How does vitamin C help the immune system?

How Vitamin C supports the immune system

Vitamin C supports a whole host of body functions: immune health,¹ collagen production,² antioxidant protection,³ iron absorption,⁴ heart health,⁵ and brain function⁶—and even skin health⁷ (it can be applied topically). While its direct effect on the immune system continues to be studied,⁸ its aggregate benefits contribute to a strong, supported, functioning body.
If you’re thinking of taking Vitamin C for immune health, here’s our 101.
It’s an ongoing question in the medical field: Does taking vitamin C actually help your immune system? Well, it’s a little complicated.
While more recent studies are less conclusive about the claim that vitamin C can directly impact specific immune outcomes,⁹ it cannot be denied that general, daily intake of Vitamin C supports your body’s many functions and helps optimize your overall health.
However, by acting as an antioxidant and supporting your body’s essential functions, vitamin C does support immune health.
To clarify:

• How does vitamin C help your body when your immune system is active? By tending to many of your body’s functions and other needs, Vitamin C supports your immune system responses by making sure the whole body is supported.
• How does vitamin C help the immune system? By supporting the whole system of well-being through strong antioxidant support, collagen production, iron absorption, and more.

Recommended daily intake of Vitamin C

How much Vitamin C you need depends on your age, sex, and certain lifestyle factors. While you are consuming a balanced diet (especially if they’re foods like oranges, bell peppers, or the occasional kiwi), you may still have gaps in your necessary intake.
The daily recommended intake for adults is 75–90 mg.¹⁰ However, if you’re in the category of people who might not be getting enough of the vitamin for various reasons—for instance, people who eat very few fruits and vegetables,¹¹ older adults with limited diets, and people with conditions that might affect nutrient absorption—then supplementation can help ensure adequate Vitamin C intake.
As a supplement, AG1’s formula contains over 500 mg of Vitamin C, which is 556% of the recommended daily value—an amount that will surpass your baseline needs and ensure you’re getting enough, even with varying lifestyle factors and nutritional needs.

Sources of Vitamin C for immune support

Many fruits and vegetables are natural Vitamin C sources. Here are some tasty foods that will boost your vitamin C while providing a little diversity in your diet:

• Oranges and other citrus fruits: One medium-sized orange typically contains between 70 and 83 mg.
• Kiwi: A super high source, a medium kiwi contains 64 mg.
• Strawberries: One cup provides about 97 mg.
• Guava: A guava typically contains around 125–230 mg.
• Papaya: A medium-sized papaya contains approximately 95.6 mg.
• Pineapple: One cup of fresh pineapple chunks contains about 79 mg.
• Mango: One cup of mango contains about 45–60 mg.
• Red bell peppers: A medium-sized red bell pepper contains approximately 106–150 mg.
• Broccoli and Cauliflower: ½ cup of boiled broccoli has 50.6 g, and ½ cup of boiled cauliflower has 27.5 g.
• Brussels sprouts: One cup of raw Brussels sprouts contains approximately 74–75 mg of Vitamin C.
• Kale: One cup of raw, chopped kale contains approximately 80 mg of Vitamin C.
• Spinach: 8.43 mg per cup.
• Tomatoes: A medium-sized raw tomato contains approximately 17–20 mg of vitamin C.

For more information on which foods have the most vitamin C, head to nutrition.gov for certified nutritional content.
Our recommendation: Fill up on fruits and vegetables. But if you can’t or don’t eat certain foods, supplements can help minimize the gaps and your vitamin goals.

Supporting your immune function with Vitamin C

Consuming Vitamin C is a smart part of your consistent effort to care for your overall well-being. Prioritize it daily (and if you’re already drinking AG1, our greens powder, you know it’s in the formula every day) to help you function your best on many biomolecular levels.

References:

1. Carr AC, Maggini S. Vitamin C and Immune Function. Nutrients. 2017;9(11):1211. Published 2017 Nov 3. doi:10.3390/nu9111211
2. Boyera N, Galey I, Bernard BA. Effect of vitamin C and its derivatives on collagen synthesis and cross-linking by normal human fibroblasts. Int J Cosmet Sci. 1998;20(3):151-158. doi:10.1046/j.1467-2494.1998.171747.x
3. Padayatty SJ, Katz A, Wang Y, et al. Vitamin C as an antioxidant: evaluation of its role in disease prevention. J Am Coll Nutr. 2003;22(1):18-35. doi:10.1080/07315724.2003.10719272
4. Teucher B, Olivares M, Cori H. Enhancers of iron absorption: ascorbic acid and other organic acids. Int J Vitam Nutr Res. 2004;74(6):403-419. doi:10.1024/0300-9831.74.6.403
5. Juraschek SP, Guallar E, Appel LJ, Miller ER. Effects of vitamin C supplementation on blood pressure: a systematic review and meta-analysis of clinical trials. Am J Clin Nutr. 2012;95(5):1079-1088. doi:10.3945/ajcn.111.027995
6. Harrison FE, May JM. Vitamin C function in the brain: vital role of the ascorbate transporter SVCT2. Free Radic Biol Med. 2009;46(6):719-730. doi:10.1016/j.freeradbiomed.2008.12.018
7. Pullar JM, Carr AC, Vissers MCM. The Roles of Vitamin C in Skin Health. Nutrients. 2017;9(8):866. Published 2017 Aug 12. doi:10.3390/nu9080866
8. Lykkesfeldt J, Poulsen HE. Is vitamin C supplementation beneficial? Lessons learned from randomised controlled trials. Br J Nutr. 2010;103(9):1251-1259. doi:10.1017/S0007114509993229
9. Lykkesfeldt J, Poulsen HE. Is vitamin C supplementation beneficial? Lessons learned from randomised controlled trials. Br J Nutr. 2010;103(9):1251-1259. doi:10.1017/S0007114509993229
10. Institute of Medicine (US) Panel on Dietary Antioxidants and Related Compounds. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington (DC): National Academies Press (US); 2000. 5, Vitamin C. Available from: https://www.ncbi.nlm.nih.gov/books/NBK225480/
11. Institute of Medicine (US) Panel on Dietary Antioxidants and Related Compounds. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington (DC): National Academies Press (US); 2000. 5, Vitamin C. Available from: https://www.ncbi.nlm.nih.gov/books/NBK225480/