The signs and symptoms of B12 deficiency parallel those of pernicious anemia, because the antibodies that lead to PA prevent the absorption of B12, and thus PA patients develop B12 deficiency. For these patients, both diseases are one and the same.
However, not every B12 deficiency is the result of pernicious anemia antibodies. The deficiency could be the result of a different medical condition, or of a low intake.
In any case, the symptoms are similar.
B12 Deficiency Symptoms: Full List
Here’s the full list of signs of low B12. Remember, many of them are also symptoms of other diseases, so don’t jump to conclusions too quickly. But as a general rule, the more symptoms you have, the more likely you are to be B12 deficient.
Neurological Symptoms of Vitamin B12 Deficiency
Neurological symptoms are dangerous, because they indicate an advanced stage of deficiency. B12 injections must be given right away, with either daily or every-other-day shots until symptoms stop improving. Neurological symptoms of B12 deficiency are:
- Numbness and tingling of the tongue, hands, thighs or feet (paresthesia).
- Difficulty walking.
- Memory loss, forgetfulness, difficulty recalling names or words.
- Disorientation, dizziness, confusion.
- Diminished perception of vibration and position.
- Cognitive decline (dementia)
- Mood swings and personality changes.
- Intellectual deterioration.
- Difficulty to concentrate.
- Abnormal reflexes (like Babinski sign), or even absence of reflexes.
- Balance, coordination and/or speech problems (ataxia).
- Unsteady walking, falling. Positive Romberg’s test.
- Tremors (rhythmical, involuntary shaking movements).
- Tinnitus, ringing or buzzing in the ears.
- Impaired pain perception.
- Nocturnal cramping.
- Changes in taste and smell.
- Sharp nerve shocks in either side of the body.
- Spinal nerve pain, often in the lower back and neck.
- Lhermitte’s sign.
- Optic atrophy, visual disturbances, blurred vision, nystagmus, blindness.
- Paralysis of any degree.
These symptoms appear because B12 deficiency strips off the myelin that covers cranial, spinal and peripheral nerves. Although progression of neurological symptoms is gradual, once they have been present for a while, they may not be reversible with treatment.
In fact, neurological signs like mood swings and personality changes may sometimes be early symptoms of what may later be manifested as full-blown psychiatric disease. Which brings us to…
Neuropsychiatric Symptoms
Surprisingly, diffuse neuropsychiatric symptoms may sometimes be the earliest signs. The psychiatric symptoms of B12 deficiency fall into several different clinical categories.
- Psychosis.
- Hallucinations.
- Schizophrenic behavior.
- Delusions.
- Sleep disturbances or insomnia.
- Depression, with or without psychotic components.
- Suicidal ideation.
- Mania.
- Anxiety.
- Personality changes.
- Paranoia.
- Irritability.
- Violent or aggressive behavior.
- Apathy.
- Inappropriate sexual behavior.
Hematological Symptoms
- Anemia.
- Macrocytosis (large red blood cells).
- Pale skin.
- Dry or cracked sores in the corners of the mouth.
- White spots, usually on the outside forearm skin.
- Hyper/hypo pigmentation of the skin.
- Hyper segmented neutrophils.
- Poor wound healing.
- Breathlessness, dyspnea on exertion, asthma, wheezing.
- Chronic fatigue, general weakness (sometimes as part of fibromyalgia).
Keep in mind, the classical symptoms of anemia are by no means obligatory, and may also be masked by excess folic acid, or concurrent iron deficiency.
Gastrointestinal Symptoms
Many disorders in the gastrointestinal tract can give rise to a deficiency of vitamin B12. Symptoms from the gastrointestinal tract, more or less pronounced, may be present:
- Loss of appetite, weight loss, malnutrition, anorexia.
- Poor digestion, bloated feeling after eating normal or even small meals.
- Irritable bowel syndrome, constipation, diarrhea.
- Gastric reflux disease.
- Giardiasis (infection of the intestine).
- Inflammation of the pancreas (pancreatitis).
- Decreased stomach acid.
- Poor mucosal function (with subsequent specific symptoms such as glossitis).
- Delayed gastric emptying (gastroparesis).
- Helicobactor pylori infection.
- Small intestinal bacterial overgrowth.
- Malabsorption syndromes like Crohn’s or celiac disease.
- Liver disease.
- Diphyllobothrium latum (fish tapeworm).
Vascular Symptoms
- Orthostatic hypotension (low blood pressure when standing up).
- Chest pain.
- Increased heart rate when changing from supine to upright position.
- Heart palpitations.
- Enlargement of the heart.
- Stroke (cerebral vascular accident).
- Mini stroke (transient ischemic attack).
- Heart attack (myocardial infarction).
- Narrowing of the arteries (occlusive arterial disease).
- Blood clotting, often in the legs (deep vein thrombosis).
- Blockage of an artery in the lungs (pulmonary embolism).
Additional Signs & Symptoms of B12 Deficiency
Vitamin B12 deficiency also affects the musculoskeletal, endocrinological, immunological, respiratory, genitourinary, and dermatological systems. Therefore, here are some other side effects of B12 deficiency that are worth mentioning:
- Increased susceptibility to infections.
- Difficulty swallowing.
- Premature greying, hair loss, dry or lifeless hair.
- Poor antibody production after vaccinations.
- Incontinence.
- Decreased libido.
- Increased urinary tract infections.
- Hypothyroidism.
- Osteoporosis.
- Fractures.
- Muscular spasms and cramps.
- Bleeding from the gums (gingival bleeding).
- Oral ulcers.
- Brittle nails.
- Decreased activity of osteoblasts (cells that build bone).
- Restless legs.
- Weakness of legs, arms, trunk.
- Glossitis, swollen/sore tongue.
- Fainting, lightheadedness.
- Enlarged spleen (splenomegaly) or liver (hepatomegaly).
Any Special Symptoms In Men or Women?
Women suffering from post-natal depression should be tested for B12 deficiency immediately. This is often due to nitrous oxide usage during labor, or as a result of a preexisting deficiency made worse by the increased B12 demands of the fetus during pregnancy. Other symptoms of B12 deficiency in women:
- Infertility.
- Recurrent miscarriage.
- Abnormal PAP smears.
- Intrauterine growth retardation.
- Post-natal depression.
As for men:
- Infertility.
- Impotence.
- Low sperm motility.
- Low sperm count.
Signs of Vitamin B12 Deficiency in Infants & Children
Children also suffer from B12 deficiency. Here are common signs:
- Developmental delay or regression.
- Decreased muscle tone (hypotonia).
- Poor weight and/or height gain, a general failure to thrive.
- An abnormally small head.
- Intellectual disabilities, lower IQ.
- Language delay or speech problems.
- Poor motor and coordination skills.
- Poor socialization.
- Difficulty in walking or writing.
- Apathy, lethargy, irritability.
- Mood disorders and psychotic behavior (here’s an example).
- Weakness, fatigue, tiredness.
- Muscle tremors, involuntary movements, tics.
- Abnormal sensations.
- Pigmented skin.
- Chronic constipation.
- Epileptic seizures (fits).
- Vision abnormalities.
- Anorexia, loss of appetite, or other eating disorders.
- Severe food allergies or sensitivities.
- Anemia.
- Stroke.
- Rooting reflex kept for more than 4-6 months of age.
- A diagnosis of celiac, thyroid disorder, or another autoimmune disease.
- A diagnosis of any neurological, psychiatric, or behavioral disorder.
That’s it.
Stay alert, as doctors and psychiatrists are often not even aware that B12 deficiency could cause such symptoms, and misdiagnosis is very common. The initial symptoms of vitamin B12 deficiency are insidious and could easily be overlooked, especially as the serum concentration of B12 can lie within the reference range.
Patients at risk for B12 deficiency should raise the index of suspicion. These include the elderly, who are especially at risk. Age-related and often asymptomatic atrophic gastritis is common, and may be enough to cause a patient to slide into a negative B12 balance with depleted cellular stores. Vegetarians and vegans as well as infants of such mothers are also in danger of developing B12 deficiency, even when mothers do not show any symptoms. This is due to the high requirement in the rapidly growing child.
Other groups at risk are patients with intestinal disease or after stomach surgery, or those with normal or autoimmune thyroid disorders (like Hashimoto’s). Also, patients on long term therapy with protein pump inhibitors and histamine receptor antagonists, or those using biguanidesfor glycemic control.
Good luck.
