Woman tired from work holding her head with both hands

Energy production and maintenance are key to everyday performance and mood. But, if you’re wondering “why do I get so tired in the afternoon?”, or experiencing low energy levels—and effects of low energy like irritability, slow response times to stimuli, or even memory loss—you may be suffering from a vitamin B12 deficiency.

Is vitamin B12 good for energy? Absolutely.

But, “energy” is much more than a qualitative measurement of mood, motivation, and physical performance—energy production is also a crucial cellular process that impacts nearly every aspect of humans’ biological functions.

In this article, we’ll explore everything you need to know about how vitamin B12 impacts energy levels and the importance of liquid energy supplements. We’ll break down B12’s roles in various energy-related physiological processes, analyze some key symptoms of vitamin B12 deficiency, and explain why B12 is crucial for optimal performance at all ages.

What is Vitamin B12?

Vitamin B12 is one of many micronutrients crucial to our physiological functions. A micronutrient is a substance that all living organisms require in small amounts in order to thrive. Vitamin B12 is a micronutrient that plays an essential role in our body’s ability to maintain healthy blood-oxygen saturation, produce DNA, and prevent megaloblastic anemia, which can cause fatigue and physical weakness.1

Vitamin B12—also called cobalamin—is one of eight key B vitamins. You’ve likely heard of other B vitamins, like:

  • Vitamin B1 (thiamine)
  • Vitamin B3 (niacin)
  • Vitamin B7 (biotin)
  • Vitamin B9 (folic acid)
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Vitamin B12 and Energy

We know that vitamin B12 supplements aid in energy production, but what about vitamin B12 for athletic performance or mental function? Let’s dive in and explore this multifaceted physiological characteristic.

Cellular Energy Production

“Energy” is more than a qualitative measure of our motivation, physical alertness, and mood—it’s also a quantifiable biological measure of cell function.

One of the most important duties of our cells is energy production. Both macronutrients—carbohydrates, fats, and proteins—and micronutrients like vitamin B12—contribute to this critical process.2 As cells convert macronutrients into ATP (cellular energy used throughout the body), micronutrients supplement the process in a variety of ways.

Vitamin B12, in particular, has two roles in energy production cycles:

  1. The water soluble vitamin B12 contributes to the oxidation of fatty acids, allowing fat to be used as an energy source.
  2. The vitamin B12 absorption catabolizes (or breaks down) amino acids, releasing ATP.

Without B12, cell energy production would quantitatively suffer.

Oxygen Transport

Our bodies require oxygen transport via blood and the circulatory system for survival. Hemoglobin, a red blood cell protein, binds to oxygen molecules, moving and depositing them throughout the body.

While you probably associate anemia with iron deficiency, a variety of B vitamin deficiencies—including B12—can also cause anemia, which reduces hemoglobin’s ability to bind to oxygen molecules, resulting in reduced endurance and efficient cellular energy use. So, healthy levels of B12 also help humans maintain optimal blood-oxygen saturation, which significantly impacts energy levels.

Impact on Mood

B12 vitally contributes to quantitative cellular energy production and efficient energy use, but it also impacts our qualitative assessment of energy level—our mood.

A 2002 study theorizes that vitamin B12 deficiency plays a role in depressive disorders. Study participants with low B12 levels were 70% more likely to experience depression symptoms than subjects with healthy quantities of B12.3

While researchers are still exploring the reasons why low B12 causes symptoms of depression, the interplay between low cellular energy production—resulting in physical fatigue—and depressed mood simply makes sense. Physical and mental health are inseparably intertwined, and when one suffers, the other is likely to follow suit.

Symptoms of Vitamin B12 Deficiency

Vitamin B12 plays a vital role in cellular energy production, blood-oxygen saturation, and qualitative mental well-being. But, what could a vitamin B12 deficiency look like in your day-to-day life?

Diminished Energy and Fatigue

All three key roles of Vitamin B12 can determine our everyday energy level and physical alertness:

  • Low cellular energy production can lead to reduced metabolism and slower cell regeneration. When the energy in our cells suffers, the effects cascade throughout the body, causing fatigue, low appetite, and dull hair, skin, and nails. The vitamin B12 benefits for skin, however, can lead to rejuvenation and renewal.

  • Reduced blood-oxygen saturation due to anemia also causes fatigue. Oxygen transport to the brain is a key function of hemoglobin, and in cases of B12-deficient anemia, low oxygen levels can reduce brain function, slowing cognition. When facing low oxygen saturation, the brain uses the limited energy available to maintain basic biological functions, reducing efforts to maintain complex cognition, speech, and critical thinking.

  • Depressive symptoms, while still under investigation by researchers, include both physical and mental fatigue. These symptoms could present as physical exhaustion, low motivation to socially engage with others, or executive dysfunction—the inability to complete basic tasks.

  • Fatigue and low energy impact people in different ways. But, when considering the possibility of a B12 deficiency, think about recent, habitual changes in your energy level, like:

    • Significantly cutting back your exercise regimen because you’re just too tired to work out
    • Opting for takeout instead of cooking because you aren’t motivated or inspired to do so
    • Reduced productivity at work, school, or home

    If any of these day-to-day impacts ring true for you, you could be experiencing B12 deficiency.

    Low Exercise Tolerance

    While we touched upon a general reduction in exercise in the previous section, low B12 can also impact the quality of your workout when you do manage to go for a run, do yoga, or lift weights.

    Low exercise tolerance is a symptom of vitamin B12 deficiency. Low tolerance and low motivation are two distinct phenomena:

    • Low motivation – If you can’t be bothered to work out, you’re too tired, or you’re trying to conserve your energy for more crucial tasks (like work or household chores), you're suffering from low motivation—a possible indication of vitamin B12 deficiency.
    • Low exercise tolerance – If you’re still motivated to work out but find that your workouts are shorter, you can’t reach your usual benchmarks, or you’re winded more easily than normal, you could be experiencing low exercise tolerance—the ability to endure prolonged periods of physical activity.

    While distinguishing between these two characteristics can help you determine how a B12 deficiency may be interfering with your everyday life, they both point to a potentially larger problem—perhaps a low B12 level. If you think it’s a different issue, learn more about the signs of a vitamin C deficiency.

    Shortness of Breath

    While you may become winded quickly as a result of low exercise tolerance, a vitamin B12 deficiency can also cause general shortness of breath.

    If you feel like you just can’t get a satisfying breath, you find yourself noticing heavy breathing outside of an exercise routine, or you have trouble completing everyday tasks—like climbing stairs, doing dishes, or carrying groceries—without pausing to catch your breath, you could be experiencing low oxygen saturation.

    While you should consult a medical professional to rule out other respiratory conditions—like an infection, asthma, or a lung injury—shortness of breath could be a potential sign that you need more B12.

    Mental and Cognitive Impairment

    Low oxygen saturation can also cause reduced mental capacity. The following are everyday examples of reduced cognitive function:

    • Speaking or responding to others slower than usual
    • Reduced short term memory (like forgetting whether or not you took your morning medication or turned off the stove before leaving the house)
    • Taking more time than usual to solve problems, think critically, or understand complex topics

    If any of the above is happening to you, don’t panic—while your symptoms could be a result of low B12, a medical professional can help you determine the cause of your reduced cognitive function and find a solution.

    How Do Healthy B12 Levels Impact Day-to-Day Functions?

    While the effects of B12 deficiency can be frightening, intimidating, or upsetting, let’s explore how healthy vitamin B12 levels can be present in your day-to-day life.

    Impacts for Infants and Children

    Healthy B12 levels as early as infancy can positively affect children’s social skills and visuospatial perception abilities, according to a 2017 study.4

    Researchers documented B12 levels in children 2-12 months old, and tested various skills five years later, discovering that children with healthy B12 levels early in life scored higher on various social and geometric puzzle tests.

    So, children performing well in school, showing age-appropriate development of social skills, and achieving cognitive benchmarks on schedule likely have adequate B12 levels.

    Adult Psychomotor Speed

    Psychomotor abilities—commonly called “reaction times”—in adults correlate to B12 levels. As we age, our psychomotor abilities typically slow down at least slightly, but a healthy B12 intake can keep us sharp.

    A variety of factors impact psychomotor speed, and B12 levels impact nearly all of them:

    • Symptoms (or lack thereof) of depression
    • General energy level
    • Cognitive function, specifically attention and complex processing
    • Oxygen availability in the brain

    If you’re satisfied with your reaction times to both physical and mental stimuli, it’s unlikely that you’re experiencing B12 deficiency.

    Lower Risk of Alzheimer's Disease in Elderly Populations

    Recent studies show that healthy B12 levels can help seniors maintain effective cognitive function and memory recollection.5

    Elderly study participants with healthy B12 levels were less likely to develop Alzheimer’s Disease and dementia than their deficient counterparts, indicating that healthy B12 levels in seniors help sustain age-appropriate cognitive abilities.

    As you can see, adequate B12 intake impacts every stage of our lives, from early childhood to old age.

    Ensure Healthy B12 Intake with Cymbiotika Synergy Vitamin B12

    Healthy B12 levels help maintain adequate cellular energy production, blood-oxygen transport, and mood, while B12 deficiencies can wreak havoc on our everyday lives. But, the positive day-to-day impacts of B12 maintenance are clear—B12 helps children thrive, keeps adults sharp, and even prevents the development of memory disorders as we age.

    But remember that plants don’t contain B12 unless they’re fortified. So, if you live a mostly-meatless lifestyle, you’ll need to supplement your B12 intake to achieve all of these positive health outcomes—and avoid the pitfalls of B12 deficiency.

    Cymbiotika’s Synergy Vitamin B12 is an organic, animal product-free blend of the two most bioavailable forms of B12—Methylcobalamin and Adenosylcobalamin—that can help you maintain adequate levels, which contributes to nerve and cell generation, energy production, and healthy skin and nails.

    Increasing your energy, vitality, and cognitive function has never been easier, or tastier—Synergy B12’s delicious berry flavor makes getting your daily B12 dose even sweeter. Try it out, and reach your maximum potential.


    1. National Institutes of Health. Vitamin B12. https://ods.od.nih.gov/factsheets/VitaminB12-Consumer/
    2. US National Library of Medicine. Vitamins and Minerals for Energy, Fatigue and Cognition: A Narrative Review of the Biochemical and Clinical Evidence. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019700/#B169-nutrients-12-00228
    3. US National Library of Medicine. Vitamin B12, folate, and homocysteine in depression: the Rotterdam Study. https://pubmed.ncbi.nlm.nih.gov/12450964/
    4. US National Library of Medicine. Vitamin B-12 status in infancy is positively associated with development and cognitive functioning 5 y later in Nepalese children. https://pubmed.ncbi.nlm.nih.gov/28330909/
    5. US National Library of Medicine. Homocysteine and holotranscobalamin and the risk of Alzheimer disease: a longitudinal study. https://pubmed.ncbi.nlm.nih.gov/20956786/

    par / 28 janv. 2022