Vitamin B12 deficiency is more common than many people realize and it can cause a wide range of symptoms, from fatigue to nerve problems.
Because symptoms can be subtle or mistaken for other conditions, it often goes undiagnosed. Knowing what to look for can help you get the care you need.
We spoke with Tiffone Powers-Parker, a registered dietitian and nutritionist with Banner Health, about the signs, causes and treatment options.
What is vitamin B12 deficiency?
Vitamin B12 (cobalamin) is an essential nutrient that supports your nervous system, red blood cell production and overall health.
Your body cannot produce B12 on its own, so you must get it from food or supplements.
“Vitamin B12 is a water-soluble vitamin that plays a key role in brain and nerve function and helps your body make red blood cells,” Powers-Parker said.
What are the symptoms of B12 deficiency?
Symptoms can develop slowly and may worsen over time.
Common symptoms include:
Fatigue or weakness
Tingling or “pins and needles” in hands or feet
Difficulty walking or balance problems
Pale or yellow skin
Mouth sores
Memory problems or confusion
Depression
“Symptoms may include fatigue, tingling in the extremities, weakness, memory changes and mood shifts,” Powers-Parker said. “If left untreated, deficiency can lead to serious complications.”
If left untreated, B12 deficiency can lead to permanent nerve damage.
What causes vitamin B12 deficiency?
There are two main causes:
Poor absorption
Your body may not properly absorb B12 due to:
Low stomach acid (common with aging)
Pernicious anemia
Gastrointestinal conditions like Crohn’s disease or celiac disease
Weight loss surgery
Certain medications
“For B12 to be absorbed in the body, it must first be digested in the stomach and combined with a protein called intrinsic factor,” Powers-Parker said. “When this process doesn’t work properly, it can lead to deficiency.”
Not getting enough B12
You may not get enough B12 if you:
Follow a vegetarian or vegan diet without supplementation
Have limited intake of animal-based foods
Who is at risk for B12 deficiency?
You may be at higher risk if you:
Are older
Have digestive disorders
Have had stomach or intestinal surgery
Take certain medications
Follow a restrictive diet
How is B12 deficiency diagnosed?
Your health care provider may order blood tests to check your B12 levels.
In some cases, additional tests such as methylmalonic acid or homocysteine levels, may be needed for a more accurate diagnosis.
“Standard blood tests don’t always catch every case,” Powers-Parker said. “More sensitive markers like methylmalonic acid or homocysteine levels may be needed to confirm a deficiency.”
How is B12 deficiency treated?
Treatment depends on the cause and may include:
Dietary changes
Oral B12 supplements
B12 injections
Treating underlying conditions
“B12 can be taken in several forms, including oral supplements, injections and multivitamins,” Powers-Parker said. “Your provider can help determine which option is best for you.”
With proper treatment, most people improve quickly.
Can you prevent B12 deficiency?
You may be able to reduce your risk by:
Eating foods rich in B12 (meat, fish, dairy and fortified foods)
Limiting alcohol intake
Taking supplements if recommended
Frequently asked questions about B12 deficiency
What are the first signs of B12 deficiency?
Fatigue, tingling in the hands or feet and memory issues are common early signs.
Can B12 deficiency be serious?
Yes, untreated deficiency can lead to nerve damage and other complications.
How long does it take to recover?
Many people feel better within weeks of starting treatment.
Do I need a B12 supplement?
It depends on your diet and risk factors. Your provider can help you decide.
The bottom line
Vitamin B12 deficiency is common but often overlooked. Recognizing the symptoms early and getting proper treatment can help prevent serious complications.
If you’re experiencing symptoms or are at risk, talk to a Banner Health provider about testing and treatment.
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