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What Causes Pernicious Anemia

What Causes Pernicious Anemia

What Causes Pernicious Anemia – And How To Treat It

A decreased level of intrinsic factor production in the stomach is what causes pernicious anemia. Also known as Biermer’s Disease, pernicious anemia is an autoimmune disorder that prevents red blood cells from carrying sufficient oxygen to the body’s organ systems and tissues. It occurs when the immune system attacks and destroys healthy cells in the stomach called parietal cells, which are responsible for producing a substance called Intrinsic Factor (IF). The IF is essential for the absorption of vitamin B12 which is required for healthy red blood cell production.1

Intrinsic factor is a protein that binds to Vitamin B12 and helps it be absorbed in the intestine. A decrease in IF production can occur when autoimmune antibodies attack the cells of the stomach that produce IF, causing them to become damaged or destroyed. 

Low levels of IF can also be caused by diseases such as Crohn’s disease or celiac disease, surgery involving the stomach and/or small intestine, or a strict vegetarian diet. In addition, some medications and radiation treatments may interfere with IF production. Finally, aging itself can reduce the ability of the stomach to produce IF. Regardless of the cause, if IF is not present, the body is unable to absorb Vitamin B12, and anemia results.2

Without treatment, pernicious anemia can have serious consequences. Symptoms may become severe, including confusion, nerve damage in the arms and legs, difficulty walking, loss of balance and coordination, depression, heart problems, and other complications. Early diagnosis and treatment with vitamin B12 injections can help prevent these complications and restore health.3

What Causes Pernicious Anemia

How Common Is Pernicious Anemia?

Pernicious anemia is a rare disorder and affects around 1 in 1,000 people. It is more common among those of Northern European descent and the elderly. In the United States, it typically affects nearly 2% of individuals over 60 years old. While it is not a genetic disease, close family members can have a higher risk of developing pernicious anemia if one member is diagnosed.4

What Causes Pernicious Anemia

Pernicious anemia leads to the deterioration of the gastric mucosa, particularly in the fundic region, through an autoimmune reaction mediated by cells. Atrophy is associated with decreased gastric acid secretion, decreased intrinsic factor (IF) production, and impaired absorption of vitamin B12. This can be resolved through the supplementation of IF.5

What Is The Function Of Vitamin B12?

A lack of Vitamin B12 absorption is what causes pernicious anemia. Vitamin B12 is an essential nutrient that plays a crucial role in many bodily processes. It helps to form red blood cells, produce myelin, the protective sheath around nerve cells, and synthesize DNA. Vitamin B12 also contributes to energy production, metabolism regulation, and nervous system health.6

Vitamin B12 Deficiency Responsible For Neurological Impairment

Vitamin B12 deficiency can cause severe neurological impairment, including problems with memory, motor control, concentration, and coordination. Symptoms may include fatigue, confusion, poor balance, numbness and tingling of the arms and legs, difficulty walking or talking, and vision changes. If left untreated, it can lead to permanent nerve and brain damage.7

What Causes Pernicious Anemia - Vitamin B12

Pernicious Anemia And Autoimmune Thyroiditis

Pernicious anemia and autoimmune thyroiditis are two conditions that can occur together. Autoimmune thyroiditis occurs when the immune system mistakenly attacks the thyroid gland, leading to hypothyroidism and a host of other symptoms.

When these two conditions occur together, it is known as autoimmune polyglandular syndrome type 2 (APS-2). People with APS-2 may have both anemia and hypothyroidism, as well as an increased risk for other autoimmune diseases such as Addison’s disease. Treatment for APS-2 typically involves taking medications to manage anemia and hypothyroidism, as well as prevent the development of other autoimmune conditions. In addition, lifestyle changes such as avoiding certain foods and eating a healthy diet can help manage symptoms and reduce the risk of further complications.9

Read more about autoimmune thyroiditis.

Pernicious Anemia And Addison’s Disease

Pernicious Anemia and Addison’s Disease are two conditions that affect the adrenal glands. Addison’s Disease is an endocrine disorder in which the adrenal glands produce too few hormones. Symptoms of Addison’s Disease include fatigue, muscle weakness, darkening of the skin, known as hyperpigmentation, and low blood pressure with fainting episodes. 

Both conditions can be serious if left untreated. Treatment for both conditions typically involves taking medications to replace the hormones and vitamins that are lacking. Additionally, lifestyle changes such as increasing physical activity, reducing stress, getting regular sleep, and eating a healthy diet can help patients manage their symptoms. In severe cases of both Pernicious Anemia and Addison’s Disease, surgery may be necessary to remove the affected area of the adrenal gland.10

Read more about Addison’s Disease.

Pernicious Anemia And Celiac Disease

People with celiac disease may have a higher risk of developing pernicious anemia, as the two conditions share many similar symptoms and underlying causes. People with celiac disease are unable to properly absorb vitamins and minerals from food due to damage to the small intestine caused by eating gluten. This can lead to a deficiency in vitamin B12, which is necessary for the production of healthy red blood cells and is the main cause of pernicious anemia.11

Read more about Celiac Disease.

Pernicious Anemia And Rheumatoid Arthritis

While the exact cause of rheumatoid arthritis (RA) is unknown, studies have suggested that there may be a link between pernicious anemia and RA. There are several theories that suggest a connection between pernicious anemia and RA. One theory is that vitamin B12 deficiency may trigger an autoimmune response in the joints, leading to inflammation and joint destruction associated with RA. Additionally, some studies have found higher levels of antibodies against intrinsic factor in people with RA compared to those without the condition, suggesting a possible link.

Although there is no definitive proof that pernicious anemia causes RA, it may be a factor in the development of the condition. People with pernicious anemia should monitor their symptoms closely and consult their healthcare provider if they experience any joint swelling or pain. Additionally, people with RA should talk to their doctor about being tested for vitamin B12 deficiency as a possible contributing factor to their condition. Taking steps to ensure adequate vitamin B12 levels in the body may help reduce inflammation and other symptoms associated with RA.12

Read more about Rheumatoid Arthritis.

Pernicious Anemia And Rheumatoid Arthritis

Pernicious Anemia And Sjogren’s Syndrome

Pernicious anemia and Sjogren’s syndrome, two autoimmune conditions, often occur together. While the exact connection between them is still being studied, it appears that they may be linked by a shared immune response or genetic predisposition. Research has indicated that patients with one condition are at higher risk of developing the other.

For those with Pernicious Anemia, Sjogren’s Syndrome symptoms can include dry eyes and mouth, joint pain, fatigue, and swollen glands. These same symptoms can also be associated with Pernicious Anemia. Additionally, people who have both conditions may experience an increased risk of developing other autoimmune diseases such as rheumatoid arthritis or lupus.

The exact cause of the connection between Pernicious Anemia and Sjogren’s Syndrome is unknown. However, one theory is that they may be caused by a shared immune response or genetic predisposition. For instance, it has been suggested that a type of immunoglobulin called IgM might play a role in the development of both conditions.

The good news is that treatments are available to help manage symptoms for both Pernicious Anemia and Sjogren’s Syndrome. These include hormone replacement therapy, vitamin B12 injections, and medications to reduce inflammation or regulate immune system activity.9

Read more about Sjogren’s Syndrome.

What Causes Pernicious Anemia – And How To Treat It

While most people can get enough vitamin B12 through food alone, supplementation is necessary for individuals with pernicious anemia. When supplementing with vitamin B12, there are several different forms available. These include cyanocobalamin, methylcobalamin, and hydroxocobalamin. 

Cyanocobalamin is the most common form of vitamin B12 found in supplements. This type is easily absorbed by the body and doesn’t need to be converted for use. It’s also stable when exposed to light or air and can be stored without degradation over time. Methylcobalamin and hydroxycobalamin are active forms of vitamin B12 that are more bioavailable than cyanocobalamin. These forms are better for people who have difficulty converting B12 from food sources.

When choosing a supplement, it’s important to consider the dose. The recommended daily allowance (RDA) for adults is 2.4 mcg. A higher dose may be necessary for people with pernicious anemia or other conditions that interfere with vitamin B12 absorption. It’s also important to read the label and ensure the supplement contains only vitamin B12 and no other additives.13 14 15

What Causes Pernicious Anemia - Vitamin B12

Vitamin B12 injections are a convenient way to supplement your diet with this essential vitamin. When using Vitamin B12 shots as a supplement, it is important to follow the dosage instructions given by your healthcare provider. Generally, Vitamin B12 shots are administered intramuscularly and will be given at regular intervals to ensure that you are getting the proper amount of the vitamin. The frequency of injections can vary depending on the individual’s needs, and it is important to not exceed the recommended dosage.

In addition, when using Vitamin B12 injections as a supplement, there are some important safety considerations. Before using Vitamin B12 injections, it is important to ensure that you are currently not taking any other medications or supplements as certain combinations could cause an interaction. It is also important to make sure the injection site is clean and free of any infection.16

Read more about what causes autoimmune conditions.


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3 Andrès E, Fothergill H, Mecili M. Efficacy of oral cobalamin (vitamin B12) therapy. Expert Opin Pharmacother. 2010 Feb;11(2):249-56. doi: 10.1517/14656560903456053. PMID: 20088746.

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7 Health Quality Ontario. Vitamin B12 and cognitive function: an evidence-based analysis. Ont Health Technol Assess Ser. 2013 Nov 1;13(23):1-45. PMID: 24379897; PMCID: PMC3874776.

8 Alonso N, Granada ML, Salinas I, Lucas AM, Reverter JL, Juncà J, Oriol A, Sanmartí A. Serum pepsinogen I: an early marker of pernicious anemia in patients with type 1 diabetes. J Clin Endocrinol Metab. 2005 Sep;90(9):5254-8. doi: 10.1210/jc.2005-0580. Epub 2005 Jul 19. PMID: 16030155.

9 Feld S, Landau Z, Gefel D, Green L, Resnitzky P. Pernicious anemia, Hashimoto’s thyroiditis and Sjögren’s in a woman with SLE and autoimmune hemolytic anemia. J Rheumatol. 1989 Feb;16(2):258-9. PMID: 2746580.

10 Guéant JL, Guéant-Rodriguez RM, Alpers DH. Vitamin B12 absorption and malabsorption. Vitam Horm. 2022;119:241-274. doi: 10.1016/bs.vh.2022.01.016. Epub 2022 Mar 1. PMID: 35337622.

11 Quigley EM, Carmichael HA, Watkinson G. Adult celiac disease (celiac sprue), pernicious anemia and IgA deficiency. Case report and review of the relationships between vitamin B12 deficiency, small intestinal mucosal disease and immunoglobulin deficiency. J Clin Gastroenterol. 1986 Jun;8(3 Pt 1):277-81. doi: 10.1097/00004836-198606000-00016. PMID: 3734360.

12 Abraham Z, Rozenbaum M, Glück Z, Feuerman EJ, Lahat N, Kinarty A. Vitiligo, rheumatoid arthritis and pernicious anemia. J Dermatol. 1993 Jul;20(7):418-23. doi: 10.1111/j.1346-8138.1993.tb01310.x. PMID: 8408923.

13 Andrès E, Fothergill H, Mecili M. Efficacy of oral cobalamin (vitamin B12) therapy. Expert Opin Pharmacother. 2010 Feb;11(2):249-56. doi: 10.1517/14656560903456053. PMID: 20088746.

14 Andrès E, Henoun Loukili N, Noel E, Maloisel F, Vinzio S, Kaltenbach G, Caro-Sampara F, Blicklé JF. Effects of oral crystalline cyanocobalamin 1000 μg/d in the treatment of pernicious anemia: An open-label, prospective study in Ten Patients. Curr Ther Res Clin Exp. 2005 Jan;66(1):13-22. doi: 10.1016/j.curtheres.2005.02.001. PMID: 24672108; PMCID: PMC3964566.

15 Thakkar K, Billa G. Treatment of vitamin B12 deficiency-methylcobalamine? Cyancobalamine? Hydroxocobalamin?-clearing the confusion. Eur J Clin Nutr. 2015 Jan;69(1):1-2. doi: 10.1038/ejcn.2014.165. Epub 2014 Aug 13. PMID: 25117994.

16 Bensky MJ, Ayalon-Dangur I, Ayalon-Dangur R, Naamany E, Gafter-Gvili A, Koren G, Shiber S. Comparison of sublingual vs. intramuscular administration of vitamin B12 for the treatment of patients with vitamin B12 deficiency. Drug Deliv Transl Res. 2019 Jun;9(3):625-630. doi: 10.1007/s13346-018-00613-y. PMID: 30632091.

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