Got a question? Call us on 01253 928393
30 day money-back guarantee
Added to your bag

What are the symptoms of B12 deficiency?

Vitamin B12, a vital nutrient required for optimal bodily function, plays an essential role in maintaining the nervous system, brain function, and red blood cell production. A deficiency in this essential vitamin can result in a myriad of symptoms that may initially appear subtle, but may potentially escalate to severe health issues if left unchecked.

Fatigue and Weakness: A Classic Early Indicator

A common symptom that surfaces in the initial stages of Vitamin B12 deficiency is persistent fatigue and weakness. As Vitamin B12 is essential for energy production and red blood cell formation, a deficiency can lead to a diminished oxygen supply to cells and tissues, resulting in an overwhelming sense of exhaustion.

Neurological Symptoms: When the Nervous System Suffers

A deficiency in Vitamin B12 can adversely affect the nervous system, leading to a range of neurological symptoms. These may include:

  • Numbness and tingling: A sensation of "pins and needles" in the extremities, such as hands and feet, often indicates nerve damage caused by the deficiency.
  • Difficulty with balance and coordination: Impaired nerve function may manifest in difficulties with balance and coordination, increasing the risk of falls and accidents.
  • Memory loss and cognitive decline: A deficiency in Vitamin B12 may result in a decline in cognitive function, leading to memory loss, difficulty concentrating, and even dementia in severe cases.

Gastrointestinal Disturbances: The Hidden Effects

Vitamin B12 deficiency can also lead to various gastrointestinal disturbances, often overlooked as indicators of a deficiency. These may include:

  • Loss of appetite: A decreased desire to eat or unexplained weight loss may be due to insufficient Vitamin B12 levels.
  • Constipation or diarrhea: A disruption in the balance of gut bacteria, a result of B12 deficiency, can cause constipation or diarrhea.
  • Sore, red, or swollen tongue: Known as glossitis, this condition can be attributed to a lack of Vitamin B12 and can cause discomfort or difficulty swallowing.

Anaemia and Associated Symptoms: When Red Blood Cells Falter

A primary consequence of Vitamin B12 deficiency is megaloblastic anaemia, a condition characterised by abnormally large and immature red blood cells. This can lead to the following symptoms:

  • Pallor: Pale skin and the inside of the lower eyelids may indicate a reduced number of red blood cells.
  • Rapid heartbeat or shortness of breath: In an attempt to compensate for the reduced oxygen-carrying capacity of the blood, the heart may beat faster, and you may experience shortness of breath.

Mood Disturbances: The Psychological Impact

Vitamin B12 is crucial for synthesising various neurotransmitters that regulate mood, such as serotonin and dopamine. Consequently, a deficiency can result in mood disturbances, including:

  • Depression and anxiety: A lack of Vitamin B12 can contribute to the development of mood disorders such as depression and anxiety.
  • Irritability and mood swings: Fluctuations in mood or increased irritability may also indicate a deficiency in Vitamin B12.


The symptoms of Vitamin B12 deficiency can vary from mild to severe, and can potentially be debilitating if left untreated. If you suspect a deficiency, consult a healthcare professional who can provide guidance on appropriate diagnostic testing and treatment options. Early intervention is crucial to mitigate potential complications and ensure optimal health and well-being.




    Guides & articles