Vitamin B12 & the Nerves

Vitamin B-12 fills a number of physiological roles -- it contributes to the formation of red blood cells and helps in the synthesis of DNA, the genetic code found in your cells. It also plays a key role in the health of your nervous system. If you’re not getting enough B-12, you risk developing serious nerve damage.


B-12 Basics

B-12 is one of eight B vitamins. All of the B vitamins are water-soluble, meaning any excess amounts you consume aren’t stored in your body, but are excreted in your urine. B-12 bucks the water-soluble trend by accumulating in your liver, which stores amounts that could keep your body supplied with enough to last up to 5 years, according to the Merck Manuals Online Medical Library. This is why a B-12 deficiency can take a long time to surface. B-12 is only derived from animal food sources, such as milk, fish, eggs and meat. If you’re a strict vegan, you’ll need to obtain B-12 through supplements or by eating foods such as cereal fortified with B-12 from animal sources.

B-12 and the Nervous System

The exact mechanisms by which B-12 contributes to a healthy nervous system are unclear, though the Linus Pauling Institutes states that B-12 may be linked to the structure of the myelin sheath. Myelin forms an insulating layer that covers your nerve cells. It functions in speeding up neural transmissions as they travel along one nerve cell, toward neighboring cells. When you are deficient in B-12, you may experience neurological symptoms such as tingling in the hands and feet, as well as depression or a decrease in cognitive functioning.

Long Term Complications

The neurological effects of B-12 develop gradually, and if addressed in time, may be completely reversed. With untreated, chronic B-12 deficiency, you're likely to develop longer-term effects caused by prolonged damage to your nervous system. If your long term B-12 deficiency is not treated properly and in time, your neurological symptoms can be permanent.

Additional Risks

In addition to neurological effects, a B-12 deficiency can also lead to megaloblastic anemia, a condition where your body doesn’t produce enough red blood cells, and those it does produce tend to be immature and abnormally large. This condition can also result from a folate deficiency, and as a result B-12 deficiencies are sometimes erroneously treated with folate supplementation. This mistake can cause serious repercussions, as folate supplementation can indeed correct megaloblastic anemia caused by B-12 deficiency, but will do nothing to correct the neurological effects. If you have megaloblastic anemia, it is important that your doctor order diagnostic tests to determine the cause of the disorder.


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