Vitamin B12 is an essential nutrient that contributes to many vital bodily functions. It plays a crucial role in the formation of red blood cells and the formation of DNA (the genetic material in all cells of the body), energy production, and central nervous system function. (1)(2)

Even though the vitamin is found in many foods, deficiency in vitamin B12 is a common problem. And this article covers Vitamin b12 deficiency complications.

Vitamin b12 deficiency complications

If left untreated, vitamin B12 deficiency causes many physical, neurological, and psychological problems.

• Depressive symptoms 

Unfortunately, vitamin B12 deficiency is associated with an increased risk of depression due to its crucial role in the functioning of the central nervous system.

Additionally, vitamin B12 deficiency can lead to elevated levels of the amino acid homocysteine, which contributes to increased oxidative stress, DNA damage, and cell death in the body.(2)

Furthermore, vitamin B12 deficiency generally affects mental health, increasing the risk of psychosis and other mood disorders.

• Cognitive Impairment and Difficulty Concentrating

Vitamin B12 plays a role in forming red blood cells, which are responsible for delivering oxygen to various cells in the body. Therefore, a deficiency in this vitamin can decrease the amount of oxygen reaching the brain.

This explains why individuals with a deficiency in vitamin B12 may experience cognitive impairment, difficulties in logical thinking, memory loss, difficulties in concentration, and task completion.(2)(4)

Several studies have linked vitamin B12 deficiency to an increased risk of Alzheimer’s disease, Parkinson’s disease, and vascular dementia.

• Tingling hands and Feet

One of the complications of vitamin B12 deficiency is experiencing paresthesia (a medical term referring to a burning or pins-and-needles sensation) in various body parts, such as the hands and feet. Several studies have evidenced this.

This is due to the role of vitamin B12 in the functioning of the nervous system. It contributes to the production of myelin, the protective coating shielding the nerves. A deficiency in vitamin B12 leads to insufficient myelin production, causing nerve damage and problems with nerve conduction. (2)(4)

• Trouble Walking

Peripheral neuropathy is a problem that can result from vitamin B12 deficiency, contributing to balance and coordination disturbances, movement problems, and difficulty walking.(4)

• Pale Skin

Vitamin B12 deficiency can cause yellowing and paleness of the skin due to the body’s inability to produce an adequate amount of fully-matured, healthy red blood cells, which circulate beneath the skin and give it its natural color.(4)

• Persistent Fatigue

Vitamin B12 deficiency can lead to megaloblastic anemia, where red blood cells become large, abnormal, and immature. They become weak, break down quickly, and cannot carry and transport oxygen. This causes a persistent feeling of fatigue. (4)

• Other Side Effects

Other complications of vitamin B12 deficiency include the following:(2)(4)

1. Muscle cramps and muscle weakness as it negatively impacts the function of motor and sensory nerves.
2. Erectile dysfunction in men due to elevated levels of homocysteine.
3. Vision disturbances resulting from optic nerve damage.
4. Frequent headaches.
5. Loss of appetite and weight loss.
6. Constant feelings of nausea, vomiting, and diarrhea.
7. Shortness of breath.
8. Mouth and tongue inflammation.
9. Persistent rapid heartbeat.

The normal level of vitamin B12 in the body

Dear reader, it is important to note that the normal ranges may vary slightly between different laboratories using different measurements. However, the normal values for vitamin B12 levels in the body generally range from 160 – 950 picograms per milliliter.

Values below 160 picograms per milliliter indicate a deficiency in vitamin B12, which, if left untreated, can cause the previously mentioned problems.(3)