Vitamin B12 Deficiency Signs and Symptoms You Shouldn’t Ignore

If you lack vitamin B12, it may take six to 12 months to fully recover. Vitamin B12 deficiency is common, especially among vegetarians and older adults. Vitamin B12, also known as cobalamin, is a water-soluble vitamin present in meat, fish, and dairy.

This vitamin is crucial for brain and nerve function, and its deficiency can lead to headaches, fatigue, muscle weakness, and depression. The shortage may result from insufficient B12 in your diet or the body’s inability to absorb it due to another medical condition. Diagnosing B12 deficiency can be challenging as its symptoms mimic those of other health issues.

Now, let’s talk about the importance of Vitamin D:

  • It enhances mood.
  • It improves lung function.
  • It reduces the risk of multiple sclerosis, cancer (especially prostate, breast, and colon cancers), and diabetes.
  • It protects against heart diseases, including high blood pressure and heart failure.
  • It prevents bone fractures, falls in older people, and osteoporosis.

Concerning B12 needs, they vary throughout life. Daily recommendations (in micrograms) are as follows:

  • Birth to 6 months: 0.4 mcg
  • 7-12 months: 0.5 mcg
  • 1-3 years: 0.9 mcg
  • 4-8 years: 1.2 mcg
  • 9-13 years: 1.8 mcg
  • 14-18 years: 2.4 mcg
  • 19 years or older: 2.4 mcg

Keep in mind that these are minimums to avoid deficiency, not necessarily optimal levels. For instance, research suggests higher daily intakes for healthy blood levels.

During pregnancy and breastfeeding, B12 requirements increase to support fetal growth and development: 2.6 mcg per day during pregnancy and 2.8 mcg while breastfeeding. Some experts recommend higher intakes for breastfeeding individuals to maintain optimal blood levels.

Various factors can cause B12 deficiency, such as autoimmune issues (like pernicious anemia), malabsorption (intestinal damage or surgery), and low dietary intake (common in long-term vegans or strict vegetarians). Certain medications, like metformin and proton pump inhibitors, can also lead to B12 deficiency by interfering with absorption.

What Leads to a Lack of Vitamin B12?

There are various factors that can contribute to a deficiency in vitamin B12, and some of them are beyond an individual’s control. The three primary causes of B12 deficiency include:

  1. Autoimmune Issues: Pernicious anemia, an autoimmune condition, hinders the absorption of B12 in the small intestine, resulting in low B12 levels.
  2. Malabsorption: Certain individuals may struggle to absorb B12 effectively due to intestinal damage or surgery. For instance, those who have undergone gastric bypass surgery or had part of their bowel removed may be more prone to developing a B12 deficiency.
  3. Low Dietary Intake: Vitamin B12 is naturally present in animal-based foods like fish, meat, poultry, eggs, and dairy. If your diet lacks sufficient B12-rich foods, you may become deficient in B12. This deficiency is more common in individuals who have followed vegan or strict vegetarian diets for an extended period.

Additionally, the prolonged use of specific medications has been associated with B12 deficiency. Medications such as metformin, which lowers blood sugar, and proton pump inhibitors used for acid reflux can interfere with B12 absorption, potentially causing a deficiency over time.

Signs of Low Vitamin B12 Levels


If you experience a sensation of “pins and needles” in your hands, feet, or legs, it could be a sign of low B12 levels. B12 deficiency may damage the protective sheath around nerves. Diseases such as celiac, Crohn’s, or other gut issues, as well as certain heartburn medications, can hinder the absorption of this vitamin.

Feeling Colder Than Usual

Insufficient B12 can result in a shortage of healthy red blood cells, leading to anemia. This may cause you to feel excessively cold, particularly in your hands and feet.

Brain Fog

A lack of B12 is associated with various cognitive issues, including depression, confusion, memory problems, and even dementia. It can also impact your balance. Daily B12 supplements at a recommended dose of 2.4 micrograms for adults are generally considered safe. Excess B12 is excreted through urine, but high doses may lead to side effects such as dizziness, headache, anxiety, nausea, and vomiting.


If your muscles feel weak, and you experience fatigue or lightheadedness, it could indicate a lack of B12. While your doctor can assess your B12 levels, not all of it may be usable by your body. It’s crucial to be attentive to symptoms, whether they develop gradually or appear suddenly, and to inform your doctor.

Smooth Tongue (Atrophic Glossitis

If your tongue becomes smooth and glossy, a condition known as atrophic glossitis, it may signal B12 deficiency. This occurs as tiny bumps called papillae on the tongue waste away. Infections, medications, and other factors can contribute, but insufficient B12 or other nutrients can also make your tongue sore.

Herbivores Beware

B12 deficiency is uncommon because the body can store a multi-year supply of it. However, since plants don’t contain B12, vegans and vegetarians who avoid animal products should incorporate fortified grains like breads, crackers, and cereals into their diet.

Heart Palpitations

Sudden racing or irregular heartbeats, felt in the throat or neck, may be a sign of B12 deficiency. While chicken, eggs, and fish are good sources of B12, beef liver is exceptionally rich in this vitamin and can be beneficial for addressing such symptoms.

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