Vitamin B12 Deficiency: Signs, Symptoms, Complications, And Treatments

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Vitamin B12 Deficiency

Vitamin B12 is made by certain bacteria in animal guts and its deficiency can result in a host of health issues from chronic anemia and psychological problems like depression to cardiovascular diseases and even fertility issues. The symptoms of a deficiency can be broadly classified into neuropsychiatric, hematological, gastrointestinal, and cutaneous symptoms. You are at a risk for vitamin B12 deficiency if you are vegan, had a weight loss surgery, has intestinal diseases, are on acid-reducing drugs, or drink heavily. The elderly and the babies born to vegan mothers are more at risk for vitamin B12 deficiency. Treatment depends on the cause and the severity of the symptoms.

We all know someone who has vitamin B12 deficiency, a deficiency that’s hogging the limelight these days. It is one of the eight essential B vitamins and is also called cobalamin because it contains the mineral cobalt. Vitamin B12 is water soluble which means human bodies cannot store this vitamin; it needs to be constantly sourced through food.

Why This Vitamin Is Important

Just to understand why this vitamin or its deficiency is talked about so much, we need to know its properties or what it does to the body.

All B vitamins help produce energy in the body by converting food (carbohydrates) 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 with vitamin B9 or folic acid help make red blood cells while vitamins B12 and B9 with B6 control blood levels of the amino acid homocysteine. A high level of homocysteine can lead to heart diseases.1

Where Do We Get Vitamin B12 From?

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 the vitamin regularly. Another source of this vitamin is certain nutritional yeast products.2

How Much Vitamin B12 Should You Have Every Day?

Going by the advice of the Food & Nutrition Board, the recommended daily intake of vitamin B12 ranges from 0.5-3.0 ug. For infants from 0-12 months, it ranges from 0.4-0.5 ug. Pregnant and lactating individuals require +1.0 ug.3

Are You At Risk For Vitamin B12 Deficiency?

You are at risk for the deficiency if you:

Are Vegan/Vegetarian

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 among vegetarians. However, vegetarians, regardless of the type of vegetarianism they follow, should be periodically screened for the deficiency.4

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.5

Have Had 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. Bariatric surgery often leads to malabsorption of nutrients, one of them being vitamin B12.6

Have Been On Acid-Reducing Drugs

Proton pump inhibitors or PPIs are often used in the treatment of gastrointestinal disorders like gastroesophageal reflux disease, peptic ulcers, etc. 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.7

You Have Any 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.8 Equally risky is Crohn’s disease characterized by a damaged ileum, a section of the small intestine responsible for vitamin B12 absorption.9

Atrophic gastritis is the inflammation of stomach mucosa that can also result in vitamin B12 deficiency.10 Atrophic gastritis results in the absence of intrinsic factor that can lead to an immune system disorder called pernicious anemia. Intrinsic factor is a protein secreted by the stomach lining that carries vitamin B12 to the intestines to be absorbed.11

You Drink Heavily

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.12

Is Age A Factor?

Yes. Studies have shown that the chances of vitamin B12 deficiency increase with age. An estimated 10-15 percent of people above the age of 60 are found to have this deficiency.13 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 B12.14 Older people with gastrointestinal problems are more susceptible to the deficiency.15

People over 50 years of age may show neurological changes due to vitamin B12 deficiency resulting in increased cases of neuropsychiatric disorders among the elderly.16 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.17

Infants Are At Risk, Too

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 percent.18 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.19

Could It Be Genetic?

You would be surprised to hear this but the deficiency of vitamin B12 could be genetic, too. The findings of a research published in the journal Nature Genetics indicates that the research team discovered a new genetic disease due to vitamin B12 deficiency and 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. Inherited malabsorption of cobalamin or Cbl is a widely studied topic. In a study conducted on 154 families of suspected hereditary Cbl malabsorption, 126 families were found to have one of the three genes–CUBN, AMN and GIF–mutated.20

Signs And Symptoms Of Vitamin B12 Deficiency

If you listen to your body, it sends out many vital signs before the deficiency becomes serious. The symptoms of vitamin B12 deficiency can be categorized into neuropsychiatric, gastrointestinal, cutaneous, and hematologic. Here are the symptoms in detail.

Neuropsychiatric Symptoms

Did you know vitamin B12 could take years to develop during which the patients may not show any symptoms at all?21 And the fact is, when they actually begin to show symptoms, the first few could be hematological or neuropsychiatric in nature. In fact, a host of neuropsychiatric disorders has been found to be associated with the deficiency of this vitamin including depression, memory loss, psychosis, obsessive-compulsive disorder, and dementia.22

Hematological Signs

There are certain hematological signs that the deficiency could manifest in. But it is highly unlikely that you have hematological symptoms if you already have neuropsychiatric symptoms and the likelihood of it diminishes further with the severity of the neuropsychiatric symptoms.23

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.24

Gastrointestinal Symptoms

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.25

Cutaneous Symptoms

Any change in the cobalamin content in the body can show on the skin as vitiligo, dermatitis, hyperpigmentation or acne. 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.26

Skin lesions, especially the ones not responding to any other treatment, are most likely from cobalamin deficiency.27

Some Complications You Could Expect 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
  • Cobalamin deficiency can lead to psychological issues like depression, especially in the elderly. This makes the periodical evaluation of serum vitamin B12 among elderly very important.29
  • Another major complication from prolonged vitamin B12 deficiency is the cognitive impairment resulting in neurodegenerative diseases like dementia and Alzheimer’s disease.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. A vegetarian diet is largely considered healthier than non-vegetarian diet when it comes to heart health. But cobalamin deficiency is found to negate this beneficial effect of a vegetarian diet.32
  • It can also lead to a host of fertility issues. 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.35

References   [ + ]

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