The Most Common Cause of B12 Deficiencies

author avatar Dr. Eric Berg 02/28/2024

Vitamin B12 Deficiency Symptoms: Causes and Solutions

Recognizing the early warning signs of vitamin B12 deficiency is essential for preserving good health. Learn about the signs and symptoms of inadequate B12 levels and their potential consequences on your overall well-being.

In addition, explore gastric acid's role in absorbing B12 and why low stomach acid can be the leading cause of B12 deficiency.  Lastly, discover natural remedies for improving stomach acid and vitamin B12 absorption rates while emphasizing the importance of identifying and addressing the root cause behind a persistent vitamin B12 deficiency. 

Vitamin B12 Deficiency Symptoms

A deficiency in vitamin B12 can lead to various symptoms, including fatigue, pale skin, memory problems, anemia, and neurological issues like peripheral neuropathy and memory problems.

These symptoms may indicate an issue with the absorption of this essential nutrient rather than its presence in the diet.

Fatigue and Weakness

One of the most common signs of vitamin B12 deficiency is feeling tired or weak throughout the day.

This occurs because your body relies on healthy red blood cells for tissue oxygenation and energy production; however, low vitamin B12 levels can impair red blood cell production, increasing the risk of anemia characterized by fatigue and weakness.

Pale Complexion

When developing a B12 deficiency, you might notice that your skin appears paler than usual.

This is due to a lack of healthy red blood cells circulating through your body responsible for giving the skin its natural color.

Memory Problems and Dementia Risk

Vitamin B12 is vital in maintaining brain health by helping produce neurotransmitters necessary for cognitive function.

A severe deficiency could result in memory problems or even increase one's risk for dementia later in life. It's crucial to maintain adequate levels of this nutrient as part of a nutritious diet or via supplementation if necessary.

Neurological Issues Linked to Vitamin B12 Deficiency: 

  • Numbness: Vitamin B12 helps maintain nerve cell health; therefore, low, inadequate levels may cause numbness or tingling sensations in hands and feet - also known as peripheral neuropathy.

  • Muscle Weakness: B12 deficiency can lead to muscle weakness, making it difficult for individuals to perform daily tasks or engage in physical activities.


Pernicious anemia, a type of megaloblastic anemia, is caused by impaired B12 absorption and results in immature red blood cells being circulated, which can cause fatigue, shortness of breath, and dizziness. 

Other causes of megaloblastic anemia include folate deficiency or certain medical conditions like celiac disease.

If necessary, it's essential to address any underlying issues causing impaired blood cell production through dietary changes or supplementation.

The Role of Stomach Acid in B12 Absorption

B12 deficiency is usually not caused by insufficient dietary intake but by inadequate absorption due to low stomach acid levels. The stomach's pH changes as we age, making absorbing sufficient amounts of vitamin B12 harder.

Importance of Stomach Acidity for Nutrient Absorption

Stomach acid plays a crucial role in breaking down proteins and releasing essential nutrients such as vitamin B12 from food sources.

The acidic environment also helps activate intrinsic factors, a protein produced by the stomach lining necessary to absorb vitamin B12 properly. When there is insufficient stomach acid, vitamin B12 absorption is impaired, which can lead to deficiencies over time.

Common Causes Leading to Low Stomach Acid Levels

  • Aging: Our body's ability to produce sufficient hydrochloric acid decreases naturally as we age. This decline can contribute significantly to developing vitamin B12 deficiencies later in life.

  • Gastritis: Inflammation or irritation within the gastric mucosa can lead to reduced production and secretion of gastric acids required for optimal digestion and absorption processes.

  • Medication: Certain medications like proton pump inhibitors (PPIs) or antacids may lower your overall gut acidity level, impairing digestive function and reducing vitamin B12 uptake. 

  • Hypothyroidism: An underactive thyroid gland has been linked with decreased production of stomach acid, which may contribute to poor absorption of vitamin B12.

All of these factors can lead to low stomach acid levels, which are detrimental for overall health and well-being.

Age-Related Decline in Stomach Acid Production

Aging is a natural process that often results in reduced stomach acid levels.

According to research, approximately 30% of adults over 50 have atrophic gastritis, a condition characterized by diminished secretion of hydrochloric acid within the stomach lining.

This decline can lead to impaired absorption and utilization of essential nutrients like vitamin B12, contributing significantly towards deficiency symptoms such as fatigue or anemia among older individuals. 

Signs You May Have Low Stomach Acid Levels

Recognizing signs of low stomach acid is crucial for addressing deficiencies related to poor absorption. Some common indicators include acid reflux, GERD (gastroesophageal reflux disease), gas, bloating, or other digestive discomforts after meals. 

Acid Reflux and GERD Symptoms

Gastroesophageal reflux disease (GERD), a more severe form of acid reflux, occurs when the lower esophageal sphincter does not close properly, allowing stomach contents to flow back into the esophagus.

This can cause heartburn, chest pain, difficulty swallowing, and regurgitation of food or sour liquid.

Contrary to popular belief, these symptoms may indicate low stomach acid rather than excessive amounts as it hinders proper digestion, leading to undigested food particles irritating the gastrointestinal tract.

Gas and Bloating After Eating

If you frequently experience gas and bloating after consuming rich meals could signal an issue with inadequate gastric acidity.

Low stomach acid impairs the breakdown of proteins, resulting in their fermentation by gut bacteria, which produces excess gas, leading to uncomfortable bloating sensations post-meals.

Digestive Discomforts Indicating Possible Imbalance

  • Indigestion: Persistent indigestion, or dyspepsia, can indicate low stomach acid. This may manifest as fullness or discomfort in the upper abdomen during or after meals.

  • Nausea and vomiting: In some cases, inadequate gastric acidity can cause nausea and vomiting due to the inability to digest food particles properly.

  • Constipation or diarrhea: Low stomach acid levels can disrupt the balance of gut bacteria, leading to irregular bowel movements such as constipation or diarrhea.

To manage these symptoms and improve the body's ability to absorb essential nutrients, like vitamin B12, one must focus on increasing stomach acidity levels with natural remedies or dietary modifications. 

Natural Remedies for Improving Stomach Acidity & Absorption Rates

You can take several steps to improve your body's ability to absorb vitamin B12 effectively from food sources or supplements.

Apple cider vinegar and ox bile supplementation are beneficial, as well as increasing mineral intake through sea salt consumption or potassium-rich foods, which aid digestion overall.

The Role Of Ox Bile In Absorbing Vitamin B12 And Other Nutrients

Bile is a substance secreted by the liver that emulsifies fats and facilitates their absorption through the intestinal wall. This process is also crucial for the uptake of the fat-soluble vitamins A, D, E, and K, as well as minerals such as calcium, magnesium, zinc, etc.

Additionally, the numerous digestive benefits of ox bile help stimulate the production of bicarbonate secretion from the gallbladder, helping neutralize stomach acid and further enhancing digestion.

Nutritional Yeast As A Source Of Vitamin B12

Nutritional yeast is a deactivated yeast with a cheesy flavor, making it popular among vegans and vegetarians as a cheese substitute. Nutritional yeast is also an excellent source of B vitamins, including vitamin B12.

It is an ideal supplement for those who do not consume animal products or have difficulty absorbing nutrients from their diet due to medical conditions like celiac disease or Crohn's disease.

If you suspect deficient B12 levels, consult your healthcare provider about testing options to evaluate your vitamin B12 status and formulate an appropriate dietary strategy or supplementation protocol.

apple cider vinegar

Apple Cider Vinegar for Low Stomach Acid 

One popular natural remedy for improving stomach acid levels is apple cider vinegar (ACV).

ACV contains acetic acid, which can help boost the amount of hydrochloric acid produced in the stomach for better nutrient absorption. Add one tablespoon to a glass of water to incorporate ACV into your diet, and drink it before meals.

Sea Salt, Potassium, and Iodine as Essential Minerals

Incorporating essential minerals like sea salt, potassium, and iodine into your diet can also support healthy stomach acidity levels.

Sea salt provides trace minerals necessary for proper digestive function, while potassium helps regulate fluid balance within cells, aiding digestion.

Additionally, iodine is essential to thyroid health, directly impacting metabolism and nutrient absorption rates.

Consider using high-quality sea salt instead of table salt when cooking or seasoning dishes; consuming potassium-rich foods such as avocados, bananas, or spinach; and ensuring adequate iodine intake by eating seaweed products like nori sheets.

Dietary Changes to Promote Better Nutrient Absorption

  • Consume fermented foods: Foods like sauerkraut, kimchi, kefir, or yogurt contain beneficial probiotics that support a healthy gut microbiome and may improve digestion overall.

  • Avoid antacids and acid-blocking medications: These drugs can further decrease stomach acid levels, making it even harder for your body to absorb vitamin B12. Discuss your concerns with a healthcare provider to identify alternative solutions for taking antacids or acid-blocking drugs. 

Implementing these natural remedies and dietary changes into your daily routine can improve stomach acidity levels and enhance your body's ability to absorb essential nutrients such as vitamin B12 effectively.

Addressing the Root Cause of B12 Deficiency

By improving stomach acid levels through natural remedies or dietary adjustments, you can enhance your body's ability to absorb vitamin B12 and reverse potential symptoms of vitamin B12 deficiency.

In many cases, vitamin B12 deficiencies are not caused by inadequate intake but rather by poor absorption due to low stomach acid levels. It's essential to determine whether you have low stomach acid.

Monitoring Progress After Implementing Changes

  • Dietary modifications: Incorporate foods rich in vitamin B12, such as meat, fish, and poultry 

  • Natural Remedies: Utilize apple cider vinegar before meals and add sea salt containing iodine for better mineral balance, which aids digestion and nutrient absorption. 

  • Lifestyle adjustments: Manage stress levels and maintain regular exercise routines, promoting healthy digestion.


Vitamin B12 deficiency symptoms can range from fatigue and weakness to neurological issues like peripheral neuropathy. Addressing the root cause of poor vitamin B12 absorption is essential to promote healthy levels. 

Severe deficiency can lead to megaloblastic anemia, characterized by immature red blood cells, and can have side effects like fatigue and weakness.

Improving stomach acidity through natural remedies like apple cider vinegar and oxbile supplementation and consuming plenty of vitamin B12-rich foods promotes normal vitamin b12 status. 

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