Does High-Dose Vitamin C Treat Charcot-Marie-Tooth?

No, you should not take high-dose Vitamin C to treat Charcot-Marie-Tooth disease (CMT). While there were once widespread rumors and high hopes that Vitamin C could help, multiple high-quality, international clinical trials have definitively proven that it does not slow down or improve the symptoms of the condition ^[1][2]. Furthermore, taking high doses of Vitamin C is not harmless; it can significantly increase your risk of developing kidney stones ^[3][4].

(Note: Normal dietary amounts of Vitamin C—like what you get from eating fruits and vegetables or taking a standard daily multivitamin—are completely safe and necessary for your general health. The warnings here apply strictly to taking large, high-dose supplements ^[5][6].)

The Origin of the Vitamin C Myth

The excitement around Vitamin C (also known as ascorbic acid) began years ago following early laboratory research. In initial studies involving a mouse model of CMT1A (the most common subtype of CMT), researchers discovered that giving the mice high doses of Vitamin C seemed to reduce the production of a specific gene called PMP22 ^[2]. This gene provides instructions for making a protein that forms the protective coating (myelin) around your nerves. In these mice, the treatment improved their motor function (muscle strength and movement) and increased the health of their peripheral nerves ^[2].

Because Vitamin C is widely available and generally considered safe, these findings quickly sparked hope and rumors within the CMT patient community. Many people began taking large doses of the supplement, hoping for similar improvements.

What the Clinical Trials Actually Showed

To see if the results from the mouse models would translate to humans, researchers launched several large-scale, international clinical trials across France, Belgium, Italy, the UK, and other countries ^[1][2]. In these studies, patients with CMT1A were given daily doses of Vitamin C ranging from 1 to 4 grams ^[1].

Unfortunately, the results were universally disappointing. The trials consistently demonstrated that high-dose Vitamin C does not improve muscle strength, alter nerve conduction abnormalities, or slow the progression of the disease ^[1][2][7]. Comprehensive reviews of all this data have concluded that Vitamin C provides no clinical benefit for either adults or children with CMT1A ^[1]. While the initial trials focused on the CMT1A subtype because of the PMP22 gene connection, the medical consensus is that high-dose Vitamin C is not an effective treatment for any type of CMT ^[2].

The failure of these trials highlights a common, albeit deeply frustrating, challenge in medical research: what works in animal models does not always work in humans ^[2][8].

The Hidden Risks: Why “It Can’t Hurt” Isn’t True

When you have a progressive condition with no cure, it is completely natural to want to try anything that might help, especially something that seems harmless like a vitamin. However, taking high-dose supplements carries real risks.

When your body breaks down large amounts of Vitamin C, it converts it into oxalate, a substance that gets excreted in your urine ^[3][9]. High levels of oxalate in the urine are a primary building block for calcium oxalate kidney stones ^[3]. Studies have shown that taking supplemental Vitamin C significantly increases the risk of developing these painful stones, particularly in susceptible individuals and in men ^[10][4].

It is incredibly difficult and frustrating to live with a condition where there is currently no medical cure to stop the progression. However, because there is no evidence that high-dose Vitamin C helps any form of CMT, and clear evidence that it can cause kidney stones, it is best to avoid using it as a treatment ^[2][1]. Instead, work closely with your neurology team to build a care plan around proven management strategies, such as physical therapy and orthotics, while keeping an eye out for actual upcoming clinical trials.