As the novel coronavirus continues to sweep the globe, patients and doctors alike are wondering what we can do to prevent and treat the infection. People struggling already with chronic illnesses like Lyme disease , fibromyalgia , and ME/CFS  (myalgic encephalomyelitis/chronic fatigue syndrome) are especially vulnerable and need ways to boost their immunity  and support their health. Vitamin C supplements have been flying off the shelves — and taking it may be a good idea — both to help protect against a variety of viruses  and to support general health. As humans are one of the few mammals who don’t produce Vitamin C endogenously (by ourselves), we must get it through food or supplements. Now is a good time to be sure you are getting enough. Let’s take a look at ways in which vitamin C may support people with chronic illnesses.
1. Vitamin C May Help with Respiratory Infections
It seems like common folk wisdom that if you’re fighting a cold, you reach for Vitamin C, or drink some hot lemon water (also an excellent natural source of C).
Dr. Mischa Grieder of San Francisco Preventive Medical Group  treats many patients working to heal chronic illness. Many of us want to be sure we’re doing all we can to protect ourselves, especially with coronavirus circulating. Recently, Dr. Grieder held a webinar  to educate his patients on the use of vitamin C to prevent respiratory infections and to limit the intensity of infections should you become sick.
In the webinar, Dr. Grieder discusses his experience that patients experiencing acute respiratory infection may be able to absorb higher doses of vitamin C as compared to when they are healthy. In his practice, he has seen patients fighting infection absorb much higher doses of vitamin C orally while they were sick and then needing to decrease that amount once their infections resolved. This may be in part because the body uses more Vitamin C to combat inflammation when we’re fighting a virus.
Dr. Grieder suggests different dosages of Vitamin C depending on whether you are healthy or fighting a respiratory infection. Be sure to consult your doctor to determine the dosage that’s right for you.
2. Vitamin C Reduces Free Radical Damage
One of the primary ways Vitamin C can support general health is by neutralizing free radicals. Free radicals, or reactive oxygen species, are a type of unstable molecule containing oxygen and an uneven number of electrons. The body generates free radicals in many normal, healthy processes. Mitochondria generate free radicals as they produce energy. Immune cells produce free radicals while fighting infection.
Unfortunately, tissue damage can occur when there are too many free radicals for the body to neutralize effectively. This can occur in cases of severe respiratory illness. In cases of chronic illness, lasting inflammation can also be a problem, and may exacerbate symptoms. Antioxidants, whether from dietary sources or supplements, may help. Enter vitamin C.
Vitamin C is an antioxidant. Antioxidants stabilize free radicals, or reactive oxygen species, by donating electrons. Once the free radicals have an even number of electrons, they become stable. This halts their damaging interactions with cells and tissue, lowering oxidative stress. People with chronic illness may be able to lessen symptoms of inflammation by making sure they are getting enough Vitamin C. Additionally, people fighting acute illness, such as a respiratory infection, may be able to lessen inflammatory symptoms by taking C as well.
3. Vitamin C Supports Immune Health
A 2013 study  on the antiviral properties of vitamin C looked at the effects of the influenza virus on a type of mice that, like humans, do not produce vitamin C on their own. The authors inoculated the mice intra-nasally with the influenza virus and monitored survival of those that were vitamin C deficient as compared with those that were not. The mice that were vitamin C deficient, when inoculated, all died within one week, even when given vitamin C supplements one day after inoculation. All the vitamin C sufficient mice survived.
Adequate stores of vitamin C before infection may assist the body with an appropriate immune response to viruses like influenza by bolstering the activity of the body’s natural killer (NK) cells, states the study. Regularly supplying your system with vitamin C may act as a preventative agent when it comes to combating flu symptoms.
4. Vitamin C Helps Build Collagen
Though it doesn’t relate to respiratory infection directly, it’s worth mentioning Vitamin C’s role in collagen  synthesis — as it’s so supportive for general health and pain management in the chronic illness community.
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Collagen is a protein found abundantly in our skin, joints, bones, muscles, and connective tissue. Collagen makes up one-third of the human body, so it’s hard to underestimate its importance! Collagen is super strong, creating long, thin fibrils that support and anchor the structures of the body. It essentially acts as the body’s structural scaffolding.
When it comes to healing damaged tissues, our bodies must be capable of synthesizing collagen (scarring mostly consists of collagen). Vitamin C is a critical component of collagen synthesis by helping to stimulate the formation of it. Furthermore, this crucial vitamin encourages the healing of bone fractures.
Further human studies are necessary to understand Vitamin C’s effect on collagen synthesis more clearly. But safe to say, sufficient dietary Vitamin C, or Vitamin C supplementation, could help to support healthy collagenous tissue. Vitamin C also may support skin health and resilience (just look at all the skin creams out there with added vitamin C).
Foods rich in Vitamin C
There are many delicious fruits and vegetables that are naturally high in vitamin C. Citrus is an obvious choice, including lime and lemon for those on a low sugar diet. Cruciferous vegetables from the cabbage family like broccoli, kale, brussels sprouts, and cauliflower are also high in Vitamin C. For salad lovers, radishes, and watercress are high in C. It’s not hard to incorporate a variety of these disease-fighting plants into your daily diet.
Now is the perfect time to be sure your immune system is robust . Making sure your body has a good supply of Vitamin C — through diet, supplementation, or both — as an optimal means to support health. Talk with your doctor about the best way for you to get vitamin C every day and the amount that’s right for your body.
Shona Curley lives and works in San Francisco. She is co-owner of the studio Hasti Pilates, and creator of the website www.redkitemeditations.com. Shona teaches meditation, bodywork and movement practices for healing Lyme disease, chronic illness and pain.
Grieder M. Dr. Mischa Grieder, Covid Update 3. Webinar . March 2020.
Kim Y, Kim H, Bae S, et al. Vitamin C Is an Essential Factor on the Anti-viral Immune Responses through the Production of Interferon-α/β at the Initial Stage of Influenza A Virus (H3N2) Infection. Immune Netw. 2013;13(2):70–74. doi:10.4110/in.2013.13.2.70 
Boyera N, Galey I, Bernard BA. Effect of vitamin C and its derivatives on collagen synthesis and cross-linking by normal human fibroblasts. National Institutes of Health Website. 1998 Jun;20(3):151-8. doi: 10.1046/j.1467-2494.1998 .
DePhillipo NN, Aman ZS, Kennedy MI, Begley JP, Moatshe G, LaPrade RF. Efficacy of Vitamin C Supplementation on Collagen Synthesis and Oxidative Stress After Musculoskeletal Injuries: A Systematic Review. Orthop J Sports Med. 2018;6(10):2325967118804544. Oct 25. doi:10.1177/2325967118804544