The relationship between diabetes and vitamin B12 is complex, and research is constantly uncovering new insights. If you have diabetes and take a medication like Metformin, you may have been told that you’re at greater risk of being deficient in vitamin B12. This is worth knowing since vitamin B12 is so important for a variety of functions in the body, including decreasing your risk of developing neuropathy (1). Read on to learn what diabetic neuropathy is, the connection between vitamin B12 and diabetes, and whether supplementation is necessary.
What is Diabetic Neuropathy?
Diabetic neuropathy is nerve damage that stems from diabetes. Those with diabetic neuropathy often suffer from some of the following symptoms (2):
- Numbness
- Tingling or burning sensation
- Pain or cramping, especially in the hands and feet
- Oversensitivity
- Foot issues such as ulcers, infections, and loss of sensation
Eating a well-balanced diet and keeping blood sugar under control helps tremendously with preventing and reducing diabetic neuropathy symptoms. Recent studies show that vitamin B12 may also play a role in improving symptoms of diabetic neuropathy (3-5). However, many people with diabetes also have insufficient levels of vitamin B12 that they are unable to restore through diet alone (6). Because of this, supplementation is often recommended, but always be sure to speak with a healthcare professional before adding any supplements to your routine.
Importance of Vitamin B12
Vitamin B12 plays an important role in a variety of the body’s functions. It’s needed for creating red blood cells (and helping prevent anemia) and for keeping our brain and nerves functioning properly (7). Vitamin B12 intake is especially critical for those with diabetes due to an increased risk of inadequacy and the additional danger of neuropathy.
There are a few causes for low or insufficient levels of vitamin B12. One primary reason for deficiency among diabetes patients is that the medication commonly used in treatment prevents the absorption of vitamin B12, resulting in a greater risk for low levels (6). Deficiency has been seen with the use of Metformin specifically, with the risk of deficiency increasing with dosage and length of time on the medication. Other medications that have been shown to result in lower levels of vitamin B12 include proton pump inhibitors and histamine blockers (8). Here are a couple of other contributors to vitamin B12 deficiency:
- Being vegan or vegetarian
many vitamin B12-rich foods come from animal sources
- Gastrointestinal conditions
due to decreased absorption
Can Supplements Help?
Recent studies have found vitamin B12 supplementation to have a positive impact on diabetic neuropathy for people who have insufficient levels of vitamin B12 (3-5). However, more research still needs to be done on whether additional supplementation is as effective for those with adequate vitamin B12 levels. Since many people with diabetes are taking medications that contribute to lower levels of vitamin B12, the American Diabetes Association notes that supplementation may be beneficial (6). Additionally, vitamin B12 is a water-soluble vitamin, meaning that you are unlikely to experience negative side effects and will simply excrete out any excess through urine.
For dosing, studies have found 1000 mcg of vitamin B12 to be safe and effective in improving diabetic neuropathy, but be sure to always speak with a health professional before starting a new supplement and for your specific dosing recommendation (5). When looking at supplements, you want to find one that is third-party tested to ensure quality and an uncontaminated product.
References
(1) Alvarez M, Sierra OR, Saavedra G, Moreno S. Vitamin B12 deficiency and diabetic neuropathy in patients taking metformin: a cross-sectional study. Endocr Connect. 2019;8(10):1324-1329. doi:10.1530/EC-19-0382
(2) What is diabetic neuropathy? – niddk. National Institute of Diabetes and Digestive and Kidney Diseases. Accessed February 14, 2024. https://www.niddk.nih.gov/health-information/diabetes/overview/preventing-problems/nerve-damage-diabetic-neuropathies/what-is-diabetic-neuropathy#symptoms-dn.
(3) Trippe, B.S.; Barrentine, L.W.; Curole, M.V.; Tipa, E. Nutritional management of patients with diabetic peripheral neuropathy with L-methylfolate-methylcobalamin-pyridoxal-5-phosphate: Results of a real-world patient experience trial. Curr. Med. Res. Opin. 2016, 32, 219–227
(4) Fonseca VA, Lavery LA, Thethi TK, et al. Metanx in type 2 diabetes with peripheral neuropathy: a randomized trial. Am J Med. 2013;126(2):141-149. doi:10.1016/j.amjmed.2012.06.022
(5) Didangelos T, Karlafti E, Kotzakioulafi E, Margariti E, Giannoulaki P, Batanis G, Tesfaye S, Kantartzis K. Vitamin B12 Supplementation in Diabetic Neuropathy: A 1-Year, Randomized, Double-Blind, Placebo-Controlled Trial. Nutrients. 2021; 13(2):395. https://doi.org/10.3390/nu13020395
(6) Vitamins & supplements. Vitamins & Supplements for Diabetes | ADA. Accessed February 14, 2024. https://diabetes.org/food-nutrition/diabetes-vitamins-supplements.
(7) O’Leary F, Samman S. Vitamin B12 in health and disease. Nutrients. 2010;2(3):299-316. doi:10.3390/nu2030299
(8) Some supplements might help ease nerve damage symptoms. Mayo Clinic. January 27, 2024. Accessed February 14, 2024. https://www.mayoclinic.org/diseases-conditions/diabetic-neuropathy/in-depth/diabetic-neuropathy-and-dietary-supplements/art-20095406.
