Vitamin B12: Everything you need to know


Vitamin B12 is one of eight B vitamins. The human body needs vitamin B12 in order to maintain neurological function and a healthy nervous system. Vitamin B12 is responsible for the production of DNA and the generation of red blood cells. It’s also an essential nutrient in pregnancy.

Vitamin B12 Deficiency Risk Factors

If you’re a vegan or vegetarian, you could be at risk for vitamin B12 deficiency as B12 is naturally found in animal products. Other risk factors include following a having immune system disorders or conditions that affect the small intestine. Frequent heavy drinking and use of acid-reducing medications may also cause vitamin B12 deficiency. It can also be more difficult to absorb vitamin B12 with age.

Foods High in Vitamin B12

Vitamin B12 can be found in a variety of foods including:

  • dairy products
  • eggs
  • fish
  • meat
  • poultry


Vitamin B12 is found in animal-based products or in the form of supplements. Vitamin B12 fortified foods include grains for vegans and vegetarians as Vitamin B12 is generally not present in plant foods.


During pregnancy, vitamin B12 crosses the placenta and is present in breast milk. A woman experiencing vitamin B12 deficiency during pregnancy may be at risk for giving birth to children with developmental delays and growth defects. Pregnant woman, vegans, and vegetarians should talk to their doctor about how to get enough vitamin B12.

Recommended Daily Intake

Vitamin B12 is water-soluble{crosslink} meaning it won’t be stored in the body for long so it’s important to take the recommended daily amount regularly. The recommended dietary allowance varies and is dependent on your age, gender, diet, and medical condition. The general RDA is 2.4 micrograms for adults. Vitamin B12 supplements are recommended for pregnant women, breast-feeding woman, vegans, and vegetarians.

Signs and Symptoms of Deficiency

Early detection of vitamin B12 deficiency is important. Quick treatment is important to prevent severe neurologic problems and blood disease. Although some symptoms are slow to surface, some symptoms can hit right away.

Symptoms include:

  • numbness or tingling in the hands, legs or feet
  • anemia
  • swollen and inflamed tongue
  • cognitive difficulty or memory loss
  • weakness, fatigue, or lightheadedness
  • shortness of breath and heart palpitations
  • Constipation, diarrhea, loss of appetite, or gas


If left untreated in the long run, vitamin B12 can have serious repercussions on the body such as vision or memory loss, anemia, depression, and behavioral changes. Long term damage can lead to irreversible nerve damage.

Vitamin B12 Deficiency Treatments

Vitamin B12 injections and nasal spray can be prescribed to treat Vitamin B12 deficiency. High-dose oral vitamin B12, daily B12 supplement, or a multivitamin that contains B12 are all common solutions.

Vitamin D Overdose

High doses of vitamin B12 may cause dizziness, headache, anxiety, nausea, and vomiting.

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by Insider Envy Staff

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