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Vitamin

Vitamin C

Vitamin C, or ascorbic acid, is an essential water-soluble vitamin that humans cannot make, found in fruits and vegetables such as citrus, peppers and berries.

Also listed as Ascorbic Acid, Ascorbate, L-ascorbic acid

Essential HealthLongevityImmune SupportCardiovascularHair & Skin

Can high doses cause problems?

High doses can cause diarrhea, nausea and abdominal cramps. The US adult upper intake level is 2,000 mg daily from all sources, including during pregnancy and lactation in adults; children have lower limits. An upper limit is not a target intake. 1

Who needs particular caution?

Kidney-stone findings are inconsistent overall, but concern is greater with kidney disorders and pre-existing high urinary oxalate. In hereditary hemochromatosis, chronic high doses may worsen iron overload. These conditions change the interpretation of a product’s apparently simple vitamin label. 1

What matters during cancer treatment?

Interactions between antioxidant supplements and chemotherapy or radiation remain clinically important and debated. NIH advises discussion with the oncology team before vitamin C or other antioxidant supplements, particularly at high doses. Oral supplement claims should not be inferred from experimental intravenous cancer-treatment research. 1

For information, not individual medical advice. Ingredient studies do not establish the effectiveness of these products.

Sources

  1. Vitamin C: Fact Sheet for Health Professionals NIH Office of Dietary Supplements