Adequate amounts of B-12 are required for blood cell formation and proper nerve function. It is found in foods, such as fish, meat, poultry, eggs, milk and dairy, and many products ate fortified with it. According to the Office of Dietary Supplements, when the level in the blood drops to 170 to 250 picograms per mililiter deficiency symptoms can occur. Deficiencies can occur with no known reason or be due to a disease that restricts the body's ability to absorb vitamin B-12. A lack of B-12 can cause various neurological symptoms, which require medical attention.
A lack of vitamin B-12 can lead to nerve damage which can cause sensations of numbness and tingling, warns the National Institutes of Health. This can occur anywhere in the body but is most common in the hands and feet. Grasping objects, walking and maintaining balance may become challenging due to a loss of sensation. Depending on the severity of the deficiency, adding foods high in B-12 into the diet may be enough, while more severe cases require vitamin B-12 shots.
If B-12 levels become too low, patients can become shaky, weak and it may be challenging to coordinate movement. In severe cases, paralysis can occur.
Vitamin B-12 deficiency is most common among strict vegans and the elderly. With age, diseases that interfere with digestion are more common and there are many medications that can hinder the body from using B-12 properly.
For most consuming one chicken breast, one hard-boiled egg and 1 cup plain low-fat yogurt daily will meet the requirement. A cup of raisin bran with 1 cup of milk also contains the daily amount needed.
Other warning signs of a B-12 deficiency include confusion, dementia, hallucinations, psychosis, paranoia, depression, violent behavior and personality changes claims the Centers for Disease Control and Prevention. The good news is that in most cases these symptoms can be resolved by bringing B-12 levels back to normal. If even mild changes in cognitive ability are noticed, it is important to seek medical attention and have the level of vitamin B-12 tested.
While rare, a vitamin B-12 deficiency can cause damage to the nerves and muscles that control vision. This can lead to changes in vision such as blurriness or sight loss. The difficulty in detecting a deficiency, is that it tends to occur slowly and symptoms may be so subtle that they are not recognized or attended to. Symptoms may progress so slowly that a patient may adapt to them without realizing something is wrong. However, it can be caught during a routine blood test, so regular testing is essential especially in those at a higher risk.
- National Institutes of Health: B12 Deficiencies
- Centers for Disease Control: CME Tutorial on Detection of B-12 Deficiency: Why Vitamin B 12 Deficiency Should Be on Your Radar Screen: A Continuing Education Update
- Centers for Disease Control and Prevention: Manifestations of Low Vitamin B12 Levels
- Merck: Vitamin B12