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Vitamin C: An Essential Immunity Nutrient

April 28, 2020

Vitamin C and its Many Uses

Vitamin C is an essential nutrient for humans, needed for a vast array of bodily functions, such as proper wound healing. It’s a powerful antioxidant that neutralizes chemicals called free radicals that can damage cells. It’s also an important cofactor for many enzymes and is necessary for the production of various hormones. 

Vitamin C also plays a vital role in the immune system. It concentrates in immune cells, helping them to respond to and kill microbes, such as bacteria and viruses. If there’s a lack of Vitamin C in the body, the immune system does not function properly, leading to an increased chance of infection. 

Dietary Sources

Although most animals can make their own Vitamin C, humans cannot and our bodies don’t store it well. So, we need regular, daily, dietary intake to maintain sufficient levels. The best food sources of Vitamin C are fresh fruits and vegetables, specifically citrus fruits, peaches, peppers, papayas, strawberries, tomatoes, broccoli, spinach, and kiwis. 

Recommended Intake Amounts

The recommended daily amount of Vitamin C is 90 mg for men and 75 mg for women. The best way to get Vitamin C is from food sources and if you eat 5-7 servings of fresh fruits and vegetables daily, you’ll be getting 400-500 mg of Vitamin C each day. Since many of us don’t eat 5-7 serving of fruits and vegetables every day, a Vitamin C supplement may be needed to maintain sufficient levels.

Moreover, research data suggests that higher daily Vitamin C intake (at least 200 mg/day) is needed to help prevent infections and even more Vitamin C is required (1000 mg/day) to help replenish levels during active infections. 

Taking Too Much Vitamin C

Even though Vitamin C is water soluble and not stored in our bodies, there is a recommended upper limit for Vitamin C supplements, which is 2000 mg/day. Intaking more than this can cause GI upset and diarrhea. If you’re considering taking a Vitamin C supplement, it’s better to take smaller, more frequent doses, (for example, 250 mg 3 times per day, as opposed to 1000 mg once per day) as the body absorbs it better that way.

Vitamin C can interfere with the action of blood thinners. Patients on these medications should limit their intake to 1000 mg/day and talk with their doctor about the potential need for additional testing of blood clotting factors. High doses (1000 mg or more /day) of Vitamin C can also interfere with some lab tests, so it is a good idea to talk with your doctor about holding Vitamin C supplements for at least 24 hours before testing.

For more information discussed in this blog post, check out this research paper published by the University of Otago in New Zealand.