Signs of Vitamin B12 Deficiency

Vitamin B12 is a crucial nutrient that the human body requires for various processes, such as the synthesis of DNA, energy production, and the normal functioning of the nervous system.

Although this Vitamin is easily found in various animal-based food items, deficiency of Vitamin B12 is quite common due to lack of dietary intake, malabsorption, and certain medical conditions.Deficiency often occurs in people of older ages.

Normal B12 Levels

A level above 300 pg/mL is considered normal, while a level of vitamin B12 dosage between 200 and 300 pg/mL is considered borderline, and levels below 200 pg/mL are considered a deficiency.

The ability of the human body to absorb B12 from food declines with age; hence deficiency is common in older people. Still, that doesn’t mean children and younger people can’t develop B12 deficiency. Most of the time, lack of B12 is misdiagnosed due to insufficient lab testing or may be due to the symptoms observed are not specific to Vitamin B12 deficiency alone.

What to do if you suspect Vitamin B12 deficiency?

If you feel that you might have a B12 deficiency, you need to visit a health care professional at the earliest to discuss your symptoms and have the diagnostic tests done by them.

Signs and Symptoms of Vitamin B12 Deficiency

Let’s cover the nine most often seen symptoms related to the deficiency of Vitamin B12 and how this is diagnosed and treated.

Fatigue and tiredness

Your body needs Vitamin B12 to function actively; having low levels of B12 will ultimately result in decreased production of Red blood cells, which can disturb oxygen delivery through the body resulting in tiredness.

Moreover, deficiency in B12 can also cause megaloblastic Anemia; this condition regards the formation of large-sized immature and abnormal Red blood cells and impaired synthesis of DNA. When your body lacks healthy Red blood cells to carry oxygen to tissues, you probably will feel weak and tired.

Dull skin

Pale or yellow skin is yet another sign that indicates B12 deficiency. Anemia related to B12 deficiency causes this paleness to your skin. Its deficiency may also cause a condition known as jaundice which changes the color of your eyes to yellow, and your skin also turns yellowish. This coloration is due to high bilirubin levels; a waste product formed when Red blood cells gradually break down.


Deficiency of B12 levels can also lead to side effects related to neurology, including severe irregular headaches. Headache is the most common symptom related to Vitamin B12 deficiency in both kids and adults.


Vitamin B12 is necessary for the functioning of your central nervous system, and a lack of this Vitamin can surely disturb your mental health; its deficiency increases the risk of developing depression.

Its deficiency can increase the level of homocysteine, a sulfur-containing amino acid, which may contribute to depression by gradually elevating oxidative stress, damaging DNA, and causing cell death in the body.

GIT Issues

Diarrhea, Constipation, nausea, vomiting, and bloating gas can be due to a lack of B12 levels in the body. Both adults and children may get affected by these issues.

Mental Impairment

Due to the deficiency of Vitamin B12, one might feel difficulty concentrating on different things. Its dearth negatively affects the central nervous system; people with this problem find it difficult to solve and complete the tasks assigned.

Older age people are highly at risk for these side effects as the risk of B12 deficiency increases with age.


Inflammation and pain of the tongue and mouth are considered glossitis which can be caused by B12 deficiency; glossitis can appear alongside with stomatitis and are pretty common in people with B12 deficiency-related Anemia, yet can also occur without anemia and can be an early sign of B12 deficiency.


It is a medical condition that refers to a burning or pin and needles sensation in some parts of the body, like in hands and feet.

Other signs and symptoms of Vitamin B12 deficiency

Including these above-mentioned symptoms, there are numerous other signs that you might observe when lacking Vitamin B12; some of them are:

  • Muscle cramp
  • Muscle weakness
  • Impaired coordination
  • Erectile dysfunction
  • Vision disturbances


Vitamin B12 is essential, and its deficiency can lead to many severe problems; you may observe some early and late signs and symptoms if your body lacks this specific Vitamin.

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