
– Protects tissues from oxidative damage, so may help
prevent diseases
– Regenerates other antioxidants within the body (e.g.
Vitamin E)
How common is severe defiency, scurvy of Vit.C?
Uncommon
How do you get scurvy?
Need vit. C intake to be <10 mg for many weeks
What percentage of 20-29 year olds do NOT get adequate intake?
50%
Who else is vit.C deficiency found in?
Found in elderly, people with substance use disorders, smokers, and others with a poor diet
What are the toxicities and effects of vitamin c?
- Generally well tolerated
- Higher doses (>2g/d) can lead to diarrhea and GI upset
What is the evidence on prevention of cancer?
Evidence is inconsistent on whether it affects cancer risk
What is the evidence for the treatment of cancer?
- Large oral doses (up to 10g/d) have shown no benefit in the treatment of advanced cancer
- Some studies support the use of high-dose IV vitamin C (able to raise plasma level >1000x that of oral dose)
What is the relationship between the intake of fruits/vegetables and cancer incidence?
Inverse
What is the evidence for the use of vitamin C for the prevention of common cold?
(up to 2 g/d) does not decrease # of colds in average
person (higher dose trials included)
* May provide some benefit in people under physical
stress – not under normal conditions
