Vitamin B12 Deficiency: Are You At Risk? (8 min.)

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Vitamin B12 is one of many nutrients in the family of B vitamins.  These B vitamins work together to help the body convert food into the fuel needed for daily use†, so it is important not to have a B12 deficiency.  Vitamin B12 individually is crucial for its role in DNA synthesis†, normal brain function†, and red blood cell production†. The misconception of energy production stems from its role in supporting the metabolism of every cell in the body. And while a deficiency of B12 can lead to tiredness or weakness, returning to healthy levels of B12 restores normal energy levels†, but there is no evidence it will go further.

Unfortunately, the body cannot produce vitamin B12, and it must be obtained through diet or supplementation†. It is naturally found in animal products such as fish, poultry, meat, eggs and dairy. Commercial breakfast cereals are often fortified with Vitamin B12 (in the manufactured cyanocobalamin form), but the levels are typically quite low, well under 30 micrograms (mcg) per serving.

Yet despite these food sources, the NIH suggests that deficiency affects around 3 percent of younger adults, but rates increase significantly with age and in those with risk factors†.

Who’s at Risk of Vitamin B12 Deficiency?

While most of us consume enough B12 in our diet, deficiencies do occur.  As most adults age, stomach acid levels decrease, reducing the number of nutrients absorbed. B12 is one of these nutrients, but typically, eating fortified foods or taking a B12 supplement can negate this absorption loss†. Many groups are at risk for deficiency because their conditions lower the body’s ability to absorb the nutrient when it is consumed. Digestive diseases also limit the amount of B12 the stomach can absorb. Individuals with Crohn’s and celiac disease often require additional B12 through food or supplements to maintain healthy levels†. Additionally, individuals who have undergone weight loss surgery or other gastrointestinal procedures may experience difficulties absorbing sufficient B12 from a standard diet†. If you feel you might fall into one of these categories, it is important to consult with your physician to have your B12 levels checked.

Lastly, vegetarians and vegans have a higher risk of deficiency as B12 food sources are only from animals†. This finding was also reinforced by a study done comparing diabetic vegetarians and omnivores. Higher levels of inflammation were correlated with reduced levels of B12 in vegetarians†. For anyone considering a plant-based diet, it is highly recommended to consult with your physician about maintaining adequate nutrient levels to support a healthy lifestyle.

A strict vegan or vegetarian diet can be a risk factor for vitamin B12 deficiency, as it involves consuming fewer or no animal products. As vegans don’t consume any food from animals, fortified foods and supplements are the only sources of vitamin B12 for vegans†. A vitamin B12 supplement is a good option to ensure adequate intake and levels are maintained†.

In contrast, for some people, consuming enough B12 is not an issue.  Instead, a reduction in stomach acid greatly impairs the body’s attempt to extract this nutrient from food. There are many reasons a person might be experiencing a reduction in stomach acid levels.

Here is a list of common reasons for low stomach acid:

• Older Adults with decreased stomach acids†
• Regular use of proton pump inhibitors Prevacid® (lansoprazole), Prilosec® (omeprazole), and Nexium® (esomeprazole)
• Frequent antacid use
• Heavy drinking
• Gastrointestinal surgery, including weight loss surgery†
• Pernicious anemia (an autoimmune disease)
• Gastrointestinal conditions such as Crohn’s or celiac disease†
• Pernicious anemia

A person who falls into the above categories should consult their physician about their B12 levels in the blood.

Why Folic Acid Can Mask B12 Deficiency

Folic acid and B12 both support red blood cell production and DNA health†. But only B12 supports brain function†. If folic acid levels are high, they can normalize blood markers — even when B12 levels are critically low — delaying the diagnosis of neurological symptoms.

Signs and Symptoms of Vitamin B12 Deficiency

Because symptoms develop gradually, a vitamin B12 deficiency is often mistaken by loved ones for signs of aging. Symptoms of a B12 deficiency include:

• Memory problems
• Mood changes or depression
• Muscle weakness
• Extreme fatigue
• Low blood pressure
• Numbness or tingling in hands and feet
• Shakiness
• Unsteady gait
• Incontinence

The only way to confirm a B12 deficiency is through a blood test. If the blood test confirms a deficiency, your physician or health care provider will determine what is needed to raise your blood levels. This often involves a combination of solutions, including dietary changes, lifestyle modifications, and supplements.

Contrary to popular opinion, increasing B12 intake past normal amounts does not increase energy levels†. The NIH states specifically that “except in people with a vitamin B12 deficiency, no evidence shows that vitamin B12 supplements increase energy or improve athletic performance†.”

Best Food Sources of Vitamin B12

Improving B12 vitamin levels can be accomplished with a variety of foods, including these B12-rich options:

• Fish and seafood
• Beef (especially liver)
• Poultry
• Nutritional yeast
• Eggs
• Milk, yogurt and cheese
• Fortified breakfast cereals
• Nutritional yeast

Note: It’s important to check the nutrition facts of breakfast cereal to determine the amount of B12 each serving has.

Vitamin B12 Supplementation

All B vitamins are water-soluble. Excess B12 (and the other water-soluble vitamins) are flushed out in urine. So mega-dosing with B-complexes, energy drinks, and other products is ineffective unless you are actually deficient†.

Many over-the-counter supplements use the cyanocobalamin form of B12, which the body must convert. All Cooper Complete multivitamins and B complex contain the active form of vitamin B12, methylcobalamin†. For those who need additional supplementation, we offer a physician-formulated Vitamin B12 methylcobalamin supplement that supplies 1000 micrograms (mcg) of Vitamin B12 in each serving.

B12 Key Takeaways

• B12 is critical for DNA, red blood cells, and brain function†
• Deficiency is common, especially in older adults, vegetarians and vegans, and those with GI issues†
• A blood test is the only way to know if you’re deficient
• Supplements are effective and safe, especially when using the active form†

Before starting any supplement, it’s important to talk with your physician or health care provider, especially if you suspect a B12 deficiency. A simple blood test can determine your levels and help guide the right treatment plan, whether through diet, lifestyle changes, or supplementation. Everyone’s needs are different, and your provider can help ensure you’re supporting your health safely and effectively.
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Cooper Complete June 18, 2025