Vitamin C Flashcards
What are the functions of Vitamin C?
Collagen Formation
Prevention of anemia
Antioxidant
BitCh CortH Trying to be DouBly NorDic. May Leu just be a Phagocyte?
Synthesis of Bile acids from Cholesterol
Hydroxylation reactions in the formation of corticosteroid hormones
Conversion of Tryptophan to Serotonin
Dopamine beta hydroxylase participates in the biosynthesis of norepinephrine from dopamine
Metabolism of tyrosine
Required for normal leukocyte function
Stimulates phagocytic functions of the RE system thereby boosting immunity
Describe the role of Vitamin C in collagen formation
Post translational hydroxylation of Lysine and Proline residues in collagen
Normal collagen formation is necessary for connective tissue maintenance, wound healing, formation of normal blood capillaries, cartilage and bone formation.
Also has a role in Osteoid formation (in bones)
Describe the role of Vitamin C in preventing anemia
Maintains metal cofactors in their lower valence state, e.g. Fe+2 and Cu+ - therefore increases iron absorption by reducing the ferric to ferrous in the stomach
Reconversion of Methemoglobin to hemoglobin
Synthesis of Tetrahydrofolate from Folic acid (required for cell division)
Describe how Vitamin C acts as an antioxidant
Scavenges reactive oxygen species (ROS)
Protects compounds from oxidation by donating electrons
What are some potential effects of oxidative damage by ROS?
DNA, unsaturated fatty acids, and proteins are particularly prone to oxidative damage by ROS
Atherosclerosis and cancer are also related to oxidative damage
Which groups of people are susceptible to Vitamin C deficiency?
Seen in breast-fed infants who don’t receive food supplements rich in Vitamin C (milk is poor in Vitamin C)
Increased requirement in smokers (100 mg/day)
Increased requirement in pregnant/lactating women
Increased requirement in convalescing people
Increased requirement during wound healing
What is the RDA of Vitamin C?
60 mg/day
What are signs and symptoms of Vitamin C deficiency?
Easy bruising & Petechiae (pinpoint hemorrhages in the skin) due to increased capillary fragility
Severe deficiency causes scurvy
What are the signs and symptoms of scurvy?
GUT HEALTH FROST THINE HEART
Bleeding gums
Loose teeth
Hemorrhages & anemia
Poor wound healing
Osteoporosis & easy bone fractures (abnormal osteoid formation)
Hemorrhage may occur in conjunctive and retina.
Internal bleeding - Nose bleed, hematuria and malena
Bleeding is a common sign of Vitamin C deficiency because the collagen formation is abnormal, leading to capillaries bursting under minor pressure
What are some food sources fo Vitamin C?
Citrus fruits (lime and orange), strawberries, bell peppers and green leafy vegetables
How may Vitamin C be destroyed?
Vitamin C is unstable (labile) and can be destroyed by heat, oxygen and light
Supplementing Vitamin C
Contain high doses of Vitamin C
May act as antioxidant, boost immune function, prevent atherosclerosis and cancer
Not fully tested and may have long-term adverse effects
