Vitamin C
Vitamin C may be found in citrus fruits, tomatoes, leafy green vegetables, and
potatoes and used to metabolize carbohydrates and used for synthesis of protein,
lipids, and collagen. Vitamin C is also required for capillary endothelium and
repair of tissues. Vitamin C aids in the absorption of iron and the metabolism of
folic acid. Unlike fat-soluble vitamins, vitamin C is not stored in the body and
is excreted in urine. However, high serum levels of vitamin C can result from
excessive doses and be excreted without any change. Vitamin C is commercially
available as Ascorbicap, Cecon, Cevalin, Solucap C.(^144) CHAPTER 9 Vitamins and Minerals
Dose for treatment Adult per day is 50 to 100 mg. For severe deficit (scurvy)
of deficiency PO: IM: IV: 150–500 mg/d in 1 to 2 divided doses. 500 to
6000 mg/day for treatment of upper respiratory infections,
cancer, or hypercholesterolemia.
Maintenance 45–60 mg/d
Pregnancy category C
Deficiency conditions Prevents and treats C deficiency (scurvy); increases wound
healing; for burns; sickle cell crisis; deep vein thrombosis;
Megavitamin therapy (massive doses) of vitamins are not
recommended as it can cause toxicity.
Side effects Headaches, fatigue, drowsiness, nausea, heartburn, vomiting,
diarrhea. Vitamin C with aspirin or sulfonamides may
cause crystal formation in the urine (crystalluria); it can
also cause a false-negative occult (blood) stool result and
false-positive sugar result in the urine when tested by the
Clinitest method.
Adverse reactions Kidney stones, crystalluria, hyperuricemia; Massive doses can
cause diarrhea and GI upset.
Contraindications Large doses can decrease the effect of oral anticoagulants;
oral contraceptives can decrease C concentration in the body;
smoking decreases serum levels of C, use with caution in renal
calculi (kidney stones); gout, anemia, sickle cell, sideroblastic,
thalassemia
Drug-lab-food interactions Decrease ascorbic acid uptake taken with salicylates; may
decrease effect of oral anticoagulants; may decrease
elimination of aspirins
Vitamin C