The 10 Proven Health Benefits of Vitamin B12

We are all aware that we need various vitamins and minerals to be healthy. Most of us try to follow a healthy diet that offers us such nutrients. But surprisingly, despite following healthy diets, vitamin B12 deficiency remains quite common among us, especially the vegans and vegetarians.

Our body cannot make its own vitamin B12, so it has to be absorbed from the diet. Vitamin B12 is vital for making red blood cells that carry oxygenated blood to various parts of the body. It is required for the formation of nerves, in DNA synthesis and for a whole host of other functions.

Vitamin B12 deficiency is a serious issue that causes us to feel weak and tired due to anemia resulting from the lack of red blood cells. As the deficiency worsens, our nerves may get damaged. Eyesight blurs if optical nerves get damaged, and even our taste buds get affected.

But some people can’t absorb vitamin B12 even if they eat the right foods due to the loss of gastric intrinsic factor which is necessary for absorbing this vitamin. The deficiency of vitamin B12 is also common among the elderly population due to reduced secretion of stomach acid.

So what should we do? How do we ensure we get adequate vitamin B12 in our diet and also that it is properly absorbed in our body? Read on to find these answers and to understand more about this vital nutrient, its benefits and much more.

What is Vitamin B12?

Vitamin B12 is a nutrient that is present in every cell of the human body and helps in the breakdown of food and its conversion into energy. It helps to make DNA the genetic material that contains all the instructions needed for the development, functioning, growth, and reproduction of all organisms. It aids in the development of red blood cells in the bone marrow and is important for the functioning of the nervous system.

Vitamin B12 is one of the eight B vitamins and has a complex structure. Vitamin B-12 is water-soluble and travels through the bloodstream. Unwanted vitamin B12, if any, is passed out in the urine, so you don’t have to worry about overdosing on this nutrient.

This vitamin can be synthesized only by certain bacteria found in the gut flora of animals. Cobalt, which is rare biochemically, is found in vitamin B12. Vitamin B12 is also called cobalamin or cyanocobalamin (for over the counter supplement) due to this cobalt-containing chemical structure.

The Food Sources of Vitamin B12

Vitamin B12 is easily available in a non-vegetarian diet as poultry, eggs, fish, chicken, and meat are good sources of this nutrient. Beef liver and clams are considered the best sources.

But a vegan diet lacks it as plant-based food sources do not have any vitamin B12 in them. Since milk and dairy products do contain vitamin B12, vegetarians may get some B12, but usually, this is not sufficient for their body’s requirements.

Dietary supplements and foods fortified with vitamin B12 are a must for vegans and vegetarians to ensure they get adequate amounts of it. Most multivitamin supplements contain vitamin B12. It is available in sublingual forms which can be dissolved under the tongue. Vitamin B12 can be administered in an injection form or as a nasal gel, but you need prescriptions for these.

The 10 Proven Health Benefits Of Vitamin B12

Once you increase your intake of vitamin B12, from food sources and/or dietary supplements, you may experience many surprising health benefits. Let’s take a closer look at what roles vitamin B12 plays to make us healthier:

Helps With Red Blood Cell Formation

Every minute, millions of red blood cells are produced in the body because of vitamin B12. This production is directly proportional to the amounts of B12 available in the body.

The depletion of these vitamin B12 stores causes a condition called megaloblastic anemia in which the body does not have sufficient healthy red blood cells to carry oxygen to the tissues. Without adequate B12, the red blood cells increase in size and instead of their usual small round shape, they gain a larger oval size. This makes it difficult for them to enter into the bloodstream from the bone marrow where they are produced.

A person with anemia feels tired and weak due to the lack of healthy red blood cells carrying oxygen. This condition can remain for a short or long period of time and may range from being mild to severe anemic conditions.

Summary: Vitamin B12 plays an important role in the formation of red blood cells that carry oxygen to other cells in the body. The deficiency of vitamin B12 causes megaloblastic anemia which is characterized by fatigue and weakness.

Vitamin B12 May Prevent Osteoporosis


Our bodies are constantly replacing our bone tissues, replacing the old with the new. Osteoporosis results when the body loses bone faster than it’s being replenished or the newly formed bone structure is weak. Vitamin B12 is required for DNA synthesis and bone formation and any deficiency of this vitamin can cause your bones to become porous and weaker. Vitamin B12 supplementation may be effective in promoting bone health. especially for the elderly.

A 2004 US study from Tufts University in Boston noted that vitamin B12 may contribute to bone health and prevent osteoporosis. The study was conducted to ascertain the relationship between bone mineral density (BMD) and vitamin B12. 2576 adult participants undertook the test. As we age bone mineral density decreases leading to the risk of osteoporosis setting in. The researchers noted that decreased vitamin B12 levels were a risk factor for low BMD.

Summary: Vitamin B12 is required for the formation of strong bones and its deficiency may cause osteoporosis leading to weak and brittle bones.

May Promote Vision Health

Vision Health

Age-related macular degeneration (AMD) is the primary cause of permanent loss of vision among people who are 50 years and above. This results from the deterioration of the central part of the retina called the macula. In industrialized countries, 25-35 million people are affected by this condition. This medical condition is common among the elderly population and sufficient levels of vitamin B12 may help reduce this risk. AMD occurs in two stages known as early and late age-related maculopathy.

Vitamin B12 along with vitamin B6 and folic acid are important regulators of homocysteine. Homocysteine is an amino acid that is used to make proteins. High levels in the blood may be an indication of a vitamin deficiency. It may also show the possibility of heart disease or a rare inherited disorder. The risk of the cardiovascular condition also may be displayed by patients of AMD. Researchers are of the opinion that B12 supplementation may reduce the levels of homocysteine in the blood.

A trial was conducted to observe the occurrence of AMD among 5000 women who were 40 years or older with preexisting cardiovascular disease. They received a combination of folic acid, vitamin B6 and vitamin B12. After 7 years and 3 months of treatment, 55 cases of AMD were reported in the group that had the vitamins and 82 cases of AMD were noted in the placebo group. This study shows evidence that daily intake of folic acid, B6 and B12 may reduce the occurrence of AMD.

Summary: Research has shown that a daily intake of vitamin B6, B12, and folic acid may help prevent AMD.

Vitamin B12 May Promotes Skin Health

Skin Health

Adequate intake of vitamin B12 is necessary for the health of your skin, hair, and nails. Vitamin B12 has a complex relationship with the skin. Since our skin is constantly getting renewed, vitamin B12 is essential for the production of new cells, its deficiency can result in many skin-related health issues such as hyperpigmentation, hair and nail changes and even glossitis, which is the inflammation and swelling of the tongue.

Lack of vitamin B12 may also contribute to vitiligo, a disease that causes the loss of skin color in patches. B12 deficiency may also cause angular stomatitis which is characterized by inflamed and cracked corners of the mouth.

Vitamin B12 supplementation may help in preventing acne, rashes, dry and flaky skin, cracked lips and even reduce wrinkles, in those who are deficient in this vitamin. If you already have sufficient B12, then the supplementation may not have any effect. Studies have found that hyperpigmentation due to vitamin B12 deficiency was reversed on treatment with intramuscular cyanocobalamin (B12).

Summary: Vitamin B12 is necessary for maintaining the health of the skin. B12 supplementation may help reverse hyperpigmentation that results from vitamin deficiencies.

May Improve Mood And Reduce Symptoms Of Depression


Vitamin B12 supplementation may help improve mood since it helps in the synthesis of serotonin, a neurotransmitter that is required for mood regulation. The deficiency of B12 vitamin may cause you to feel depressed. Even in cases of severe depression, vitamin B12 was found to enhance the effects of other antidepressants.

A 2013 study, from the Penn State College of Medicine, Hershey, USA, observed the effect of antidepressants on 199 depressed patients. The researchers found that the combination of B12 with antidepressants was more effective than using anti-depressants alone. Another study from the National Institute on Aging, Bethesda, USA, noted that older women with vitamin B12 deficiency were doubly at risk of developing severe depression.

Summary: Vitamin B12 aids in the production of serotonin and the combination of B12 with antidepressants is more effective in reducing depression than using only antidepressants.

May Help Improve Memory

Enhance Memory

Increasing memory loss is a common occurrence among the elderly. As we age, we all slowly lose some brain cells. But brain atrophy, which may result from disease or injury, speeds up this process and can affect any part of the brain. This loss of neurons in the brain may cause memory impairment or even dementia. B12 supplementation may help slow down the deterioration and improve memory loss.

A 2106 study, from Oxford University in the UK, using patients in the early stages of dementia observed that the administration of vitamin B12 along with omega-3 fatty acids slowed the decline of the mental faculties among these patients.

266 participants, who were 70 years of age or above, were given vitamin B12, vitamin B6, and folic acid, or placebo for 2 years. The study found that the combination of these nutrients worked to slow down the rate of cognitive and clinical decline only when the patients had adequate omega-3 plasma concentration. If their omega-3 concentration was low, the treatment has no effect leading the researchers to conclude that the combination of B-vitamins, including B12, and omega-3 fatty acids may help slow down the progression from mild cognitive impairment to Alzheimer’s disease.

Summary: Supplementing with a combination of vitamin B12 and omega-3 fatty acids may help slow down the deterioration of brain cells and improve memory loss.

Vitamin B12 May Reduce Fatigue and Boost Energy Levels

Boost Energy Levels

If you experience unexplained fatigue, the cause may be a vitamin B12 deficiency. B12 supplementation by itself does not boost energy levels in healthy individuals who have adequate levels of B12. The extra B12 just gets eliminated from your body with your urine as B12 is a water-soluble vitamin.

Depression and fatigue were studied in lacunar stroke (stroke resulting from the blocking or closing of a blood vessel) patients and its association with vitamin B12. A self-report questionnaire was handed to about 40 people who had suffered a lacunar stroke the first time. Those with a deficiency of vitamin B12 reported higher fatigue levels and symptoms of depression than those who were not lacking in the vitamin.

The study suggested an association between vitamin B12 and the extent of fatigue and depression among lacunar stroke patients. Thus vitamin B12 supplementation may help improve the quality of like of such patients by boosting their energy levels and alleviating depression.

Summary: Deficiency of vitamin B12 may cause fatigue and its supplementation may help boost energy in such individuals.

Vitamin B12 as a Cyanide Antidote

Exposure to a number of cyanide forms can cause cyanide poisoning. The early signs are headache, dizziness, fast, heart rate, shortness of breath and vomiting. It may lead to seizures, slowing of heart rate, low blood pressure, loss of consciousness and heart attack.

A large amount of hydroxocobalamin, a form of vitamin B-12  may be given intravenously, in an emergency to treat cyanide poisoning. The hydroxocobalamin ligand is displaced by the cyanide ion and the ensuing B12 complex leaves the body through urination. Hydroxocobalamin has been used by French doctors since 1970 for treating critical cases of cyanide poisoning.

Summary: A form of vitamin B-12 known as hydroxocobalamin may be used intravenously, in an emergency, to treat cyanide poisoning.

Vitamin B12 and Neurodegenerative Disorders

The levels of vitamin B12 in our bodies are dependant upon how much is acquired, secreted and absorbed and excess amounts, if any, pass out through the urine. The deficiency of vitamin B12 among the elderly has been associated with neurodegenerative disorders such as Alzheimer’s disease.

A 2013 study from the Cardiff University, Wales, United Kingdom noted low levels of this vitamin in the cerebrospinal fluid of Alzheimer’s patients. The researchers observed that B12 deficiency is also associated with other neurodegenerative disorders such as multiple sclerosis, dementia, and Parkinson’s disease and.

Chronic neuroinflammation and oxidative stress are seen in all such medical conditions which, in turn, may compromise B12 metabolism. Vitamin B12 supplementation with emphasis on its proper absorption may help in slowing the progress of such diseases

Summary: Vitamin B12 deficiency is associated with neurodegenerative disorders such as Alzheimer’s disease and its supplementation may help slow down the disease progression.

Vitamin B12 is Required for a Healthy Pregnancy

Healthy Pregnancy

Though folic acid supplementation is given more importance in the initial months of pregnancy for preventing neural tube defects in the fetus, vitamin B12 has also been found to play a vital role in the development of the brain and spine of the growing fetus.

This makes it evident that vitamin B12 deficiency in pregnant women may increase birth defects in their babies, such as neural tube defects wherein their brain and spinal cord have defects. This usually happens in the first month of pregnancy often when a woman may not even be aware that she is pregnant. Sufficient stores of B12 before pregnancy will help the unborn child receive this vital vitamin during its initial stages of development.

Summary: Sufficient levels of vitamin B12 along with folic acid supplementation greatly reduces the risk of neural tube defects in the fetus during pregnancy.

What Happens When B12 Vitamin Is Insufficient

The deficiency in vitamin B12 may cause weakness, fatigue, difficulty in bowel movement, appetite loss and megaloblastic anemia where the bone marrow produces abnormally large red blood cells that are underdeveloped. Tingling sensations and numbness occurs in the hands and feet.

Vitamin B12 deficiency can cause other symptoms like depression, confusion, poor memory, dementia and soreness of the mouth and tongue. The depletion of vitamin B12 in your body can also cause harm to your nervous system. Once the deficiency is noted, it should be treated at the earliest with B12 supplements.

The signs of B12 deficiency in infants are difficulties in movement, delayed milestones and the observation of large red blood cells in blood tests. Folic acid supplementation may mask the deficiency of vitamin B12. It will not halt the progressive damage to the nervous system which can occur if sufficient vitamin B12 is not administered. Vitamin B12 deficiency can usually be resolved with oral supplementation of B12 or intramuscular injections.

The Mechanism Of Vitamin B12 Absorption

Even if you consume adequate amounts of vitamin B12, deficiency can still occur due to impaired absorption. Reduced stomach acid production in elderly people is one of the most common causes of reduced vitamin B12 absorption. Those with gastrointestinal disorders such as Crohn’s or celiac disease may also face this issue.

Normal functioning of the stomach, pancreas and small intestine are necessary for the absorption of vitamin B12. The stomach acid and enzymes free the vitamin B12 from the protein it is attached to in the food source and then it binds with another protein known as the intrinsic factor (IF) which is produced by your stomach cells. This enables the B12 to be absorbed into our bodies. Calcium supplied by the pancreas helps the final part of the small intestine (ileum) to absorb the B12 vitamin.

You can do a medical check-up to confirm whether you have a vitamin B12 deficiency. In people suffering from pernicious anemia, the intrinsic factor required to absorb vitamin is not produced in the body. To treat this, shots of vitamin B12 are directly injected into the muscle daily or weekly until the level of vitamin B12 in your blood is sufficient.

The Dosage and Side Effects of B12 Supplements

No adverse side effects have been linked to a large consumption of vitamin B12 through food or supplements. No tolerable limit has been set by the US Food and Nutrition Board. Unlike vitamin A or D which are toxic in large doses, vitamin B12 has been found to be safe in large quantities as the excess is flushed out of the body through urine output.

Supplements that offered over 1000 times the recommended vitamin B12 intake was found to have no major side effects. 2mg of vitamin B12 orally or 1mg via intramuscular injections have been used for the treatment of pernicious anemia without any side effects. A 2008 study noted that only 9.7 mcg was absorbed by the body when a 500 mcg dose of vitamin B12 was administered, which is just about 2%.

The Final Note

Vitamin B12 is vital to the body for a number of functions. It is required for the production of oxygen-carrying red blood cells. So its deficiency can lead to megaloblastic anemia resulting in fatigue and weakness.

Vegans and vegetarians should ensure that they consume sufficient quantities of this essential nutrient from fortified food sources or supplements as it is lacking in plant-based sources.

A varied diet, that includes animal-sourced foods such as chicken, eggs, and fish, is an adequate source for those under 50 years of age to have their daily dose of vitamin B12. It is recommended for people above the age of 50 to get an added dosage from B12 supplements as absorption from food sources may decrease due to reduced stomach acid secretion.