38543716
Description
Flashcards by Jennifer Cloward, updated more than 1 year ago
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Created by Jennifer Cloward
almost 2 years ago
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| Question | Answer |
| Foods high in Vit C | Rose hip, sea buckthorn (400), red pepper (128), papaya (61), kiwi (93 mg), melon, spinach, celery, guava (228 mg), cauliflower (48), cabbage (36), pineapple, Brussels sprouts, orange (53 mg), broccoli (89 mg) |
| When was Vit C discovered? | Isolated in 1927 and determined in 1933. |
| Brief hx of Vit C | During a British voyage in the 1740’s, there were 1300 of 2000 men that died. In 1747, James Lind experimented (HMS Salisbury) & took 12 men splitting them into 6 dietary interventions. Those that ate oranges were cured. It took 40 years after this before the British fleet added citrus fruits to rations. |
| What enzyme do humans lack to synthesize Vit C? | L-gulonolactone oxidase (the last enzyme in the Vit C synthetic pathway). |
| Briefly, the pathway from glucose to Vit C | D-glucose —> D-glucuronate —> L-gluconate —> L-gulonolactone —> 2-keto-gulonolactone —> ascorbic acid |
| What is the main source of Vit C in foods? | L-ascorbic acid |
| What form is Vit C mostly present at in the human body? | Ascorbate, about 5% is available as dehydroascorbic acid (which can be converted back to ascorbate). |
| What is the ‘sacrifice system’? | Glutathione donates 2 H and 2 E- to make up for the lost ones, converting back to ascorbate. |
| Where is Vit C mostly absorbed? | In the small intestinal wall of the jejunum. About 70-95% of Vit C is absorbed at moderate intakes of 30-180 mg/day. If over 1g/day, then less than 50% is absorbed and it is excreted. |
| What is the RDA for VitC? | 75 mg/day male 90 mg/day female 100 mg/day pregnant 120 mg/day breastfeeding |
| More metabolically active tissue require ___ Vit C | More |
| Briefly describe absorption of Vit C | |
| Which transporters aid in Vit c absorption? | |
| What are the fx of Vit C? | (1) CVD (2) Anti-oxidant (3) Immune fx (4) Collagen synthesis (5) Iron absorption |
| Mechanisms of action for the functions of Vit C | |
| Explain hydroxylation of Vit C during collagen synthesis | |
| Explain Vit C pathway in neurotransmitters | |
| Explain Vit C pathway as an anti-oxidant | |
| Vit C aids in ___ absorption | Iron, especially non-heme |
| Deficiency of Vit C results in | Scurvy |
| The 4 H’s | How to remember scurvy Hemorrhagic Hyperkeratosis Hypochondriasis Hematologic |
| Too much Vit C is at… | 2 g. Results in osmotic diarrhea and/or GI distress, increased risk of kidney stones for those w/ renal dysfunction, and Fe toxicity for those with Fe metabolism disorders. |
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