Vitamin C (Ascorbic Acid)
Requirements:
- RDA:
60 mg./day saturates RBCs but not the serum
400 mg./day-serum level is >1.4 mg./dl. - note: vitamin C in
adrenals is 50x that of serum
>400 mg./day- increased tissue levels of vitamin C
- Daily Optimal Intake:
Supplement Forms:
- Calcium ascorbate - buffered form of vitamin C
- Chewable vitamin C - not recommended since it usually contains
sugar and may cause the pH of saliva to be so low to cause
leaching of calcium from tooth enamel
- Ester C - very expensive but can be tolerated better by those
who experience gastrointestinal side effects from other forms of
vitamin C
- Natural, inexpensive vitamin C is usually synthesized from
starch, molasses or sago palm
- "Rose hips" - the plant contains only 1% vitamin C, so most of
the vitamin C in rose hips products is synthetic in origin (other
constituents in rose hips may prove valuable)
Labs:
- Test:
Leukocyte: 30 ug./108 WBCs
Load Test: 0.3 - 2.0 mg./hr. in control; 24 - 49 mg./hr. after
500 mg.
Serum: >0.3 mg./dl.
Food Sources:
- Broccoli, raw, chopped 1/2 cup (41 mg.)
- Brussels sprouts, raw 4 (65 mg.)
- Cantaloupe 1/4 (56 mg.)
- Green peppers, raw, chopped 1/2 cup (64 mg.)
- Grapefruit 1/2 (39 mg.)
- Grapefruit juice, fresh 1 cup (94 mg.)
- Guava 1/2 (83 mg.)
- Kiwi fruit 1 med .(75 mg.)
- Orange 1 (70 mg.)
- Orange juice, freshly squeezed 1 cup (124 mg.)
- Papaya 1/4 med. (94 mg.)
- Strawberries 1/2 cup (42 mg.)
- Tomato juice 1 cup (45 mg.)
- Watermelon 1/16 (47 mg.)
Signs and Symptoms of Deficiency:
- Aching bones, joints, and muscles
- Anorexia
- Dry skin
- Fatigue
- Gums deep blue-red color
- Hemorrhage
- Follicular hyperkeratosis
- Listlessness
- Loose teeth
- Muscle cramps
- Secondary infections
- Shortness of breath
- Sore and bleeding gums
- Weakness
Causes of Deficiency:
Adverse Effects and Toxicity:
- Affects testing for serum cholesterol
- False negative test for glucose in urine
- False negative test for occult blood in urine
- Glucose-6-phosphate dehydrogenase deficiency patients may
suffer hemolysis with intravenous vitamin C (although other
factors may also be involved)
- Increased absorption of iron
- Intestinal gas and diarrhea in large doses (>3 grams)
- Some stool tests for occult blood may be affected by large
doses of vitamin C
Drug/Nutrient Interactions:
- Aspirin and tobacco smoke deplete vitamin C
- Adriamycin cardiotoxicity is lessened with vitamin C
- Indomethacin decreases absorption of vitamin C
- Phenothiazines and vitamin C may work synergistically for neuroleptic associated with amenorrhea
- Decreases therapeutic effect of warfarin
- Oral contraceptives decreases plasma levels of vitamin C
Biochemical Functions:
- Active role in converting folacin to tetrahydrofolic acid
- Active role in converting tryptophan to 5-hydroxytryptophan to
serotonin
- Antibacterial
- Antihistamine
- Antiviral
- Carnitine synthesis
- Collagen synthesis
- Decreases sorbitol levels in RBCs
- Degradation of cholesterol
- Drug metabolism
- Norepinephrine synthesis
- Promotes urinary excretion of uric acid
- Reduces ferric iron to ferrous iron
- Regulation of cellular humoral immune function
- Steroid hormone synthesis
Clinical Indications:
Copyright 1998 - 2008 by L. Vicky Crouse, ND and James S. Reiley, ND. All rights reserved (ISSN 1527-0661).