FAQ: Do Normal (Healthy) People Get Sick from Low Vitamin B12?

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Thousands of people in the US suffer from vitamin B12 deficiency; some questions people often have are, “How did my B12 levels get so low? I eat healthy and I don’t have any chronic illnesses, so how did I become anemic?” That’s a complex question to answer, because there are many ways that people become gradually deficient in this crucial B vitamin.

FAQ: Do Normal (Healthy) People Get Sick from Low Vitamin B12?

First, why is vitamin B12 important?

Vitamin B12 (cobalamin) is a water-soluble B vitamin that is essential for basic survival.

  • Vitamin B12 helps to keep your nervous system functioning normally, as it sustains myelin, a fatty coating that protects your nerve cells and enhances intercellular communication.
  • Vitamin B12 also supports a healthy metabolism in converting fuels into much-needed energy and synthesizing DNA.
  • Vitamin B12 is required for proper red blood cell formation, as it helps to maintain a healthy level of normal-sized functioning red blood cells for oxygen transportation to your brain, organs, and cell tissues throughout your body.
  • Vitamin B12 helps to control levels of homocysteine, a hormone that has been linked with increased risk for heart attack, stroke, and Alzheimer’s disease.

How do you get vitamin B12?

So we know that vitamin B12 is important; now the question is, “What foods are high in vitamin B12?”

  • The richest sources of vitamin B12 are animal-based foods such as meat, poultry, seafood, milk, and eggs.
  • Still, if you have vitamin B12 malabsorption, a common risk factor for vitamin B12 deficiency, then you must take supplemental forms of vitamin B12 in order to prevent pernicious anemia. (More on vitamin B12 malabsorption later.)

These Foods are Highest in Vitamin B12

Symptoms that mean you need more B12

It’s always good to test for low vitamin B12, but the best way to know if you’re getting enough is by paying close attention to telltale symptoms of severe vitamin B12 deficiency.

Since vitamin B12 depletion happens slowly, you may not realize you’re experiencing a deficiency until you start to notice yourself always feeling tired, depressed, or just generally slower than usual.

Here are some of the most common symptoms of low vitamin B12:

  • Constant overbearing fatigue
  • Long-lasting depression
  • Brain fog
  • You’re talking slower than normal
  • Memory loss
  • Anxiety
  • Agitation
  • Painful numbness and tingling in the hands and feet
  • Burning, sore red tongue
  • Muscle spasms
  • Difficulty walking in a straight line
  • Constantly dropping things

Risk factors

If you keep a vegan diet, or refrain from eating many animal-based foods, then you are a risk factor for vitamin B12 deficiency, simply because there are no vegetable-based foods that supply sufficient amounts of vitamin B12 to prevent anemia.


If you’re not a vegan, and you have no chronic illnesses, then you may still be at risk, as there are a number of medications that interfere with your ability to digest vitamin B12 naturally from foods, resulting in vitamin B12 malabsorption- a major cause of vitamin B12 depletion that often slips off the radar.

Some medications that lead to vitamin B12 malabsorption include:

  • Metformin (for diabetes)
  • Protein pump inhibitors (for acid reflux, heartburn)
  • NSAID’s (ibuprofen, etc.)
  • Certain antibiotics

Here is a longer list of medications that cause vitamin B12 deficiency


If you have had a gastric bypass for weight loss, then you may be at risk for vitamin B12 deficiency. Also, gastrointestinal surgeries recommended for treating Crohn’s disease, such as removal of the ileum, necessitate frequent vitamin B12 supplementation in order to prevent pernicious anemia.


Peripheral neuropathy (nerve damage) from vitamin B12 deficiency is one of many ailments that occur with long-term alcohol abuse.

Autoimmune disorders

An underlying autoimmune disorder can also be the basis of low vitamin B12. Autoimmune intrinsic factor dysfunction causes your body to attack intrinsic factor, a digestive enzyme that bonds to vitamin B12 and helps to distribute it into your blood supply. People with autoimmune pernicious anemia cannot get vitamin B12 from foods, regardless of diet, and must use supplemental forms of vitamin B12 for survival.

If you have any other autoimmune disorder, such as celiac disease, fibromyalgia, or lupus, then your risk for autoimmune vitamin B12 deficiency is higher than normal.

GI damage

Finally, any kind of damage to your stomach, intestines, or esophagus can interfere with your ability to absorb vitamin B12, increasing your chance for pernicious anemia. If you suffer from chronic heartburn, gas, and bloating, then that may be an important clue in determining why you often feel tired, anxious, or agitated.

Illnesses that cause frequent vomiting, such as migraines, fibromyalgia, and Crohn’s, are linked with comorbid vitamin B12 deficiency.

Old age

As we age, our bodies tend to slow down; that includes a reduction in the amount of digestive enzymes we produce- proteins needed to absorb vitamin B12. For many healthy individuals over 60, signs of depression and forgetfulness are often discounted as the first symptoms of senility, without even checking vitamin B12 levels.

For that reason, health experts recommend strict vitamin B12 supplementation for all senior citizens, even if they don’t think they need it, as the symptom don’t manifest themselves until vitamin B12 levels reach a dangerous low.


Don’t ignore symptoms of vitamin B12 deficiency, even if you are “healthy” and “normal.” Plenty of people have vitamin B12 deficiency, and don’t even know it- not until they start experiencing severe ailments.

Get a blood test, take your vitamin B12, and keep track of your mood and energy levels each day; this will be your best Richter scale for determining how much vitamin B12 you need in order to prevent anemia and maintain good health.

Also read:

Vitamin B12 Deficiency- Can it be Genetic?

Vitamin B12 Deficiency Caused by H. Pylori Infection

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