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Vitamin B12 Deficiency Symptoms

Vitamin B12 is the most extensive and structurally complicated vitamin and can be produced industrially only through bacterial synthesis.

  • Cobalamin has a close relationship with folate, as both depend on the other to work correctly.

It plays a vital role in memory, heart health, bone health, the nervous system, blood formation, proper sleeping patterns, healthy eyes, the aging process, disposition, and more. “Cobalamin” derives its name from the fact it contains a molecule of Cobalt.

Having a diet rich in cobalamin or taking a daily supplement can help increase energy levels, improve memory function and enhance our moods. In addition, it assists in preventing heart attacks, strokes, and several other serious health problems. It also helps prevent megaloblastic anemia that makes a person tired and weak.

Cobalamin can treat:

  • memory loss
  • Alzheimer’s disease
  • boost mood
  • energy
  • concentration
  • the immune system
  • slow the aging process
  • heart disease
  • lowering high homocysteine levels
  • male infertility
  • diabetes
  • sleep disorders
  • depression
  • mental disorders
  • weak bones (osteoporosis)
  • swollen tendons
  • AIDS
  • inflammatory bowel disease
  • asthma
  • allergies
  • vitiligo
  • preventing cervical and other cancers
  • skin infections

Cobalamin comes in several forms, including;

  • Methylcobalamin
  • Cyanocobalamin
  • Hydroxocobalamin

Daily Dose

According to the Food and Drug Administration (FDA), the amount of cobalamin a person needs each day depends on age. According to the FDA, the recommended adult daily intake is 2.4 micrograms (mcg).

It is a water-soluble nutrient that the human body needs but doesn’t naturally produce. It is one of the eight elements in the Vitamin B Complex. Having a diet rich in B12, or taking a daily supplement, can help increase energy levels, improve memory function and elevate our moods. It also assists in staving off heart attacks, strokes, and several other diseases. Conversely, a deficiency in vitamin B12 can cause serious health risks. It is a co-enzyme for many different nutrients and plays a vital role in DNA.


Symptoms can include slow thinking, memory impairment, attention deficits, and dementia. In addition, there is a direct and indirect correlation between low Cobalamin levels and cognitive function, both in healthy older adults and patients with Alzheimer’s disease.

  • “A common trait in heart disease, Alzheimer’s, depression, and osteoporosis patients is B12 deficiency….”

Cobalamin deficiency symptoms are often similar to other conditions. So, the best way to determine whether someone has a vitamin B12 deficiency is by having a test done by their primary care physician. A blood test can accomplish it.

Here are some of the possible symptoms of having a deficiency of B12:

  • Fatigue
  • Depression
  • Imbalance, Tipsy
  • Tingling in the Hands or Feet
  • Muscle Stiffness & Weakness
  • Reduced Cognitive Capabilities
  • Diminishing Memory
  • Low Blood Pressure
  • Sleep Disorders

Best Sources

Here is a list of some of the best natural food sources of vitamin B12

-beef is an excellent source

– fortified breakfast cereals

– cooked liver is the #1 source

– salmon, rainbow trout, and tuna

– cooked clams are a great source

– milk, cheese & eggs

Sources of Cobalamin are primarily in liver, fish, beef, cheese, chicken, eggs, milk, and clams. It is within the digestive tract of animals making animal protein products the best sources of it. Animals integrate B12 into their tissues via bacterial symbiosis, so animal foods are naturally the wealthiest source of cobalamin. It does not occur in fruits, vegetables, or grains. Plants can’t manufacture it.

Animal Protein

Beef liver and clams contain the highest amount of B12. Fortified breakfast cereal is also a good source. Here is a chart showing the significant foods with vitamin B12 and cobalamin per serving in micrograms.

   Natural Food Sources

3 oz servings

(unless otherwise noted)   mcg’s per serving  

  Cooked Clams 84  

  Beef Liver 71  

  Sardines 7.5  

  Fortified Breakfast Cereal (bowl) 6  

  Wild Rainbow Trout 5.4  

  Cooked Sockeye Salmon 4.8  

  Farmed Rainbow Trout 3.5  

  Swiss Cheese 2.7  

  Tuna Fish 2.5  

  Lamb 2.2  

  Double Cheeseburger 2.1  

  Haddock 1.8  

  Beef, Top-Sirloin, broiled 1.4  

  Milk (1cup) 1.2  

  Yogurt (1cup) 1.1  

  Beef Taco 0.9  

  Ham, cured roasted 0.6  

  1 Egg, large, hard-boiled 0.6  

  Chicken Breast 0.3  

  SOURCE: National Institute of Health min. daily requirement 2.4 mcg’s  


If you ever wondered what vitamin B12 is good for, there are many benefits to getting enough cobalamin. Adequate intake of vitamin B12 is essential for normal blood and neurological function. Vitamin B12 deficiency can produce blood, nerve, and psychological symptoms. It is also necessary for maintaining lots of energy.

  • Key Role in Memory Function

According to the National Institute of Health (NIH), poor memory is possible even at levels only slightly lower than usual. In addition, according to the FDA, “Deficiencies of vitamins B1 and B12 can affect the memory”.

  • Helps Maintain Healthy Nervous System

It is mandatory for neurological function. B12 plays a vital role in maintaining the sheath covering and protecting the nerves’ central and peripheral nervous systems. Cobalamin deficiency can cause neurological changes, such as numbness and tingling in the hands and feet.

  • Component of Mental Health

Cobalamin levels are directly associated with cognitive function. According to the NIH, deficiency in vitamin B12 can result in overall mental decline. Cobalamin deficiency can cause attention deficits, acute mental status, and acute cognitive changes. In addition, low Cobalamin levels can disrupt the electrical activity of the brain.

  • Vital to Red Blood Cell Production

Anemia is a condition in which the body does not have enough healthy red blood cells. As a result, the body needs cobalamin to make red blood cells. Red blood cells provide oxygen to body tissues.

  • Cofactor with Other Nutrients

According to the NIH, Vitamin B12 acts as a cofactor in a variety of vital bodily functions. Being a cofactor means B12 works together with other nutrients enabling them to perform their roles properly.

  • Supports Cardiovascular Health

According to the NIH, B12, folate, and vitamin B6 are all involved in homocysteine metabolism. Therefore, if it is deficient, homocysteine levels can rise due to the impaired function of methionine synthase. This condition can cause heart disease.

  • Helps Maintain Healthy Bones

Bone marrow requires a constant supply of cobalamin. Cobalamin can treat osteoporosis. A new study links deficiency with low bone mineral density in men and confirms similar, previously reported findings in women.

  • Protects Cell DNA

Sustaining DNA integrity is dependent on both folate and vitamin B12. Vitamin B12 synthesizes fatty acids in myelin and in conjunction with folate for DNA synthesis. Therefore, Cobalamin deficiency may increase the risk of breast cancer.

  • There is no evidence of any known clinical benefits when persons who are not deficient take it.


Low cobalamin can cause damage to the brain and nervous system. At levels only slightly lower than average, a range of symptoms such as fatigue, depression, and poor memory. For a person lacking enough cobalamin, cognitive changes may very well occur. These may include loss of concentration, memory loss, disorientation, dementia, and mood changes. Insomnia, impotence, and impaired bowel and bladder control can also develop.

A cobalamin deficiency can cause serious health risks. Unfortunately, it’s often underdiagnosed because physicians do not routinely test for it, and, as some experts suggest, many people with so-called “normal” levels of B12 do have a deficiency. Additionally, some of the physical manifestations of a lack can mimic other diseases, in essence distracting healthcare professionals from testing for lack of the nutrient in an individual.

Case reports describe the association of Cobalamin deficiency with delirium and dementia. In addition, low Cobalamin levels have been correlated negatively with cognitive functioning in otherwise healthy elderly adults.

Vitamin B12 deficiency can potentially cause severe and irreversible damage, especially to the brain and nervous system.

According to the latest research, “mild Vitamin B12 deficiency is associated with accelerated cognitive decline.” Severe Cobalamin deficiency can lead to depression, paranoia, delusions, memory loss, incontinence, loss of taste and smell.

The problem isn’t just getting enough of it. The problem can be getting it into the bloodstream, where it can be effective. Processing B12 requires a phenomenon known as the “Intrinsic Factor,” which protects the cobalamin from stomach acids on its journey through the stomach. Unfortunately, as a person gets older, their intrinsic factor often loses its capabilities, and therefore ingested Vitamin B12 does not get adequately absorbed.

97 Million U.S. Adults May Be Deficient

According to a government study, nearly 40% of all Americans may have a B12 deficiency. However, in 2000, a government study indicated Cobalamin deficiency is far more widespread than formerly believed. This study concluded a whopping 39 percent of the studied group of 3,000 had low Cobalamin levels. Most surprising to the researchers was that low B12 levels were typical in younger people and the elderly. The study covered people from 26 to 83 years old.

Not Just Older Adults

Evidence from the Framingham Offspring Study suggests the prevalence of Cobalamin deficiency in young adults might be more significant than previously assumed. The study found the percentage of participants in three age groups (26-49 years, 50-64 years, and 65 years and older) with deficient blood levels of vitamin B12 was similar. The study also found that individuals who took a supplement containing vitamin B12 or consumed fortified cereal more than four times per week were much less likely to have a Cobalamin deficiency.


Liquid Drops

Liquid cobalamin can be obtained by prescription or over-the-counter. It is taken orally, usually once per day. Always follow the directions carefully.


Cobalamin comes in tablet form for oral consumption. It is also part of vitamin B complex tablets. This method is acceptable unless someone has problems absorbing it through the stomach.

Some people’s stomachs can’t process cobalamin properly. By placing a dissolvable tablet under the tongue, it goes directly into the bloodstream.


Shots are administered only by a medical professional who injects them intramuscularly. It is injected straight into the bloodstream to supply cobalamin to people who cannot absorb this vitamin through the intestine. Injections treat and prevent a lack of it caused by pernicious anemia.

Injections come in a solution (hydroxocobalamin) to inject into a muscle or just under the skin. A healthcare provider injects it. People generally receive injections once a day for the first 6-7 days of treatment. As your red blood cells return to normal, they probably will receive the medication every other day for a few weeks and then every 3-4 days for 2-3 weeks. After the anemia, they may receive the drug once a month to prevent relapse. Shots also can be given to test how well the body will absorb it.

Always talk to your doctor about using this drug for your condition.

Sleep Disorders

This nutrient is a possible treatment for sleep-wake rhythm disorders. According to NIH research, most outcomes were successful, of two patients suffering from different sleep-wake rhythm disorders for many years. One patient was a 15-year-old girl suffering from a free-running sleep-wake rhythm. After being administered cobalamin, her sleep-wake rhythm got much better. However, after two months of stopping it, her sleep disorder started again. The other patient was a 55-year-old man with delayed sleep phase syndrome. Cobalamin at the daily doses of 1.5 mg, his sleep-wake rhythm disorder got better. The positive therapeutic effect continued for more than six months while on cobalamin.

Age-Related Macular Degeneration (AMD)

Research indicates it may help a severe eye disease called age-related macular degeneration (AMD). In addition, some research shows that taking it with other vitamins, including folic acid and vitamin B6, may help prevent it.

Anti-Aging Factor

Telomeres are an essential part of human cells that affect how our cells age.

According to, “Researchers found that women who use vitamin B12 supplements have longer telomeres than those who don’t…”.


Here are some possible reasons why Cobalamin deficiency has become so widespread:

  • As the body ages, it often loses the ability to absorb this nutrient

The Intrinsic Factor (see above) is vital to the utilization of cobalamin. Some people’s bodies, especially those of older adults, gradually lose this bodily function over time. Without a healthy Intrinsic Factor, little if any vitamin B12 gets into the bloodstream. Some people have difficulty absorbing the nutrient, such as having an autoimmune condition, taking medications, celiac disease, or consistently drinking too much alcohol.

  • There is a growing population of health-conscious people who are eating less meat, fish, and chicken.

Vegetarians and vegans eat no animal protein products, which is the number 1 source of B12. It is because other health-conscious people have cut way back on their meat consumption, and chicken has inadvertently reduced the primary source of cobalamin. Also, proteins are expensive, so they are often omitted by people to conserve money.

Some people are just not aware of the vital role in their “Health, Healing and Happiness.”

Vitamin B Complex supplements may not work

  • Although many people are taking this supplement, the cobalamin may not get adequately absorbed due to the “Intrinsic Factor,” so they are not getting enough though they were getting from them.

Pernicious Anemia

Pernicious anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. There are many types of anemia. Pernicious anemia decreases red blood cells that occur when the intestines cannot properly absorb them. Severe or long-lasting pernicious anemia can damage the heart, brain, and other organs in the body. Pernicious anemia can also cause other problems, such as nerve damage, neurological problems (memory loss), and digestive tract problems. People who have pernicious anemia also may be at higher risk for weakened bone strength and stomach cancer.


It was first isolated in 1948 by American chemist Karl Folkers and British chemist Baron Alexander Todd.

The discovery of this nutrient, its role in metabolism, and its effects occurred in phases. As a result, it was the subject of two separate Nobel Prizes. However, the valuable contribution of clinical reports and studies of patients with pernicious anemia throughout the 19th century resulted in enough clinical definition to allow Minot and Murphy to put together the first hallmark study on treating the condition, leading them to a Nobel Prize.

About Getting Tested

A simple blood test, either from a physician or ordering a home testing kit, can help anyone determine whether you should supplement your diet. The currently accepted deficiency level is 148 pmol/L (picomole per liter). However, according to Katherine Tucker at the University of Boston, “Some people exhibit neurological symptoms in the higher range. There is some question as to what the clinical cutoff for deficiency should be”.

Cobalamin – Alcohol & Substance Abuse

This nutrient may very well help in both preventing and treating drug addiction and alcoholism. Unfortunately, certain health conditions can make it difficult for your body to absorb enough of it, including chronic alcoholism. Today, more and more drug and alcohol treatment programs incorporate vitamins and other nutrients into their recovery program. Research indicates a deficiency in B vitamins can cause a craving for alcohol. Therefore, taking a supplement can reduce the desire to consume alcohol. Using alcohol depletes vitamin B. Wernicke-Korsakoff Syndrome (wet brain) due to thiamine (vitamin B1) deficiency.

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