If you have painful peripheral neuropathy (weakness, numbness, and pain from nerve damage, usually in the hands and feet), you probably have a low level of vitamin D. But a new study concluded that taking a lot of vitamin D3 for a short term can improve the symptoms of neuropathy.
A low level of vitamin D is a "Fairly new topic of interest in pain," the Vanderbilt University Medical Center wrote in 2009. A review article in Pain on "Vitamin D and chronic pain" had just found that we needed better evidence to conclude that vitamin D is relevant.
Pain was significantly less in the treatment group
The new study provides some of the evidence that we needed. Published online and not yet assigned to an issue of Medical Principles and Practice, the study is "Prospective Evaluation of the Effect of Short-Term Oral Vitamin D Supplementation on Peripheral Neuropathy in Type 2 Diabetes Mellitus." A research team from Kuwait sequentially assigned 57 people with both type 2 diabetes and diabetic peripheral neuropathy to a treatment group, matching them with 55 similar people in a placebo group.
The treatment group took a capsule that contained 50,000 IU of Vitamin D3 once a week for eight weeks, while the placebo group got a starch capsule. Using the Neuropathy Symptom Score, a standardized measure, the reduction was "significantly greater in the treatment group than in the placebo group."
The researchers for this study defined vitamin D deficiency as a serum 25(OH)D concentration of less than 50 nmol/ml, which is equivalent to less than 20 ng/ml. This is less than the 30 ng/ml in a Diabetic Medicine study that found 81 percent of American adults with diabetes to have insufficient vitamin D. At the same time, "About 60 to 70 percent of people with diabetes have some form of neuropathy," according to the National Institutes of Health.
Most people don’t know their vitamin D level
If you have had diabetes for a few years, the chances are that you have neuropathy. You probably know if you have it, either from chronic pain or because a doctor told you. But the big problem is that most people with diabetes don’t know what their blood level of Vitamin D is (technically known as 25(OH)D or 25-hydroxyvitamin D).
In the 21 years since a doctor told me that I have type 2 diabetes, no doctor ever checked my level until a few years ago when I specifically asked for it. But I often get it checked at GrassRoots Health, and last month they told me that my level was 69 ng/ml, essentially the same level as the lab test my doctor had ordered earlier. Since I take 5,000 IU of vitamin D3 daily, I wasn’t surprised.
Several years ago a doctor told me that the usual test showed him that I have neuropathy. But my doctors now tell me that I have reversed it. Meanwhile, I have lost weight, keep my blood sugar under better control, and take enough vitamin D.
Totally reversing diabetic peripheral neuropathy takes careful diabetes management and years of effort. But reversing at least some of its chronic pain may be a lot easier and quicker.
See more of my articles about how to manage diabetes:
David Mendosa was a journalist who learned in 1994 that he had type 2 diabetes, which he wrote about exclusively. He died in May 2017 after a short illness unrelated to diabetes. He wrote thousands of diabetes articles, two books about it, created one of the first diabetes websites, and published a monthly newsletter, “Diabetes Update.” His very low-carbohydrate diet, A1C level of 5.3, and BMI of 19.8 kept his diabetes in remission without any drugs until his death.