Vitamin C Flashcards Preview

Micronutrients > Vitamin C > Flashcards

Flashcards in Vitamin C Deck (12)
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1

Function

Antioxidant (reducing agent).

Reduces mineral cofactors: norepinephrine synthesis, collagen synthesis, etc.

Reverses oxidation. Electron donator.

2

CVD

Inhibits LDL oxidation which diminishes plaque formation.

3

Interaction with iron

Enhances absorption of non heme iron.

Keeps iron reduced in collagen and carnitine synthesis.

4

Excretion

Urine as ascorbic or dehydroascorbic acid.

Oxidation to dehydroascorbic acid occurs in liver.

5

RDA

90 mg men
75 mg women

6

Deficiency

Scurvy.

7

Toxicity

2g
Abdominal pain and osmotic diarrhea due to unabsorbed vitamin C in the GI.

Risk of kidney stones in renal PT and iron toxicity in individuals with iron metabolism problems.

8

Assessment

Leukocytes reflect body stores.
Serum.

9

Sources

Red peppers and papaya. OJ.

100% absorption at intake

10

Transporters

Transported through blood in free form.

Ascorbic acid: sodium dependent transporter (SVCT1 and SVCT2)

Dehydroascorbic acid: oxidized in GI then transported via glucose transporters (GLUT1 and GLUT3). Competes with glucose.

11

Glutathione (GSH)

Reduces DHA back to ascorbic acid.
Spares vitamin C.

Recycles.
Uses niacin.

12

Gulonolactone oxidase

Last enzyme in vitamin C synthetic pathway. Polymorphism.