Vitamin C may be the most familiar vitamin on the market. It has a long-standing reputation for immune support; you probably think of vitamin C every time you get a cold. Vitamin C is also a powerful antioxidant, assisting your body to repair the harmful effects of time and toxins. For some people, vitamin C can be used to relieve minor constipation. Interestingly enough, this is a beneficial byproduct of one of the vitamin's few side effects.
Vitamin C Increases Gastric Motility
When given as a supplement at high doses, vitamin C has a laxative effect. This is because the vitamin increases gastric motility, which is to say that it speeds up the digestive process. Most people think of this as a negative side effect, and the vitamin is dosed "to bowel tolerance" -- a discreet way of saying you should reduce your dose if you develop diarrhea.
Benefit of Increased Gastric Motility
The laxative effect of a high dose of vitamin C can be useful for someone with constipation. In this case, a dose would be chosen that increases the frequency of bowel movements. The dose would purposefully exceed bowel tolerance. Once the constipation has eased, the dose of vitamin C can be lowered as well.
Dosing Vitamin C
Recommended dosages for vitamin C vary between sources. In 2000 the recommended daily allowance was revised upwards to 75 to 90 mg daily for most adults. This dose is enough to prevent the deficiency disease scurvy in a nonsmoking adult. Depending on the condition being treated, recommended therapeutic doses of vitamin C range from 450 to 6,000 mg and up.
Vitamin C for Constipation
Most people will reach bowel tolerance between 2,000 and 4,000 mg. This level is thought to increase when the need for vitamin C is greater. That is, if you are fighting off a cold, it may take a higher dose to create an effect on your digestion. For instance, if you normally notice increased gastric motility at 2,500 mg, during your cold you may take 4,000 mg before noticing any change in bowel movements.
Warnings and Contraindications for Vitamin C
Vitamin C is considered a safe supplement for most people. If you are or could become pregnant, it is best not to exceed 6,000 mg vitamin C daily. Levels above this could interfere with pregnancy. Some people may develop kidney stones on high doses of vitamin C. Consult your doctor before taking this or any supplement. Finally, constipation can be a sign of a serious illness and should be evaluated by a doctor before treatment.