U.S. flag

An official website of the United States government

Here’s how you know
Here’s how you know

**Official websites use .gov**
A **.gov** website belongs to an official government organization in the United States.

**Secure .gov websites use HTTPS**
A **lock** ( A locked padlock) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Search Query:
			MAIN MENU

																				
              Health Topics
								All Health Topics A-Z
					
													
		

		Asthma


				

															Heart-Healthy Living


				

															High Blood Pressure


				

															Sickle Cell Disease


				

															Sleep Apnea


				

															Information & Resources on COVID-19
																				
              Health Education
								Education Programs and Initiatives
					
													
		

		The Heart Truth®


				

															Learn More Breathe Better®


				

															Blood Diseases and Disorders Education Program


				

															Publications and Resources
																				
              The Science
								Research Focus Areas
					
													
		

		Blood Disorders and Blood Safety


				

															Sleep Science and Sleep Disorders


				

															Lung Diseases


				

															Health Disparities and Inequities


				

															Heart and Vascular Diseases


				

															Precision Medicine Activities


				

															Obesity, Nutrition, and Physical Activity


				

															Population and Epidemiology Studies


				

															Women’s Health


				

															Research Topics


				

															Clinical Trials


				

															All Science A-Z
																				
              Grants and Training
								Grants and Training Home


				

															Policies and Guidelines


				

															Funding Opportunities and Contacts


				

															Training and Career Development
																				
              News and Events
								News and Events Home
					
													
		

		Email Alerts


				

															All News
					
													
		

		NHLBI News


				

															NHLBI in the Press


				

															Research Features


				

															All Events
					
													
		

		Past Events


				

															Upcoming Events
																				
              About NHLBI
								About NHLBI Home
					
													
		

		Mission and Strategic Vision


				

															Leadership


				

															Divisions, Offices and Centers


				

															Advisory Committees


				

															Budget and Legislative Information


				

															Jobs and Working at the NHLBI


				

															Contact and FAQs


				

															NIH Sleep Research Plan
						
						HOME
		Search Text: Anemia
HomeHealth Topics< Back ToAnemiaVitamin B12–Deficiency Anemia

0
  Anemia
        MENU

    HomeHealth Topics< Back ToAnemiaVitamin B12–Deficiency Anemia

  What Is Anemia?
                                                  
                          Symptoms
                                                  
                          Diagnosis
                                                  
                          Causes and Risk Factors
                                                  
                          Treatment and Management
                                                  
                          Anemia in Pregnancy
                                                  
                                                                                Types of Anemia
                                                                      Iron-Deficiency Anemia
                                                  
                          Vitamin B12–Deficiency Anemia
                                                  
                          Hemolytic Anemia
                                                  
                          Aplastic Anemia
MORE INFORMATION
                        Find a clinical trial
                        Fact sheets and handouts
                            Research
    
          Anemia
AnemiaVitamin B12–Deficiency Anemia

Language switcherEnglishEspañol
IN THIS ARTICLE
              View More
        View Less
What is vitamin B12–deficiency anemia?

            What it is
      
            Vitamin B12–deficiency anemia, also known as cobalamin deficiency, is a condition that develops when your body can't make enough healthy red blood cells because it doesn't have enough vitamin B12. Your body needs vitamin B12 to make healthy red blood cells, white blood cells, and platelets. Since your body doesn’t make vitamin B12, you have to get it from the foods you eat or from supplements.

You can get vitamin B12 deficiency if you can’t absorb vitamin B12 due to problems with your gut or if you have pernicious anemia, which makes it difficult to absorb vitamin B12 from your intestines. Without enough vitamin B12, blood cells do not form properly inside your bone marrow, the sponge-like tissue within your bones. These blood cells die sooner than normal, leading to anemia.

          
What are the symptoms of vitamin B12–deficiency anemia?

            Symptoms
      
            If you have vitamin B12–deficiency anemia, you may have the typical symptoms of anemia at first, such as fatigue, paleness, shortness of breath, headaches, or dizziness. If left untreated, you may start to notice brain and nervous system symptoms. This is because vitamin B12 is also needed for your brain and your nerves to work properly.

Your symptoms may include:

Tingling feelings or pain
	Trouble walking
	Uncontrollable muscle movements
	Confusion, slower thinking, forgetfulness, and memory loss
	Mood or mental changes**,** such as depression or irritability
	Problems with smell or taste
	Vision problems
	Diarrhea and weight loss
	Glossitis, which is a painful, smooth, red tongue

          
What causes vitamin B12–deficiency anemia?

            Causes
      
            You can develop vitamin B12–deficiency anemia if you do not eat enough food with vitamin B12, such as if you follow a strict vegetarian or vegan diet. But this is rare. In the United States, vitamin B12–deficiency anemia is most often due to other risk factors.

You can develop vitamin B12 deficiency for the following reasons:

**Lack of intrinsic factor:** Intrinsic factor is a protein made in the stomach, which helps the body absorb vitamin B12. People who have pernicious anemia do not produce intrinsic factor. Pernicious anemia is more common in people with northern European or African ancestry. You may develop vitamin B12–deficiency anemia if your body is not able to absorb enough vitamin B12 from the foods you eat. Older adults are more likely to have digestive problems that make it harder to absorb vitamin B12.
	**Lifestyle habits:** Drinking too much alcohol can make it harder for your body to absorb vitamin B12. For men this is more than two drinks in a day. For women, it’s more than one drink in a day.
	**Medicines:** Taking certain medicines can make it harder for your body to absorb vitamin B12 over time. These include some heartburn medicines and metformin to treat diabetes.
	**Medical conditions:** Some medical conditions can raise your risk of vitamin B12–deficiency anemia. These include:
	**Autoimmune diseases,** such as celiac disease, type 1 diabetes, and thyroid disease**Chronic pancreatic disease**
		**Genetic conditions,** such as Imerslund-Gräsbeck syndrome, inherited intrinsic factor deficiency, and inherited transcobalamin deficiency
		**Intestinal and digestive conditions,** such as ulcerative colitis, Crohn’s disease, and Helicobacter pylori infection
		**Vitiligo**
	**Stomach surgery:** Surgery on your stomach or intestines, such as weight-loss surgery or gastrectomy, can make it harder for your body to absorb vitamin B12.

          
How do you prevent vitamin B12 deficiency?

            Prevention
      
            If you are otherwise healthy, maintaining a normal diet enriched in vitamin B12 is important.

Foods that are good sources of vitamin B12 include:

Lean red meat and chicken
	Fish, such as catfish and salmon; and seafood, such as clams and oysters
	Milk, yogurt, cheese, and fortified vegan milk substitutes
	Fortified cereals
	Eggs

          
How much vitamin B12 do you need each day?

            Vitamin B12 recommendations
      
            The recommended daily amounts of vitamin B12 depend on your age, your sex, and whether you are pregnant or breastfeeding. Your healthcare provider can look at your medical history to help determine how much vitamin B12 you need each day.

**Recommended daily vitamin B12 intake for children and adults**

**Recommended Daily Amounts of Vitamin B12, in micrograms (mcg)****Age**
			**Male or Female**
			**Pregnancy**
			**Breastfeeding**1–3 years
			0.9 mcg4–8 years
			1.2 mcg9–13 years
			1.8 mcg14–18 years
			2.4 mcg
			2.6 mcg
			2.8 mcg19–50 years
			2.4 mcg
			2.6 mcg
			2.8 mcg51+ years
			2.4 mcg (mostly from fortified foods or a supplement)

          
How is vitamin B12–deficiency anemia diagnosed?

            Diagnosis
      
            To screen for vitamin B12–deficiency anemia, your healthcare provider may order blood tests to see whether you have low hemoglobin or vitamin B12 levels.

**Healthy and Abnormal Blood Levels in Adults****Hemoglobin, g/dL**
			Normal
			Men: 13 or higher

			Women: 12 or higherAnemia
			Men: 12 or lower

			Women: 11 or lower**Vitamin B12, pg/mL**
			Normal
			400 or higherVitamin B12-deficiency
			200 or lower (although levels may be normal in some cases)**Tests to screen for vitamin B12-deficiency anemia.** A complete blood count measures hemoglobin. Another blood test measures vitamin B12 levels in the blood. You may still have the condition even if your vitamin B12 levels are normal.

          
How is vitamin B12–deficiency anemia treated?

            Treatments
      
            If your doctor diagnoses you with vitamin B12–deficiency anemia, your treatment will depend on the cause and seriousness of your condition. Some people need lifelong treatment.

Different therapies can be used to treat anemia.

**Vitamin B12 medicine can be prescribed by your provider** for you to take by mouth or as a nose spray or a shot. These supplements can help increase the levels of vitamin B12 in your body. For serious vitamin B12–deficiency anemia, your doctor may recommend vitamin B12 shots until your levels are healthy.**Blood transfusion****s** to treat serious vitamin B12–deficiency anemia in combination with vitamin B12 treatment.Your care provider may also recommend you make some changes to your eating habits to help increase the amount of vitamin B12 in your diet.

Some symptoms may take months to improve, depending on how serious they are. Some symptoms related to the brain or the nerves, such as numbness and tingling, may not go away even with treatment.

          
What happens if vitamin B12–deficiency anemia is not treated?

            What happens if not treated
      
            Vitamin B12–deficiency may cause serious complications, such as bleeding, infections, and problems with your brain or nerves that may be permanent. Babies born to mothers who have vitamin B12–deficiency may have developmental delays and birth defects of the brain and spinal cord.
Book traversal links for Vitamin B12–Deficiency Anemia
      Previous
                    Iron-Deficiency Anemia
                    Next
                    Hemolytic Anemia
  Last updated on March 24, 2022 Back To Top Link
  

        

        Back to top
  Web Policies & Notices
  

        

              Accessibility
                      No FEAR Act Data
                      Privacy Policy
                      Freedom of Information Act (FOIA)
                      HHS Vulnerability Disclosure
    
          Related Government Websites
  

        

              Health and Human Services
                      National Institutes of Health
                      Office of the Inspector General
                      USA.gov
    
          Stay Connected
    
      
            chat bubblesLive ChatLive Chat with us, Monday through Friday, 8:30 a.m. to 5:00 p.m. EST.envelopeGet Email AlertsReceive automatic alerts about NHLBI related news and highlights from across the Institute.
  Footer Bottom
  

        



Contact Us
                            Site Index
                            Jobs