CMT, or Charcot-Marie-Tooth disease, is a genetic disorder that affects nerves. The National Institute of Neurological Disorders and Stroke reports that CMT is one of the most common inherited neurological diseases, affecting an estimated 1 in 2,500 Americans. There are at least five forms of CMT, one of which, identified as CMT1, occurs in two-thirds of all cases. Symptoms, including weakness in the foot and lower leg muscles, typically present in adolescence or early adulthood.
Treatment
There's no cure for CMT. The most common treatments include physical therapy, wearing an orthopedic device, pain-killing medications and, in extreme cases, surgery. The goal of physical therapy is to increase muscle strength and stamina and to stretch ligaments. The earlier a patient begins occupational therapy, the better. Muscle strengthening can delay onset of symptoms and reduce muscle weakness. Once atrophy and muscle degeneration sets in, it's more difficult to reverse. Stretching helps prevent bone deformities caused by uneven muscle tension. Because it takes more energy to perform ordinary tasks, people with CMT are prone to fatigue, which physical therapy can help reduce.
Vitamin C
In a 2004 study published in "Nature Medicine," researchers found that mice with CMT treated with vitamin C performed better on motor tests than mice not treated with the vitamin. Motor skills refer to coordinated movements that rely on the use of small and large muscle groups. A higher percentage of nerves associated with CMT were present in the mice given vitamin C, and the nerves had a thicker protective covering. Vitamin C was also linked to extending the lifespan of animals with the neurological disease.
Human Study
In 2005, researchers from the Institute for Neuromuscular Research in Australia tested the safety and efficacy of vitamin C on children with CMT. The study, results of which were reported in 2009 in "The Lancet Neurology," analyzed the effect of high-dose, oral vitamin C supplementation on 81 children. After one year, the children who had been given the vitamin showed an insignificant increase in symptoms involving affected nerves. There was no difference in strength, function and quality of life between the children on the vitamin and those who received a placebo. According to the editor, however, five children who exhibited the greatest increase in nerve function were in the group that received the vitamin.
Considerations
Davide Pareyson, M.D., a member of the National Neurological Institute in Italy, reports that it's possible that vitamin C will work in humans with CMT much the same was as it does in mice. He theorizes that since there is no cure for the disease and because vitamin C is very safe, there's no reason not to pursue it as a treatment option. The recommended daily allowance, or RDA, of vitamin C for healthy adults is between 65 mg and 120 mg, depending on gender, pregnancy and breast-feeding status. For children, the RDA is from 15 mg to 75 mg. Katherine Zeratsky, a registered dietician at the Mayo Clinic, reports that too much vitamin C is unlikely to be harmful, but megadoses can result in gastrointestinal discomfort, headaches, insomnia or kidney stones. Current studies, according to Dr. Pareyson, are looking at the possible benefits of vitamin C supplements of 1,500 mg for adults. The trial reported in "The Lancet Neurology" consisted of 30 mg of vitamin C supplements in kids 2 to 16 years of age.
References
- The National Institute of Neurological Disorders and Stroke: Charcot-Marie-Tooth Disease Fact Sheet; February 2011
- Linus Pauling Institute, Oregon State University; Vitamin C for the Treatment of Charcot-Marie-Tooth Disease; Davide Pareyson, M.D.; June 2006
- "Nature Medicine"; Ascorbic Acid Treatment Corrects the Phenotype of a Mouse Model of Charcot-Marie-Tooth Disease; Edith Passage, et al.; March 2004
- "The Lancet Neurology"; Ascorbic Acid for Charcot-Marie-Tooth Disease Type 1A in Children; Joshua Burns, Ph.D., et al.; June 2009
- Office of Dietary Supplements, National Institutes of Health; Vitamin C; March 2010
- MayoClinic.com; Too Much Vitamin C: Harmful?; Katherine Zeratsky, R.D., L.D.; March 2010
Member Comments