Vitamin B12 Deficiency Symptoms

By Temma Ehrenfeld @temmaehrenfeld
September 27, 2023
Vitamin B12 Deficiency Symptoms

Have your blood tested and take a supplement for vitamin b12 deficiency symptoms if necessary. As we age, it gets harder to absorb this vitamin from food.

It’s easy to mistake the symptoms of vitamin B12 deficiency for a sign of other illness. Especially in older adults, many of the symptoms of aging may be due in part to a deficiency in vitamin B12, which helps make DNA and nerve and blood cells. It’s also crucial for a healthy brain and immune system.

As you age, it’s harder for your body to absorb this vitamin from food.

Doctors don’t routinely check your B12 blood levels. The normal blood level of vitamin B12 ranges between 200 and 600 picogram/milliliter. If you have vitamin B12 deficiency symptoms, your doctor may decide to give you a supplement even if you are in the low-normal range of up to about 300 picogram/milliliter.


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Vitamin B12 deficiency signs and symptoms

The classic vitamin B12 deficiency disease is pernicious anemia, when your red blood cells stay large and immature. But long before you have anemia, vitamin B12 deficiency symptoms appear as the condition builds up.

  • Are you always tired in the afternoon despite a good night’s sleep?
  • Is it hard to carry home a bag of groceries?
  • You may have odd sensations like “pins and needles” from nerve damage, a symptom of B12 deficiency.
  • You may have pale skin.
  • Your tongue may be smooth — lacking some of the little tastebud bumps — and you may find that your taste is diminished.
  • You might be moody.

Doctors are most likely to suspect B12 deficiency if you complain of fatigue plus another symptom, or you are in one of the groups at risk.   

Vitamin B12 foods

Meat is the main source of B12, so vegetarians are at risk of a deficiency. If you are taking the diabetes drug Metformin, ask for a test. Up to 30 percent of people taking Metformin are short on B12, and the problem is more likely if you also take drugs to reduce stomach acid.

The groups most vulnerable to B12 deficiency are:

Vegetarians and vegans often think they’re getting B12 from plant sources — seaweed, fermented soy, spirulina, and brewer’s yeast — but it’s not clear how much B12 those sources provide. Children, elderly people, and pregnant women who are also vegetarian are likely to have a B12 deficiency.

What is the treatment for B12 deficiency?

It depends on why you have the problem. You can eat meat and have a B12 deficiency if you have trouble absorbing the vitamin. People with inflammatory gut disorders like Crohn’s disease may not absorb the vitamin properly. If absorption is the problem, you may require injections. High dose oral or nasal administration may be an alternative.

But many people can treat B12 deficiency successfully with a supplement.


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September 27, 2023

Reviewed By:  

Janet O’Dell, RN