Can You Take Too Much B12?

Can You Take Too Much B12?

We've all had those days — waking up feeling lethargic with our thoughts clouded and every task seeming like a mountain to climb. 

Maybe you've blamed it on a poor night's sleep or an overloaded schedule. While those can be contributing factors, our bodies often communicate with us through feelings. This brings us to our diet, an important yet often overlooked component of our well-being. 

While big names like vitamin C typically take the limelight, especially during flu season, vitamin B12 is its less-talked-about counterpart. This water-soluble vitamin, though lesser known, plays a key role in our overall health. 

In this guide, we aim to shine some more light on this essential nutrient, help you identify if you’re experiencing a deficiency, and offer a few ways that you can get more of it each day.

What Is Vitamin B12 and Why Do We Need It?

The scientific name for vitamin B12 is cobalamin, although it can sometimes be known as cyanocobalamin or methylcobalamin, depending on its form. Regardless of its name, vitamin B12 is one of the most essential water-soluble vitamins, as it’s important for optimal health. Its many functions are intrinsic to our body's operations. 

Let's dive a little deeper into the variety of ways that B12 supports our health.

Neurological Function

Vitamin B12 plays an essential role in protecting our nervous system. It's responsible for producing myelin, which is a protective covering that helps limit nerve damage. 

By doing so, it ensures efficient communication between the brain and different parts of the body. Not only that, but B12 also aids in the creation of neurotransmitters, the body's chemical messengers that play a crucial role in mood, energy, and cognition. 

Red Blood Cell Formation

Red blood cells are our body's delivery agents, supplying oxygen from the lungs to various tissues. Vitamin B12 is fundamental in the production of these cells. A shortage could lead to pernicious anemia, manifesting as fatigue, weakness, and pallor.

Protein Metabolism

Just as a car requires fuel to run, our bodies require food to produce energy. Vitamin B12 facilitates the metabolism of proteins, breaking them down into amino acids. These amino acids are then utilized to repair tissues, produce energy, or form new proteins.

DNA Synthesis

At the heart of our very being is DNA. Vitamin B12 assists in the replication and regulation of DNA, ensuring cells divide and reproduce correctly. This function is important for maintaining skin health, healing wounds, and overall growth.

Energy Production

Ever wonder what gives you the zest to tackle your day? B12 (along with the other B-complex vitamins, including niacin and riboflavin) plays a significant role in converting the food you consume into glucose. This glucose is then burned to produce energy, propelling you through your daily activities.

Mental Health

While physical health is tangible and often easy to gauge, mental health is more subtle yet equally significant. As B12 is directly involved with neurotransmitter synthesis, it has a direct link with our emotional and cognitive well-being. 

Can You Take Too Much Vitamin B12?

You may be thinking that if B12 is so beneficial, then why not take a few megadoses and make sure you’re covered? Well, the reason that won’t work is because B12 is a water-soluble vitamin. Our bodies have a fairly nifty system in place for vitamins like these: You take what you need and excrete any excessive amounts through urine. 

That means that even incredibly high doses of vitamin B12 won’t result in toxicity. The tolerable upper intake level for B12 is virtually unreachable, even if you’re consuming large doses of vitamin supplements. In other words, it’s almost impossible to experience a vitamin B12 overdose. 

Of course, taking large amounts of vitamins can still result in a few undesirable side effects, including headaches, nausea, vomiting, and diarrhea. So, it’s best to consult with a healthcare provider and follow their expert medical advice instead of taking matters into your own hands. 

What Are Symptoms of a Vitamin B12 Deficiency?

In today’s fast-paced world, it's easy to overlook the signals our bodies send us. Yet, these signs often serve as a barometer, indicating an internal imbalance. With vitamin B12 being so important, having low levels can cause a wide range of symptoms.

Common symptoms of B12 deficiency include:

  • Fatigue
  • Pale skin
  • Disrupted vision
  • Mood changes
  • Mouth ulcers
  • Dizziness
  • Breathlessness
  • Altered tastes
  • Poor coordination

Who Is at Risk for a Vitamin B12 Deficiency?

B12 deficiencies don't discriminate and can affect anyone. However, certain groups are more susceptible due to specific reasons.

These include:

  • Older adults: As we gracefully age, our stomach produces less acid, which is key for B12 absorption. 

  • Vegetarians and those who eat vegan diets: Vitamin B12 is predominantly found in animal products, which means vegetarians and vegans may need to supplement.

  • Some medications: People who take metformin to manage diabetes can struggle to maintain a sufficient supply, as the drug is known to reduce B12 levels in patients. 

  • Gastric bypass surgery: This surgery, designed for weight loss, can reduce the amount of B12 the body can absorb from food.

  • Excessive alcohol drinkers: Alcohol affects kidney function as well as the liver, which is crucial for storing vitamin B12. 

How Much B12 Do You Need Each Day?

The importance of balancing our nutrient intake cannot be understated. While we often focus on macronutrients like proteins, fats, and carbohydrates, micronutrients, such as vitamin B12, are equally vital for our well-being. But how much of this essential nutrient do we really need daily?

The RDA (recommended dietary allowance) for vitamin B12 is meticulously curated by nutrition experts, taking into account various factors to determine the right quantity. For most adults, the golden number hovers around 2.4 mcg (micrograms) daily. But just like any nutritional recommendation, this isn't a one-size-fits-all scenario. 

For example, pregnant women might require a tad more, nudging towards 2.6 mcg. On the other hand, breastfeeding mothers, providing for their little ones, may need up to 2.8 mcg. It's crucial to cater to these evolving needs to ensure both mother and child remain in good health.

How Can You Determine Your Vitamin B12 Levels?

Knowing is half the battle. If you've ever experienced symptoms that hint towards a vitamin B12 deficiency or if you belong to a group that's naturally at risk, it's wise to get clarity. Enter the world of medical diagnostics. 

With just a simple blood test, your healthcare provider can paint a clear picture of your B12 status. It not only gauges the current levels but also helps strategize potential dietary changes or supplements if needed.

How Can You Get More Vitamin B12?

There’s no denying that vitamin B12 is essential for your health. Fortunately, there are several ways to ensure that you’re getting enough of it on a daily basis.

Food Sources

In the vast culinary world, there's no shortage of sources to get your vitamin B12 fix. 

Foods rich in vitamin B12 include:

  • Lean meats
  • Seafood
  • Eggs and dairy products
  • Fortified foods like breakfast cereals


In an ideal world, our daily meals would provide us with all the nutrients we need. However, in reality, factors like dietary restrictions, lifestyle, or food availability can lead to gaps in our nutrient intake. 

For vitamin B12, if you find your diet isn't meeting the mark, over-the-counter vitamin B12 supplements can be the answer. Whether you choose a dedicated B12 pill or a multivitamin that contains a spectrum of essential vitamins and minerals, these supplements ensure that you meet your daily dose. 

Additionally, for those who love a sprinkle of flavor, nutritional yeast, often fortified with B12, can be a delicious additive to meals, offering both taste and nutrition.

B12 Injections

For some people, merely swallowing a pill doesn't address the core of their B12 deficiency. This can be due to severe deficiencies or issues with nutrient absorption in the digestive tract. In such scenarios, vitamin B12 injections can be a game-changer. 

Unlike oral supplements, these injections introduce the vitamin directly into the bloodstream, bypassing any potential digestive hurdles. Administered under strict medical supervision, B12 shots are an efficient way to quickly elevate and stabilize B12 levels, ensuring optimal health and well-being.

The Bottom Line

Vitamin B12 is an essential nutrient that you need to take every day. If you find yourself at an increased risk of a deficiency, then it’s important to review your diet or consider the use of supplements. Before making any major changes, it’s best to consult with your doctor first. 

Remember, while our focus today was B12, our overall health is a mosaic of different elements. So, for more advice and insights into achieving optimal health and wellness, consider following Dr. Kellyann on social media and visiting our blog. You'll find a treasure trove of information awaiting you!


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