Exploring the Benefits of Vitamin B12

September 20, 2023
4 mins

Many people take multivitamins daily, but not everyone understands why specific vitamins are so important. Of course, certain vitamins are the exception. Vitamin C, for example, gets tons of attention and is widely known to help support immunity. But what about some lesser-known vitamins like vitamin B12? 

Vitamin B12 is vital to your health, yet many people aren’t aware of its properties. 

Vitamin B12 (also known as cobalamin) is a vitamin that comes from animal products. Research shows that nearly 6% of adults under 60 and 20% of those over 60 are deficient in this essential vitamin. In other words, millions of people simply aren’t getting enough B12. This deficiency can cause a variety of symptoms – including less energy throughout the day. 

Below is a detailed look at vitamin B12, its functions within the body, and some lesser-known benefits. You’ll also find ways to integrate B12 into your diet for better health.

Online primary care, right from home.

Speak to board-certified doctors and nurses across the screen.

Get Started

What are the Functions of B12 in the Body?

The compounds within our body tend to have multiple functions. Take protein as a prime example. This essential nutrient is a critical component in muscle tissue, enzymes, and regulatory compounds. 

As stated earlier, vitamin B12 is necessary for various bodily processes. Below is a closer look at the many functions of B12 within the body. 

Nervous system

The nervous system is the body system that consists of the brain, spinal cord, and all of the nerves that stem out to the rest of the body. The nervous system is the processor and control center that regulates most of the body’s actions and interprets bodily sensations. Some of its primary “duties” include sending signals to beat the heart, coordinating muscles to allow you to walk, and even helping you to think.

The importance of proper vitamin B12 levels on the nervous system is exemplified in this case study. In the study, an otherwise healthy 21-year-old male suffered from a high degree of prolonged B12 deficiency. The individual had a lack of sensation in his lower legs, difficulty concentrating, and — upon imaging — severe changes to his brain. 

The biology behind the neurological components of these symptoms had to do with B12’s role in producing the myelin sheath. The myelin sheath functions similarly to the outer coating on an electrical wire. It helps insulate nerve cells and allows them to send signals quickly. A severe deficiency in B12 can result in a decline in neurological functioning. 


Blood is another vital tissue of the body. It’s responsible for transporting vital oxygen to your cells. There are many different components of blood, and B12 plays a vital role in ensuring your blood is functioning as it should. 

One way B12 impacts the blood is through helping in the production of red blood cells. Red blood cells are the part of your blood that carries most of the oxygen through the body. When an individual has a B12 deficiency, it can decrease the number of red blood cells produced. This can contribute to anemia – a condition characterized by a deficiency of red blood cells or a low level of hemoglobin in the blood. 

With fewer red blood cells, the body cannot oxygenate properly, resulting in symptoms such as lethargy, diminished physical and cognitive performance, and even hair loss

Another way that B12 impacts the blood is by converting homocysteine to methionine. While this may sound complicated, it’s actually quite simple. In layman’s terms, B12 is responsible for converting one protein into another.

When B12 isn’t present, this conversion doesn’t occur, which results in a buildup of homocysteine. This buildup is detrimental to the cardiovascular system and can increase the risk of cardiovascular complications such as stroke, blood clots, and more. 


DNA can be thought of as the blueprint or “road map” for how each cell functions. Because DNA plays such a fundamental role in your body, it’s crucial to ensure it works optimally. 

One aspect of B12 that many people don’t know about is its role in DNA synthesis and regulation. Converting homocysteine to methionine also plays a vital role in producing the nucleotide known as cysteine, a component of DNA. In other words, the body needs to create nucleotides for DNA replication to occur, and B12 helps to do just that. 

What are the Risk Factors for B12 Deficiency?

Many people believe vitamin deficiencies occur solely as the result of poor dietary choices. But, the reality is that deficiencies can occur in anyone, even people with generally healthy diets. 

A vitamin B12 deficiency can result from genetics, diet, an inability to absorb the compound, and even certain medications. Keep reading to learn about potential risk factors that can increase your chances of developing a B12 deficiency. 


The foods you eat (and don’t eat) can greatly influence your likelihood of developing a B12 deficiency. While vegetarian and vegan diets are largely considered healthy, people who follow these diets have a greater risk of being deficient in B12.

The main reason behind this is that B12 is only naturally found in animal products – such as dairy products, beef and beef liver, poultry, and clams. Both vegetarian and vegan diets exclude animal-based foods – and as a result – people who follow these diets can develop a B12 deficiency.

While a B12 deficiency is a possible risk factor, don’t let this sway your decision not to eat vegan or vegetarian.You just need to take extra precautions to ensure you are getting an ample amount of B12. Luckily, you can easily supplement the vitamin to ensure a deficiency does not occur. Plant-based sources of B12 include nutritional yeasts and fortified breakfast cereals.


The human digestive tract is responsible for taking nutrition out of the food you consume. Still, some illnesses can reduce your body’s ability to absorb certain nutrients, including B12. 

Vitamin B12 is considered a water-soluble vitamin, which means it absorbs into water. For the most part, this makes it easily absorbed by the body as well. Still, there are certain situations where B12 may not absorb as well as it should. For example, individuals who have undergone bowel resection surgery can have a harder time absorbing B12 from their diet.

To provide more context, a bowel resection is a procedure in which a part of the bowel is removed. This procedure is usually performed in individuals with Crohn’ disease, bowel cancer, severe ulcers, or other gastrointestinal issues. When a part of the bowel is removed, it decreases the length of the digestive tract. As a result, this surgery can reduce the number of nutrients obtained through food.


An autoimmune disorder is a condition in which the body accidentally targets its own healthy cells. A few examples of common autoimmune disorders include Type 1 diabetes, rheumatoid arthritis, lupus, and psoriasis. With these disorders, the immune system destroys healthy cells, causing problems within the body. 

An important part of B12 absorption involves a protein found within the stomach. This protein is known as intrinsic factor protein (IFP). IFP works by binding to the vitamin and protecting it until it reaches the ileum in the digestive tract, where it can be absorbed. Certain autoimmune conditions can impact the cells that produce IFPs in your stomach. This can decrease the ability to absorb vitamin B12. 


Medications can come with unintended side effects, such as reducing your body’s ability to absorb B12 properly. 

One drug that could increase the chance of a B12 deficiency is metformin. Metformin is a medication that is typically prescribed to individuals with pre-diabetes or type 2 diabetes. While this drug can effectively help manage blood sugar, it can also impact your body’s ability to absorb B12 properly. It is estimated that a B12 deficiency can occur in as many as 9.5% of individuals on metformin

Metformin isn’t the only medication that can impact B12 absorption. This problem is also common in those who take certain medications for gastroesophageal reflux disease, also known as GERD. These medications work by decreasing gastric acid, which is important in absorbing B12.

How Can I Increase My B12?

Vitamins are organic compounds that the body needs in order to function. Certain essential vitamins are unable to be synthesized by the body and need to be obtained through food or dietary supplements.

Vitamin B12 falls into this category of essential vitamins. It needs to be consumed regularly, whether that be through taking supplements or choosing foods that are naturally high in B12. Below are a few of the ways you can incorporate B12 into your diet.

B12-fortified foods

The obvious answer to increasing B12 intake is to eat more of the foods that are high in this vitamin. For example, beef liver and kidneys are both naturally abundant in B12. Of course, this approach isn’t feasible for everyone, especially people who are vegetarian or vegan.

A great way to get your dose of B12 is by eating foods fortified with B12. Fortification is essentially the addition of vitamins to an existing food. Many plant-based milks, cereals, and meat alternatives are actually fortified with B12, which can help to ensure your intake is adequate.

B12 supplements

Taking vitamin B12 supplements is one of the easiest and most convenient means of increasing the amount of vitamin B12 in your body. While getting your nutrition through food is always preferred, some people need an additional boost to meet their “quota.” That’s where dietary supplements are really helpful, especially if you already have a B12 deficiency or pernicious anemia. 

How Rex MD Can Help

In summary, nutrition is undoubtedly an important part of your overall health and wellness. B12 is just one of many important vitamins your body needs to function at its very best. B12 works to combat fatigue, promote a healthy mood, and support weight loss efforts. 

The inner workings of your body are extremely complex, and keeping track of everything you need to do for your health can be challenging. Fortunately, you don’t have to do it alone. 

Rex MD's parent company LifeMD can connect you with a licensed medical professional who can offer guidance on the importance of B12 and other essential vitamins. With easy to schedule same day appointments, you don't have to worry about the hassle of visiting the doctor's office. Sign up and make an appointment to get started.

More Articles Like this

How to Prepare for Anal Sex

Anal sex can be intimidating, but these tips will help you feel prepared and secure when doing this sex position.

May 29, 2024

The Best Sex Positions for Small Penises

A big penis does not equal good sex. Discover the best positions for men who may be on the smaller side.

May 29, 2024

Priapism: Causes, Symptoms & Treatments

Discover the causes, symptoms, and treatment options to manage priapism. Learn how you can avoid long-term complications such as erectile dysfunction and penile deformity.

May 15, 2024

How to Have a Prostate Orgasm

Discover what a prostate orgasm is and effective ways to try to have one.

May 14, 2024

Why Do I Get Random Erections?

As awkward as it may be to get a random boner, it’s a sign of healthy sexual function. Find out what causes random erections and how to manage them.

May 14, 2024

Sexual Benefits of Cloves for Men

Discover the sexual benefits of cloves and why they are essential additions to men's daily diets.

April 21, 2024

Stages of an Erection

Discover the stages of a healthy erection, how long an erection should last, and how to get help if you can’t successfully get hard.

April 11, 2024

Is There a Way to Tell if a Man is Taking Viagra?

Here’s what you need to know about Viagra, including how it works, what to expect after taking it, how to tell if your partner is using it.

April 11, 2024

Does Jelqing Actually Work?

Jelqing seems to be the latest fad for penis enhancement, but how effective is it? Discover exactly what jelqing is and what health experts have to say about it.

April 10, 2024

Types of Testosterone Injections

Testosterone injections are a popular form of TRT. Here’s your guide to testosterone injections to help you determine which one may be right for you.

March 30, 2024
Back to top