Vitamin C is a water-soluble vitamin, which means it is not stored in your body. Any excess you consume through diet or supplements is excreted through urine. While your body works hard to eliminate any vitamin C that is not needed, it can cause gastrointestinal distress in the process. If you take a vitamin C supplement, let your physician know to make sure it doesn't interact with any of your medications.
Vitamin C Benefits
Vitamin C is known for its ability to help your immune system fight off foreign bacteria, keeping you healthy, but it also has other benefits. It acts like an antioxidant by warding off free radicals that permanently damage cells. You need vitamin C to help make collagen, a component of skin, connective tissues and bones. Without adequate vitamin C, your immune system can be compromised, collagen may break down and you can experience increased inflammation. To sustain these everyday functions, women need 75 mg of vitamin C, and men require 90 mg.
Absorption of Supplements
You can absorb 70 to 90 percent of your vitamin C supplement as long as you keep your total daily dose to a minimal 30 to 180 mg per day, says the National Institutes of Health Office of Dietary Supplements. Ingesting 1 g or more per day decreases absorption to less than 50 percent. The overabundance of vitamin C travels through your gut as unmetabolized ascorbic acid, increasing distress in your stomach as your body works to excrete it.
While vitamin C is generally safe at high doses, too much can cause some discomfort. Consuming too much vitamin C at once can lead to stomach cramping, bloating and diarrhea, since your kidneys are pulling water to dilute it for excretion. These negative effects are unpleasant but are generally harmless and will resolve on their own. Avoid having these side effects by limiting your intake to less than 2,000 mg, or 2 g, according to the Linus Pauling Institute at Oregon State University. Having more than 10,000 mg, or 10 g, per day can cause serious health problems, such as kidney stones, birth defects and atherosclerosis.
Vitamin C in the Diet
Stomach upset from vitamin C can occur from too much vitamin C in your diet, not just from excessive vitamin C supplementation. A variety of fruits and vegetables are loaded with vitamin C. A 1/2-cup serving of red pepper slices has 95 mg, one medium kiwi provides 70 mg, 1 cup of whole strawberries offers 100 mg, a medium orange contains 70 mg and 1/2 cup of steamed broccoli provides 50 mg. Many of these foods, such as citrus fruits and peppers, cause stomach upset on their own because they are acidic or difficult to digest.
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This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.