Vitamin B12 is a water-soluble vitamin that is naturally found in some foods and added to others. Vitamin B12 can also be supplemented in oral and injectable forms. You might be surprised by the statistics on B12 deficiency. The prevalence of vitamin B12 deficiency is approximately 6% in persons younger than age 60 and nearly 20% in those older than age 60 in both the United States and the United Kingdom (Hunt et al. 2014). In developing countries, the rate of B12 deficiency is even higher. Foods high in vitamin B12 include meats and dairy products such as fish, shellfish, organ meats, eggs, beef, and pork.
Vitamin B12 comes in two forms that are active in human metabolism, methylcobalamin and 5-deoxyadenosylcobalamin (Institute of Medicine, 1998). Vitamin B12 is required to form red blood cells in the body, for proper neurological function, and for the synthesis of DNA (NIH, n.d). When reviewing the symptoms of B12 deficiency, you may notice that many of them are secondary to the effects of anemia and others to malfunctioning brain cells. A lack of red blood cells or abnormally formed red blood cells can really impact your energy levels, motivation, ability to think clearly, and overall health. A deficiency of B12 and its effects on the nervous system can masquerade as several other diseases and disorders, making assigning an accurate diagnosis very challenging.
When bound to the food we eat, Vitamin B12 is released by hydrochloric acid in the stomach, along with an enzyme called gastric protease. When vitamin B-12 is added to food or taken as a supplement, it is already in a free form and does not need to be released. Once vitamin B-12 is free, it combines with intrinsic factor. Intrinsic factor is a glycoprotein secreted by specialized cells lining the stomach called parietal cells. The combined intrinsic factor-vitamin B12 is absorbed into the body in the ileum, which is the most distal part of the small intestine (NIH, n.d.).
Studying the absorption pathway for B12 you may note four possible impediments to absorbing adequate vitamin B-12.
Other groups of people at risk for B12 deficiency include:
Age | Male | Female |
0-6 months | 0.4 mcg | 0.4 mcg |
7–12 months | 0.5 mcg | 0.5 mcg |
1–3 years | 0.9 mcg | 0.9 mcg |
4–8 years | 1.2 mcg | 1.2 mcg |
9–13 years | 1.8 mcg | 1.8 mcg |
14+ years | 2.4 mcg | 2.4 mcg |
In the United States, the average intake is 3.4 mcg per day, which means that the average person who eats an omnivore diet is at low risk (Institutes of Medicine, 1998).
If you have any of the following, speak with a health care provider before supplementing with vitamin B12 in any form:
Screening people for vitamin B12 deficiency is not usually recommended, but it should be done in those with risk factors or have symptoms consistent with vitamin B12 deficiency (U.S. Services Preventative Task Force, 2010). A blood test for vitamin B12 levels and a complete blood count to rule-out anemia start the evaluation. A level of vitamin B12 less than 150 pg per mL is diagnostic for deficiency. These levels must be evaluated by a health care professional since alcoholism, liver disease, and cancer can falsely elevate vitamin B12 levels. The risks and benefits of vitamin B12 deficiency are closely tied to folic acid, which may confound the clinical picture (Langan & Goodbred, 2017).
Guidelines from the British Society of Haematology recommend treating those with an irreversible cause indefinitely and those with a reversible cause until the deficiency has resolved (Hunt, Harrington, & Robinson, 2014).
Purchasing B12 shots at home as a treatment for vitamin B12 deficiency can effectively manage and treat your condition. The injections are relatively easy and painless to administer, and you can do it all from the comfort of your own home. Vitamin B12 injections require a prescription. Several serious diseases can overlap with the symptoms of B12 deficiency, so it is essential that you receive an accurate diagnosis.
Once you’ve conferred with your doctor, and they have written you a prescription, it is essential to choose a high-quality B12 supplement to treat your deficiency. Invigor Medical provides high-quality medical treatment plans, with high quality medications.
While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.
References: