Vitamin B12 Deficiency: Signs, Symptoms, And Risk Factors

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Symptoms Of Vitamin B12 Deficiency

The symptoms of vitamin B12 deficiency include chronic anemia, heart disease, skin diseases, sore tongue, numbness, loss of balance, depression, psychosis, dementia, and even infertility. A vegan diet, a history of weight loss surgery, intestinal diseases, heavy drinking, and treatment for stomach acid problems are all risk factors. The elderly and the babies born to vegan mothers are more at risk of vitamin B12 deficiency.

The symptoms of vitamin B12 deficiency are diverse, including both physical and mental symptoms. The physical symptoms include palpitations, incurable fatigue, loss of balance, numbness, tingling, pale skin, and sore and red tongue. The mental symptoms include memory loss, depression, or obsessive compulsive disorder. While the mental symptoms are a direct effect of the lack of vitamin B12, some of the physical symptoms are due to the anemia it causes.

Vitamin B12 Is Essential For Your Nerves And Genes

Vitamin B12 (cobalamin) is one of the 8 essential B vitamins. As it is water soluble, your body cannot store it; so, it needs to be constantly sourced through food. All B vitamins help produce energy in the body by converting carbohydrates from the food into fuel (glucose) and use fat and protein optimally. An important function of vitamin B12 is maintaining healthy nervous system and also the production of the body’s genetic material, DNA and RNA. Vitamin B12 along with vitamin B9 or folic acid help make red blood cells. And along with B9 and B6, B12 controls blood levels of the amino acid homocysteine. A high level of homocysteine can lead to heart diseases.1

Signs And Symptoms Of Vitamin B12 Deficiency

As an adult, you need only 2.4 mcg vitamin B12 daily through your diet. For infants below 1 year, the daily requirement ranges from 0.4 to 0.5 mcg. Pregnant and lactating mothers require 2.6 and 2.8 mcg, respectively.2

The only source of vitamin B12 are foods, mostly from animal sources, and supplements. While vegetarians can get it from dairy products, they still risk not getting enough. However, vegans have a high risk of vitamin B12 deficiency if they do not eat B12-fortified foods and supplements. Deficiency occurs either when you don’t get enough of it through your diet or when your body cannot absorb it effectively. Poor absorption is caused by aging, low stomach acid, chronic digestive disorders like Crohn’s disease or celiac disease, stomach surgeries, and pernicious anemia.

Do note that your liver stores vitamin B12, and if you go vegan or stop eating vitamin B12 foods, your B12 stores can last for 3 to 5 years.3 The symptoms will start showing up after that period. If you think your diet does not include these non-veg, veg, and vegan sources of vitamin B12 or if you have any of the conditions mentioned above, look out for the following signs and symptoms.

1. Memory Loss, Depression, OCD, And Psychosis

The first signs of vitamin B12 deficiency, which could take years to develop, have either to do with your nerves and mental health.4 The list includes depression, memory loss, psychosis, obsessive-compulsive disorder, and dementia.5 The reason behind this is that vitamin B12 helps build the protective myelin sheath around nerve cells. The sheath degenerates with the lack of the vitamin and hinders nerve signal transmission.

2. Anemia, Fatigue, Shortness Of Breath

There are certain blood-related signs that the deficiency could manifest in. But it is highly unlikely that you have hematological symptoms if you already have nervous and mental symptoms. The likelihood of it diminishes further with the severity of the neuropsychiatric symptoms.6

Anemia is a classic vitamin B12 deficiency symptom. Severe anemia could lead to breathing difficulty on exertion, fatigue, as well as symptoms related to congestive heart failure, such as ankle edema, breathing difficulty, frequent urination in the night, etc.7

3. Nausea, Vomiting, Heartburn, And Bloating

Some symptoms of the deficiency involve the digestive tract like nausea, vomiting, heartburn, abdominal bloating and gas, constipation or diarrhea, loss of appetite, and weight loss. An enlarged liver is another symptom.8

4. Skin Lesions, Vitiligo, And Sore Tongue

Any change in the cobalamin content in the body can show on the skin as vitiligo, dermatitis, hyperpigmentation, or acne. Skin lesions, especially the ones not responding to any other treatment, are most likely from cobalamin deficiency.9 Your hair and nail could change, too.

Glossitis or inflammation of the tongue that makes food intake difficult is another symptom of vitamin B12 deficiency.10

Vitamin B12 Is Found Mostly In Animal Sources

Since vitamin B12 cannot be produced in the body, it is essential to include food that supplies it in our diet. Plants don’t make it and the only living things that make vitamin B12 are certain bacteria present in the digestive tract of animals. Hence, it is naturally found in animal products like fish, meat, eggs, milk, milk products, etc. This is one reason why vegans are often deficient in this vitamin; they have to have vitamin B12 supplements or foods fortified with vitamin B12 regularly. Another source of this vitamin B12 is certain nutritional yeast products.11

8 Causes And Risk Factors Vitamin B12 Deficiency

You are at risk for the deficiency if you:

1. Veganism Or Vegetarianism

Who would’ve thought some crucial lifestyle decisions that we take to make our lives better could actually backfire? If you’ve just turned vegan or vegetarian, you might want to be extra vigilant about this deficiency. In fact, it is so common among vegans that at least some people believe the escalation in the number of vitamin B12 deficiency cases is because of the popularity of veganism.

When 40 research studies were analyzed on the prevalence of the deficiency among people, higher deficiency prevalence was found in vegans than in vegetarians. However, all vegetarians should be periodically screened for the deficiency.12

This is primarily because the natural sources of vitamin B12 are animal products. There are many vegetarian products like spirulina (blue-green algae) that are marketed as good sources of vitamin B12 but some researchers have found them to be bogus. They have also found that the process of cooking and storing can, in fact, destroy the vitamin.13

2. Weight-Loss Surgery

Vitamin B12 deficiency is seen very commonly among people who have had bariatric surgery. There are two types of bariatric surgery – gastric bypass where a portion of the stomach is made into a small pouch and attached to the distal segment of the small intestine; and restrictive techniques like gastric binding where a restriction is created in the stomach to limit the food intake of the patient.

The gastric bypass type of surgery often leads to malabsorption of nutrients, one of them being vitamin B12.14 This is because the stomach secretes a protein called gastric intrinsic factor (GIF) which must bind to vitamin B12 to make it absorbed in the small intestine. Gastric bypass decreases the production of GIF as only a small portion of the stomach is available to secrete the protein. This, in turn, leads to poor absorption of B12.

3. Consistent Intake Of Antacids

Proton pump inhibitors or PPIs are often used in the treatment of gastrointestinal disorders like gastroesophageal reflux disease and peptic ulcers. Long-term use of PPIs can inhibit the absorption of vitamin B12 from food. The absorption of vitamin B12 involves peptic enzymes that take apart dietary B12 from dietary proteins, an action performed primarily by pepsin which needs gastric acid to activate it. Since gastric acids are needed to absorb vitamin B12, suppressing these acids may result in vitamin B12 deficiency.15

4. Stomach Or Intestinal Disease

Many stomach and intestinal diseases can affect cobalamin absorption. Small intestine bacterial overgrowth or SIBO is one such that puts you at risk of various conditions like irritable bowel syndrome, celiac disease, chronic diarrhea etc. Vitamin B12 malabsorption is considered one of the complications.16

Equally risky is Crohn’s disease characterized by a damaged ileum, a section of the small intestine responsible for vitamin B12 absorption.17

Atrophic gastritis, or the inflammation of the mucous membrane lining the stomach, can also result in vitamin B12 deficiency.18 It results in the absence of GIF and can lead to an immune system disorder called pernicious anemia.19

5. Heavy Drinking

Vitamin B12 deficiency is associated with alcohol abuse. This is more prominent in heavy drinkers and those with alcoholic liver disease. Interestingly, in the case of alcoholics, there is elevated serum vitamin B12 levels but it doesn’t get metabolized, resulting in a deficiency.20

6. Age Above 50 Years

Studies have shown that the chances of vitamin B12 deficiency increase with age. An estimated 10–15% of people above 60 are found to have this deficiency.21 This is mainly due to the decrease in the stomach acid secretion and the quantity of the digestive enzyme pepsin, resulting in diminished digestion and absorption of vitamin B12.22 Older people with gastrointestinal problems are more susceptible to the deficiency.23

People over 50 years of age may show neurological changes due to vitamin B12 deficiency, resulting in increased cases of nerve and mental disorders among the elderly. Other than this, vitamin B12 deficiency in the elderly have been associated with many health problems like elevated blood levels of homocysteine that could increase their chances of developing heart disease, stroke, and other diseases.24

7. Breastfeeding By A B-12 Deficient Mother

Talking about the age factor, vitamin B12 deficiency is very common in infants born to vegan or vegetarian mothers. A study has shown that the prevalence of the deficiency among infants is about 45%.25

Both unborn and newborn babies have a special need for vitamin B12 and if the mother is a vegetarian or a vegan, this need may not be met either through her diet for the unborn or through her breast milk for the newborn. As a consequence, vitamin B12 deficiency may develop in a breastfed infant within 3–6 months of age affecting its growth severely.26

8. Genetic Factors

The findings of a research published in the journal Nature Genetics indicates that vitamin B12 deficiency could lead to a genetic disease. It also identified a gene involved in the transport of the vitamin to the cells of the body, underscoring the fact that the deficiency could be genetic, too. Various genetic mutations in the body can inhibit the absorption of the vitamin in the body. In fact, in a study conducted on 154 families of suspected hereditary cobalamin malabsorption, 126 families were found to have 1 of the 3 genes – CUBN, AMN, and GIF – mutated.27

Complications From Ignoring The Deficiency

Prolonged vitamin B12 or cobalamin deficiency can lead to many health complications.

  • Pernicious anemia is both a cause and complication of prolonged vitamin B12 deficiency. Pernicious means “deadly” and that gives an idea on what this anemia can do to you in the long run. Anemia due to vitamin B12 deficiency is often called pernicious anemia even if the cause for vitamin B12 deficiency is something else. Pernicious anemia can lead to a host of complications like nerve damage, neurological problems, and gastrointestinal issues. It can also affect the immune system severely.28
  • Depression, especially in the elderly, is linked to cobalamin deficiency. This makes the periodical evaluation of serum vitamin B12 among elderly very important.29
  • Dementia and Alzheimer’s disease are major complications from prolonged vitamin B12 deficiency.30 Elevated homocysteine levels are associated with B vitamin deficiency which can result in critical levels of brain atrophy.31
  • Cardiovascular disease is another major risk associated with vitamin B12 deficiency. While a vegetarian diet is largely considered healthier for the heart than non-vegetarian diet, cobalamin deficiency is found to negate this beneficial effect.32
  • Fertility issues can also be caused by vitamin B12 deficiency. It can cause changes in ovulation and in the development of the ovum. Increased homocysteine levels from the deficiency can also result in fetal loss.33

Could It Be Treated?

There are many ways vitamin B12 deficiency can be treated but it depends on the cause.

If it is diet related, you would be asked to modify your diet to plug the gap in nutrition. Since vitamin B12 sources are largely animal food products, vegans and vegetarians will be advised to go for fortified foods and supplements.

If it is not a diet-related deficiency, it is treated with vitamin B12 injections called hydroxocobalamin. If neurological symptoms are involved, a hematologist will decide the treatment. Further treatment modalities will be decided on the symptoms and their severity.34

Treatments may be life long in vegans whereas, in non-vegans, a vitamin B12 rich diet can take over when the deficiency is taken care of after the initial treatment.

[Next: Top Vegan Sources Of Vitamin B12 You Didn’t Know]

References   [ + ]

1, 2.Vitamin B12. University of Maryland Medical Center.
3.Vitamin B12. The MSD Manual.
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5.Metzler, M. S., M. D. Miller, H. William, M. D. Edwards, and C. Stephen. “Psychiatric Manifestation of Vitamin B-12 Deficiency: An Update.” Jefferson Journal of Psychiatry 9, no. 2 (2011): 8.
6.Rannelli, Luke, Rita Watterson, Rupang Pandya, and Alexander A. Leung. “Vitamin B 12 deficiency with combined hematological and neuropsychiatric derangements: a case report.” Journal of medical case reports 8, no. 1 (2014): 277.
7.Briani, Chiara, Chiara Dalla Torre, Valentina Citton, Renzo Manara, Sara Pompanin, Gianni Binotto, and Fausto Adami. “Cobalamin deficiency: clinical picture and radiological findings.” Nutrients 5, no. 11 (2013): 4521-4539.
8.What Are The Signs And Symptoms Of Pernicious Anemia. NIH.
9.Kannan, Rajendran, and Matthew Joo Ming Ng. “Cutaneous lesions and vitamin B12 deficiency An often-forgotten link.” Canadian Family Physician 54, no. 4 (2008): 529-532.
10.Brescoll, Jennifer, and Steven Daveluy. “A review of vitamin B12 in dermatology.” American journal of clinical dermatology 16, no. 1 (2015): 27-33.
11.Vitamin B12. NIH.
12, 25.Pawlak, Roman, S. E. Lester, and T. Babatunde. “The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature.” European journal of clinical nutrition 68, no. 5 (2014): 541-548.
13, 23, 24.Preventing Vitamin B12 Deficiency Among Vegetarians, Vegans And The Elderly. ACS.
14.John, Seeniann, and Carl Hoegerl. “Nutritional deficiencies after gastric bypass surgery.” The Journal of the American Osteopathic Association 109, no. 11 (2009): 601-604.
15.Heidelbaugh, Joel J. “Proton pump inhibitors and risk of vitamin and mineral deficiency: evidence and clinical implications.” Therapeutic advances in drug safety 4, no. 3 (2013): 125-133.
16.Dukowicz, Andrew C., Brian E. Lacy, and Gary M. Levine. “Small intestinal bacterial overgrowth: a comprehensive review.” Gastroenterol Hepatol (NY) 3, no. 2 (2007): 112-22.
17.Ahmed, M., and H. R. Jenkins. “Vitamin B-12 in Crohn’s disease patients with small bowel surgery.” Archives of disease in childhood 89, no. 3 (2004): 293-293.
18.Meyniel, D., J. Petit, F. Bodin, R. Poupon, and F. Darnis. “Vitamin B12 deficiency in chronic atrophic gastritis. 3 cases (author’s transl).” La Nouvelle presse medicale 10, no. 27 (1981): 2281-2284.
19.Vitamin B12 Deficiency. Harvard Health Publications.
20, 21.Fragasso, Alberto. “Vitamin B12 deficiency in alcoholics.” In Alcohol, nutrition, and health consequences, pp. 131-134. Humana Press, 2013.
22.Vitamin B12 In Vegetarian Diets. Academy Of Nutrition And Diatetics.
26.Vitamin B12 In Vegetarian Diets. Academy Of Nutrition And Diatetics.
27.Tanner, Stephan M., Amy C. Sturm, Elizabeth C. Baack, Sandya Liyanarachchi, and Albert de la Chapelle. “Inherited cobalamin malabsorption. Mutations in three genes reveal functional and ethnic patterns.” Orphanet journal of rare diseases 7, no. 1 (2012): 56.
28.What Is Pernicious Anemia. NIH.
29.Miskulin, Maja, Marija Kristic, and Jelena Vlahovic. “Vitamin B12 deficiency and depression in elderly: cross-sectional study in Eastern Croatia.” Journal of Health Sciences 4, no. 3 (2014).
30.Moore, Eileen, Alastair Mander, David Ames, Ross Carne, Kerrie Sanders, and David Watters. “Cognitive impairment and vitamin B12: a review.” International psychogeriatrics 24, no. 04 (2012): 541-556. Jager, Celeste A. “Critical levels of brain atrophy associated with homocysteine and cognitive decline.” Neurobiology of aging 35 (2014): S35-S39.
32.Pawlak, Roman. “Is Vitamin B 12 Deficiency a Risk Factor for Cardiovascular Disease in Vegetarians?.” American journal of preventive medicine 48, no. 6 (2015): e11-e26.
33.Bennett, Michael. “Vitamin B12 deficiency, infertility and recurrent fetal loss.” The Journal of reproductive medicine 46, no. 3 (2001): 209-212.
34.Treating Vitamin B12 Deficiency Anemia. NHS.

Disclaimer: The content is purely informative and educational in nature and should not be construed as medical advice. Please use the content only in consultation with an appropriate certified medical or healthcare professional.

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