Severe deficiency can occasionally produce significant neurological or psychological symptoms. However, memory problems have many possible causes, and B12 deficiency should not be assumed without proper evaluation.
5. Pale Skin and Heart Palpitations
B12 deficiency can cause megaloblastic anemia, a condition in which abnormal red blood cells are produced.
Possible signs include pale skin, weakness, tiredness, and heart palpitations.
Palpitations can also have many unrelated causes, so recurring or concerning episodes should be medically assessed.
6. A Sore or Red Tongue
Changes inside the mouth can occasionally provide another clue.
Vitamin B12 deficiency may cause glossitis, in which the tongue becomes sore, inflamed, or unusually red. Mouth soreness can also occur.
Because these symptoms can result from many conditions, they are most meaningful when they occur alongside other signs of deficiency.
7. Loss of Appetite or Unexplained Weight Loss
Some people with B12 deficiency experience reduced appetite and unintended weight loss.
These symptoms are nonspecific, meaning many medical conditions can cause them. Persistent unexplained weight loss should therefore be discussed with a healthcare professional rather than assumed to be a vitamin problem.
8. Mood or Psychological Changes
Vitamin B12 deficiency can affect the nervous system and, in some cases, may be accompanied by psychological symptoms.
These may include:
Low mood
Anxiety
Irritability
Confusion
More severe deficiency can sometimes be associated with significant cognitive or psychological changes.
Mental-health symptoms should never be assumed to result solely from a vitamin deficiency.
9. Vision Problems
Vitamin B12 deficiency can occasionally affect neurological pathways related to vision.
Vision changes are less common than fatigue or tingling, but the NHS lists visual problems among possible complications of B12 deficiency.
Sudden or significant changes in vision require prompt medical evaluation.
Who Is More Likely to Develop Vitamin B12 Deficiency?
Several factors can increase the likelihood of deficiency.
People following vegan or highly restrictive diets
Because naturally occurring B12 is found primarily in animal-derived foods, people who avoid these foods generally need reliable fortified foods or supplementation.
People who cannot absorb B12 properly
A person may consume adequate B12 and still become deficien
Conditions affecting absorption can include autoimmune gastritis or pernicious anemia, gastrointestinal disorders, and certain types of stomach or intestinal surgery.
Older adults
