What Are The Symptoms Of Vitamin B12 Deficiency?

Nutrients are crucial to the general health of the human body. When a deficiency develops, a person is at risk of malnutrition.

In turn, this can turn into a bigger problem. The result may be serious complications due to the lack of essential nutrients that help cells perform their functions.

Vitamin B12 is considered a crucial nutrient that every person should ensure they get enough of. The vitamin plays several roles in the human body.

A deficiency in vitamin B12 can cause weakness and other adverse effects. In some cases, complications from a vitamin B12 deficiency can also lead to severe problems.

The National Health and Nutrition Examination Survey estimated that 3.2% of adults over age 50 have a seriously low B12 level, and up to 20% may have a borderline vitamin B12 deficiency.

We look at what it means to have a vitamin B deficiency. We will also consider the role of vitamin B12 in the body, and consider what signs to look out for. The post looks at some effective ways that people can increase vitamin B12 levels in cases where a deficiency does develop.

What Is Vitamin B12 Deficiency?

Vitamin B12 is an important nutrient. It plays a role in:

  • Nerve function

  • Blood cells

  • DNA production

In some cases, a person may not obtain enough vitamin B12. This can lead to vitamin B12 deficiency.

Vitamin B12 deficiency means the circulating levels of the vitamin in the body are lower than what is considered normal or healthy. This is regarded as a relatively serious problem.

When there is a deficiency in vitamin B12, the functions regulated by the vitamin will be reduced. In turn, a person may find that they start to experience unpleasant symptoms. If left untreated, the condition can become more serious.

Who is at risk of vitamin B12 deficiency?

Vitamin B12 deficiency is not as common as deficiencies of some other vitamins. Still, it does pose a problem. The leading group at risk tend to be vegans. However, many other people also fail to get enough vitamin B12 in their diet.

One study1 found that less than 3% of adults under the age of 39 have a vitamin B12 deficiency. The prevalence increases with age, however. About 4% of adults between 40 and 59 years of age have a deficiency in vitamin B12. Among people over 70 years, the prevalence rises to over 6%.

Even children seem to be at risk of vitamin B12 deficiency. The prevalence may be just under 1% in children and adolescents. Among younger children – particularly those under four years of age – the prevalent is estimated to fall only under 3%.

People need to realize their risk of vitamin B12 deficiency. This starts with a thorough view of the causes of this problem.

Risk factors for vitamin B12 deficiency include:

  • The elderly

  • Those who’ve had surgery that removes the part of the bowel that absorbs B12

  • People following a strict vegan diet

  • Those taking long-term antacid drugs for heartburn which reduce acid production in the stomach.

Some conditions that have been linked to vitamin B12 deficiency include:

  • Atrophic gastritis

  • Celiac disease

  • Pernicious anemia

  • Crohn’s disease

  • Immune system disorders

Following a vegan diet is also a common cause of Vitamin B12 deficiency. This is because a vegan diet removes many foods that contain vitamin B12.

Many foods with this vitamin are derived from animals. Vegans exclude any animal-derived foods in their diet. Some of these foods include eggs, milk, cheese, and meat.

One study2 looked at the prevalence of vitamin B12 deficiency in vegetarians and vegans. The study considered previous surveys and clinical trials that were conducted. The results were quite surprising.

In some studies, a prevalence of up to 86.5% was noted. There was a prevalent vitamin B12 that reached up to 39% among groups of pregnant women. In infants, the deficiency prevalence reached up to 45%.

What Role Does Vitamin B12 Have In The Body?

Vitamin B12 is one of the many vitamins that are essential for a healthy body and one of the eight Vitamin B’s out there.

Vitamin B12 is also known as cobalamin, and it is responsible for many vital body functions3. It keeps your cells fed and happy, and without it, your cells would be starving and, with time, become unable to do their job.

All cells in the human body depend on the presence of vitamin B12.

Next is the heart. Vitamin B12 has a role in removing a dangerous protein known as homocysteine from the blood. Homocysteine leads to an inflammatory response in the body. The inflammation can negatively affect the heart. Homocysteine has also been shown to cause damage to blood vessels.

Apparently, by removing this protein, the Vitamin B12 also helps to prevent osteoporosis!

It also protects your brain, prevents Alzheimer’s, controls your mood, and prevents any mood swings.

Vitamin B12 also plays a part in DNA production. DNA forms as the basis for the body and helps with the regulation of many vital functions. When there is a deficiency in Vitamin B12, problems with the production of DNA can occur. DNA is also considered genetic material that forms part of every cell in the body.

Vitamin B12 is also a critical element in blood cell production. While on the subject of the vitamin’s role in blood production, it is important to note that vitamin B12 protects a person against a specific form of anemia. The condition is called megaloblastic anemia.

The anemia causes tiredness and weakness in affected people. This is different from macrocytic anemia. Sometimes, the condition is referred to as vitamin B deficiency anemia. Other vitamin deficiencies can also cause similar problems, such as a lack of enough folate or pantothenic acid.

Hydrochloric acid causes vitamin B12 to be separated from a protein in the stomach. The protein is found in foods that contain vitamin B12. The stomach produces a protein known as intrinsic factor. The separated vitamin B12 then combines with this specific protein. It is then sent throughout the body to perform its functions in cells.

It should be noted that pernicious anemia is known to affect intrinsic factor production adversely. When there is a lack of this protein in the stomach, vitamin B12 absorption can be negatively affected.

What Are The Symptoms Of Vitamin B12 Deficiency?

Vitamin B12 deficiency can sometimes lead to severe complications. This is why people need to recognize symptoms that may indicate a deficiency in this particular vitamin. Different symptoms can develop. This is due to the multiple functions that vitamin B12 has in the body.

A critical complication of vitamin B12 deficiency would be anemia. For this reason, we must mention the characteristic anemia symptoms5. Various symptoms may signal anemia.

The condition leads to a lack of red blood cells in the body. This causes problems with the delivery of essential nutrients to cells and tissue in the body. Blood also carries oxygen to all areas of the body. Symptoms associated with anemia can include:

Some people can also experience sudden weight loss with no apparent explanation. Many conditions can cause sudden weight loss. Vitamin B12 deficiency is just one of these – at any rate, unexplained weight loss should always be considered a cause for concern.

In addition, characteristic symptoms for Vitamin B12 deficiency also occur. Vitamin B12 deficiency symptoms can help a doctor with the diagnosis of the condition. The patient will be asked about how they feel and any specific symptoms they experience.

The anemia symptoms, along with signs related to vitamin B12 deficiency, helps with the diagnosis. The doctor may ask the patient to undergo certain tests to make sure that their suspicion is correct.

Some of the symptoms that a patient may present when they suffer a deficiency in vitamin B12 include:

  • Mood swings

  • Symptoms generally associated with depression

  • Dementia and other memory-related problems can occur

  • Irritability with no obvious cause

  • Strange sensations, numbness, and tingling in the hands, legs, or feet

  • There could be certain vision changes

  • Some people experience a sore tongue (known as glossitis)

  • Mouth ulcers can occur in some cases

  • There are some people who may also experience a yellow-colored skin.

People should also ensure they can recognize these symptoms. Early detection of vitamin B12 deficiency is important. The diagnosis of vitamin B12 deficiency is based on blood tests.

There are effective ways to restore normal levels of vitamin B12. When this is done before complications develop, a patient might be able to prevent the occurrence of nerve damage. The nerve damage (neuropathy) that may occur with a vitamin B12 deficiency can be permanent. This can lead to long-term complications due to the insufficient intake of this particular vitamin.

How Much Vitamin B12 Should You Get?

The number of vitamin B12 needed to depend on age. Some people need more vitamin B12 than others. This is often the case in women who are pregnant.

Some research indicates that low maternal vitamin B12 status has been associated with an increased risk of neural tube defects (NTD). When breastfeeding, a woman will also need a little more vitamin B12.

A person must ensure they get an appropriate amount of vitamin B12 each day. This value should be based on the recommended intake. Too much or too little vitamin B12 can be harmful.

Adults over the age of 18 are advised to obtain about 2.4mcg of vitamin B12 from diet and supplements each day. This is enough to effectively support the functions in the body that relies on vitamin B12.

Similar intake guidelines of 2.4mcg vitamin B12 per day are advised for adolescents and teens between the age of 14 and 18.

Younger children do not need as much vitamin B12. The recommendations for children range from 0.4mcg for newborn babies, up to 1.8mcg for children between nine and 13 years of age.

Women who are pregnant are advised to increase their intake of vitamin B12 daily. The recommended vitamin B12 intake for pregnant women is 2.6mcg per day. When breastfeeding, the recommended daily intake increases further to 2.8mcg per day.

How Can You Increase Vitamin B12?

Vitamin B12 deficiency is a real concern. While the prevalence of the deficiency is not at an alarming rate, there are still millions of people who do not get enough vitamin B12 each day. This causes these individuals to be at risk of serious complications.

The body’s DNA even depends on vitamin B12. With this in mind, people who are deficient in vitamin should consider how they can increase their intake of vitamin B12.

There are different ways to increase a person’s intake of vitamin B12. The specific method most appropriate sometimes depends on the severity of the deficiency.

When there is a serious deficiency of vitamin B12, then medical treatment might be needed. This can help to restore adequate levels of the vitamin faster and more effectively. A pharmaceutical grade vitamin B12 supplement will be administered to a patient in such a case.

In most cases, however, there are many at-home strategies that people can take advantage of to increase the level of bioavailable vitamin B12 in their bodies.

We will consider some effective strategies that people should consider to increase their intake of vitamin B12 below.

Increasing Vitamin B12 Through Diet

This one can be somewhat difficult for vegans, but it is possible for most people. A person just needs to sit down and plan a little in order to ensure they get enough vitamin B12 from their diet.

Obtaining the vitamin through diet is the preferred method of assuring an adequate level of vitamin B12 in the body.

Several foods are high in vitamin B12. Including more of these foods in a person’s diet can help to balance levels of the vitamin in their body.

When it comes to diet, it is critical to note that plant-based foods do not include vitamin B12. Thus, people following a plant-based diet will need to shop smart to increase their intake of the vitamin. The best food sources of vitamin B12 include:

  • Liver beef

  • Clams

  • Fish

  • Poultry

  • Milk and other dairy products

  • Eggs

People who do not eat animal products still have options to choose from. There are several foods on the market that are fortified with certain nutrients. Many of these foods will contain added vitamin B12.

Breakfast cereals are often fortified with vitamin B12. Many other vitamins may be included in these cereals too.

When buying fortified food, it is important to consider how much vitamin B12 it contains. There should be enough to provide benefits to the body.

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Supplementing With Vitamin B12

Another option to increase vitamin B12 is to use a supplement. There are several useful supplements on the market. Many multi-vitamin supplements will contain vitamin B12.

vitamins for energy

These supplements can be exceptionally useful for vegans, as fortified foods can sometimes be limiting.

A vitamin B12 supplement is often also advised for older people. This is because there is often a reduced level of hydrochloric acid in an older person’s stomach. This adversely affects the body’s ability to absorb vitamin B12 effectively.

People with a severe vitamin B12 deficiency might need a pharmaceutical-grade supplement. These supplements are only available through a prescription from a licensed healthcare provider.

The vitamin B12 is generally delivered as a shot in these cases. The doctor can usually administer the shot to the patient. There is also a nasal gel that can sometimes be provided to a patient. These gels also help to increase vitamin B12 levels.

These shots will generally contain a higher level of vitamin B12 compared to regular supplements. The prescription form is only given when medical treatment for vitamin B12 deficiency is needed.

A doctor will usually need to perform a test on a patient first. The patient may present with symptoms associated with vitamin B12 deficiency. When this is suspected, the doctor will ask for a serum vitamin B12 test to be conducted on the patient. When the test comes back with a significantly low level of vitamin B12, then a prescription grade of the supplement may be used.


People who are suffering from some sort of immune system disorder, Pernicious anemia, Crohn’s disease, or celiac disease, should consider their vitamin B12 status. The same factor applies to people on a vegan diet.

People should learn about the symptoms. This would allow them to recognize a vitamin B12 deficiency. Changing eating habits can help a person increase vitamin B12 levels.

In some cases, taking a supplement can also be helpful. A vitamin B12 shot is another option to consider. This helps to prevent the complications that have been associated with a vitamin B12 deficiency. It also ensures a person can benefit from this vitamin.

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  1. The American Journal of Clinical Nutrition. (2008) How common is vitamin B-12 deficiency? [online] Available at: https://academic.oup.com/ajcn/article/89/2/693S/4596795
  2.  European Journal of Clinical Nutrition. (2014) The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of the literature. [online] Available at: https://www.nature.com/articles/ejcn201446
  3.  Global Healing. (2015) 7 Important Functions of Vitamin B12. [online] Available at: https://www.globalhealingcenter.com/natural-health/7-functions-of-vitamin-b12/
  4.  African Journal of Medicine and Medical Sciences. (2014) Plasma homocysteine, B vitamins, and bone mineral density in osteoporosis: a possible risk for bone fracture. [online] Available at: https://www.ncbi.nlm.nih.gov/pubmed/25335377

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