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Tired at the gym? Vitamin B12 deficiency might be the culprit

Written by: Anu Munkhtur



Time to read 6 min


Are you aware of the silent epidemic that could be sabotaging your fitness goals?

Vitamin B12 deficiency, a condition that is alarmingly prevalent worldwide, can significantly impact your health, sleep and gym performance.

We'll explore the tell-tale symptoms, debunk common misconceptions, and discuss the broader implications of this deficiency.

Vitamin B12 deficiency, tiredness/fatigue, gym performance, symptoms, sleep

1. Unravelling the Symptoms of B12 Deficiency

Vitamin B12 deficiency, a condition that affects a significant portion of the global population, manifests in a variety of symptoms.

These symptoms range from physical signs such as rapid breathing, headaches, indigestion, loss of appetite, palpitations, vision problems, weakness, tiredness, diarrhoea, and a sore or red tongue, to cognitive changes like memory issues, understanding difficulties, and judgment problems.

Additionally, neurological symptoms such as numbness, muscle weakness, psychological problems, balance and coordination issues, pins and needles sensation, and even incontinence can occur.

While these symptoms serve as crucial indicators for early detection and prevention of severe conditions, their broad spectrum and commonality with other ailments can lead to misdiagnosis or delayed treatment.

These symptoms can occur even in individuals who have not developed anaemia due to B12 or folate deficiency. 

Vitamin B12 deficiency, tiredness/fatigue, gym performance, symptoms, sleep

1.2. Debunking Misconceptions About B12 Deficiency

The common misconceptions about B12 deficiency often oversimplify the complex nature of this health issue.

Many people believe that a simple blood test can accurately diagnose a deficiency, but this is not always the case.

B12 deficiency can be masked by  high folate levels , and some people may have normal B12 levels but still exhibit deficiency symptoms due to functional B12 deficiency.

The assumption that everyone requires the same amount of B12 fails to account for individual dietary needs and preferences.

For instance,  vegans and vegetarians may require higher B12 supplementation due to the lack of B12 in plant-based diets.

The prevalence of B12 deficiency may inadvertently reflect socio-economic and demographic factors.

For example, older adults, people with certain medical conditions, and those with limited access to nutritious food are more prone to B12 deficiency.

This raises questions about the fairness and inclusiveness of the diagnosis. 

"We are what we repeatedly eat. Healthy eating is not an act, but a habit."

Felicity Luckey

1.3. The Causes of Vitamin B12 Deficiency

According to a study in the National Library of Medicine, vitamin B12 deficiency can arise from three main sources:

1. Autoimmune Issue (Pernicious Anaemia):

  • Your body mistakenly attacks healthy cells in your stomach that normally help absorb B12.

  • This prevents your body from using B12 properly, leading to a deficiency.

2. Absorption Problems:

  • Certain situations can make it harder for your body to absorb B12:

    • Gastric bypass surgery: This reroutes the digestive system, bypassing the area where B12 is typically absorbed.

    • Small intestine damage: Diseases like Crohn's disease or infections can harm the part of the small intestine responsible for B12 absorption.

  • Even with normal B12 production, these situations can lead to a deficiency.

3. Dietary Insufficiency (Vegans):

  • While rare, strict vegans who don't consume animal products for extended periods (around 3 years) can develop a B12 deficiency.

  • This is because B12 is naturally found mainly in animal products.

If your doctor suspects you might have a B12 deficiency, they will likely order some initial tests:

  • Complete blood count (CBC) with a peripheral smear: This checks for changes in your red blood cells, which can be affected by B12 deficiency.

  • Serum B12 and folate levels: These tests directly measure the levels of B12 and folate in your blood, which can help confirm or rule out a deficiency.

If these initial tests aren't conclusive, your doctor may order additional tests:

  • Methylmalonic acid (MMA) and homocysteine levels: These tests can also be helpful in diagnosing B12 deficiency, especially if the initial tests are unclear.

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1.4. The Broader Impacts of B12 Deficiency

This condition not only affects individual health but also has broader societal impacts.

For instance, the B12 deficiency is more common in people whose families come from northern Europe, indicating a potential genetic predisposition.

Moreover, certain risk factors such as autoimmune diseases, strict vegetarian diets , and being an older adult, point to the fact that certain demographic groups are more susceptible.

Severe B12 deficiency can lead to serious complications such as an abnormally fast heartbeat and heart failure

Vitamin B12 deficiency, tiredness/fatigue, gym performance, symptoms, sleep

2. The Role of Vitamin B12 during Training

Vitamin B12 plays a crucial role in training and athletic performance.

It aids in the production of red blood cells, which are responsible for delivering oxygen to the brain and muscles, which is especially impactful during exercise.

This function is particularly beneficial for endurance athletes, as increased oxygen delivery can enhance performance.

According to a National Library of Medicine study, athletes, deficient in B12 who supplement with it, especially in conjunction with other B-vitamins, often experience improved exercise performance.

However, it's important to note that vitamin B12 did not have an increased performance effect on athletes who weren’t deficient in it.

As you train, remember that maintaining optimal levels of vitamin B12 not only boosts your performance but also contributes to your overall health. 

2.1. The Impact of Vitamin B12 on Sleep and Rest

Research has shown that Vitamin B12 can significantly influence our sleep patterns and overall rest.

A study published in the National Library of Medicine found that the administration of Vitamin B12 led to a significant decrease in daytime melatonin levels, which in turn increased daytime alertness and concentration.

On the other hand, it also led to an increase in nocturnal melatonin levels, promoting better sleep at night.

Another study found that Vitamin B12 increased the amount of time participants spent in deep sleep.

Some studies have found that low levels of Vitamin B12 are associated with insomnia, while others have found that high levels in young adults can lead to better sleep quality.

Therefore, maintaining optimal levels of Vitamin B12 is crucial for achieving a balanced sleep-wake cycle. 

Vitamin B12 deficiency, tiredness/fatigue, gym performance, symptoms, sleep

2.2. Maintaining Optimal Vitamin B12 Levels for Better Sleep

The key to maintaining optimal levels of Vitamin B12 lies in a balanced diet rich in animal-based products like red meat, poultry, fish, eggs, and milk.

These foods are naturally high in Vitamin B12 and can help you meet your daily requirement of 2.4 micrograms.

For vegetarians and vegans, fortified foods like cereals, soy milks, and meat-replacement products can provide a dietary source of B12.

However, it's recommended to take a B12 supplement to ensure adequate levels.

Over-the-counter multivitamins usually contain sufficient B12 to cover your daily requirement.

Regular blood tests can also be beneficial in monitoring your B12 levels and adjusting your diet or supplement intake accordingly.

Remember, while Vitamin B12 plays a significant role in sleep regulation, it's not the only factor. A holistic approach that includes a balanced diet, regular exercise, and good sleep hygiene is essential for optimal sleep health. 

3. The Importance of Balanced Nutrition for Sleep and Rest

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