However, not all vitamin C supplements contain the same amount of vitamin C, and the vitamin C in the supplements can come in different forms. The most common forms of vitamin C in supplements are ascorbic acid, calcium ascorbate, sodium ascorbate or a combination of those. Vitamin C is absorbed by the body in the digestive tract and then reabsorbed by the kidneys, so supplements must break down to be utilized by the body. If the ascorbic acid in a supplement does not break down efficiently, the body cannot use it, and it will be excreted. In addition, high doses of ascorbic acid are not likely to be completely absorbed, so it is preferable to take divided doses of the vitamin throughout the day instead of a single large dose.
how much do I need?
The recommended daily allowance (RDA) of vitamin C was increased in April 2000 by the Institute of Medicine. The RDA is set now at 90 mg/d for men and 75 mg/d for women, adding an additional 35 mg/d for smokers. The Tolerable Upper Intake Level was set at 2 g/d. Good sources of vitamin C are citrus fruits, broccoli, Brussels sprouts, cabbage, green peppers, potatoes, spinach, strawberries, sweet peppers, hot peppers and tomatoes. Overdoses of vitamin C can lead to headaches, stomach cramps, nausea, vomiting, diarrhea and kidney stones. In rare cases, taking high amounts of vitamin C during pregnancy and abruptly withdrawing from supplementation can lead to rebound scurvy in both the mother and the baby. People with blood disorders or problems with kidney stones should avoid high doses of vitamin C.
Provided courtesy of HSR
