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14 Benefits Of Vitamin B12 And Its Deficiency Symptoms

Medically reviewed by Dr. Abby Kramer, DC
14 Benefits Of Vitamin B12 And Its Deficiency Symptoms Hyderabd040-395603080 May 2, 2019

Vitamin B12 deficiency is one of the leading nutrient deficiencies on the planet (1). The nutrient supports your mood and memory, promotes heart health, and even treats skin diseases. Well, there are other ways vitamin B12 can work wonders for you. And hence, this post.

Table Of Contents

What Are The Benefits Of Vitamin B12?
What Are The Food Sources Of Vitamin B12?
What Are The Symptoms Of Vitamin B12 Deficiency?
What Is The Recommended Vitamin B12 Dosage?
What’s With The Vitamin B12 Shots? Who Needs Them?

What Are The Benefits Of Vitamin B12?

1. Boosts Brain And Nerve Health

Vitamin B12 - Boosts Brain And Nerve Health Pinit


Several studies speak of the benefits of vitamin B12 for brain health. One such study says how the vitamin can prevent brain volume loss in the elderly. Individuals taking adequate vitamin B12 had a reduced risk of brain shrinkage (2).

The nutrient also helps maintain healthy nerve cells, which can help prevent Alzheimer’s. It also produces brain chemicals responsible for better mood – and this can help treat depression, stress, and other anxiety disorders (3). As vitamin B12 also aids cell production (a process called methylation), it can help in autism treatment as well.

2. Improves Heart Health

Vitamin B12 has shown potential as a heart disease treatment. The nutrient lowered homocysteine levels by 32 percent, the high levels of which can elevate the risk of heart disease and heart attacks (4). Reports also suggest that taking vitamin B12 can not only save lives but also cut down the costs associated with expensive medical treatments.

Vitamin B12 supplementation was also found to reduce atherosclerosis and the resulting blood pressure.

3. Aids Digestion

B12 helps with the production of digestive enzymes, which promote digestive health and ensure the proper breakdown of food. The nutrient fosters the gut environment by promoting the growth of healthy gut bacteria. It also eliminates the harmful bacteria in the gut – and this prevents other digestive issues like inflammatory bowel disease.

4. Might Aid Diabetes Treatment

Though there is no direct link between vitamin B12 and diabetes treatment, the nutrient can treat diabetic retinopathy (damage of blood vessels in the eye) and neuropathy (nerve damage in the legs and feet). Vitamin B12 reduces homocysteine levels in the blood (we discussed this already), which can otherwise lead to retinopathy. It also reduces symptoms associated with neuropathy, which include numbness, pain, and a prickling sensation.

More interestingly, metformin, a commonly prescribed diabetic drug, can cause vitamin B12 deficiency. Which is why it might be a good idea to supplement it – especially so in the case of diabetes. Pernicious anemia is vitamin B12 deficiency experienced in the case of type 1 diabetes.

5. Supports DNA Synthesis

Vitamin B12 - Supports DNA Synthesis Pinit


Reports suggest that lack of vitamin B12 can eventually slow down DNA synthesis. And this leads to slower DNA replication (5). This can also result in another condition called megaloblastic anemia, which affects the division of bone marrow cells.

6. Might Aid Weight Loss

Though we need more research on this, some reports state that vitamin B12 helps the body convert fat into energy and also aids the breakdown of carbs. The vitamin can also boost your metabolism, and this, in turn, can boost weight loss.

However, please consult your doctor before using B12 for this purpose.

7. Is Good For Men’s Health

B12 has shown to improve blood circulation, and this might improve erection and treat erectile dysfunction (6). It also has been found to treat impotence.

8. Can Be Beneficial During Pregnancy

Vitamin B12 is required to create the new maternal and fetal cells and prevent neural tube defects in the newborn. It works together with folate to achieve this. A deficiency of vitamin B12 can also lead to folate deficiency, and this adversely affects pregnancy.

Lower B12 levels during pregnancy can also lead to preterm birth (7). The vitamin can also treat nausea and morning sickness, which are often associated with pregnancy.

9. Promotes Better Sleep

Vitamin B12 can ease sleeplessness as it can promote the production of melatonin – the sleep hormone. It was also used to treat individuals suffering from sleep-wake rhythm disorders (8).

Deficiency of B12 can also be linked to insomnia. The vitamin regulates sleep patterns, the absence of which can cause sleep troubles.

10. Can Treat Fibromyalgia

Some studies suggest that low levels of vitamin B12 can lead to fibromyalgia and even chronic fatigue syndrome. Other research also links fibromyalgia to higher levels of homocysteine in the blood – which, as we have seen, can be countered by adequate levels of vitamin B12.

Studies have also shown vitamin B12 injections to work as an analgesic, thereby aiding treatment of fibromyalgia (9).

11. Cures Tinnitus

Vitamin B12 - Cures Tinnitus Pinit


According to one Indian study, vitamin B12 supplementation can improve symptoms of tinnitus (10). Deficiency of vitamin B12 has been linked chronic tinnitus and noise-induced hearing loss.

12. Might Prevent Mosquito Bites

Though we don’t know if it can ease mosquito bites, vitamin B12 has been found to repel mosquitoes altogether. It is known to exude a mosquito repellent smell. However, we suggest you talk to a specialist before using it for this purpose.

13. Can Treat Skin Diseases

Vitamin B12 can also help treat some serious skin ailments. One study found that a vitamin B12 cream could reduce the extent and severity of eczema. You can get the cream from a pharmacy. Simply apply it to the affected areas twice a day. Or best, do as your doctor suggests. B12 also decreases inflammation and its side effects, and this is one reason it can counteract eczema.

Vitamin B12 was also found to reduce shingles pain. One report states that taking 1000 mcg of vitamin B12 on a daily basis can help treat the condition. However, recommend you check with your doctor before using it.

Oral treatment with vitamin B12 was also found to treat vitiligo. Studies suggest that folic acid and vitamin B12, along with sun exposure, can induce repigmentation (11).

Vitamin B12 might also help fight cellulite, although studies are limited on this.

14. Boosts Hair Growth

Vitamin B12 helps in the formation of red blood cells, which, in turn, boost hair growth. At the base of hair follicles, we have tiny blood vessels that connect to the roots of each hair strand. These blood vessels carry oxygen to the hair, thereby boosting hair growth and preventing hair fall.

We are done with the benefits. All good. But hey, which foods are rich in this vitamin?

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What Are The Food Sources Of Vitamin B12?

Following are some of the best food sources of the vitamin:

  • Beef and chicken liver (3 ounces contain 3,375% RDA of the vitamin)
  • Salmon (A 108-gram filet contains 821% RDA)
  • Tuna (3 ounces contain 385% of the RDA)
  • Organic yogurt (1 container of 170 grams contains 53% of the RDA)
  • Raw milk (1 cup contains 41% of the RDA)
  • Lamb (3 ounces contains 34% of the RDA)

Including these foods in your diet can help you meet your regular vitamin B12 requirements. But what if you don’t? How do you know you are deficient in this vitamin?

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What Are The Symptoms Of Vitamin B12 Deficiency?

Following are some of the most common symptoms of the deficiency:

  • Muscle aches
  • Weakness/chronic fatigue
  • Poor memory
  • Dizziness
  • Anxiety and mood swings/depression
  • Heart palpitations
  • Nausea and abdominal cramping
  • A poor appetite

Taking adequate vitamin B12 can help you avoid these symptoms. Oh wait, what does ‘adequate’ mean?

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What Is The Recommended Vitamin B12 Dosage?

This table should help you with the details:

Age Group
0 to 6 months
8 ounces
7 to 12 months
0.5 mcg
1 to 3 years
0.9 mcg
4 to 8 years
1.2 mcg
9 to 13 years
1.8 mcg
14 years and older
2.4 mcg
Adult and adolescent pregnant females
2.6 mcg
Adult and adolescent lactating females
2.8 mcg

That’s about it. You take the right foods, and you are good to go. Or are you?

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What’s With The Vitamin B12 Shots? Who Needs Them?

These are the synthetic versions of the vitamin. You can take vitamin B12 from foods or acquire the vitamin from a man-made version of the nutrient – known as cyanocobalamin.

Vitamin B12 shots are nothing but injections containing very high amounts of cyanocobalamin. These shots can quickly boost the vitamin B12 levels in the individual.

And who needs them? These shots are available only by prescription, which means a clinical diagnosis is a must. You can’t (and shouldn’t) administer the shots by yourself without the advice of a doctor or nutritionist.

Only if you are severely deficient (or are at risk), do you need these shots. And that too, after consulting your health care provider. The following factors can increase the risk of vitamin B12 deficiency:

  • Smoking
  • Alcohol abuse
  • Sticking to a vegetarian or vegan diet
  • Aging
  • Thyroid disorder
  • People on certain diabetes medications
  • Gastrointestinal disorders like Crohn’s disease
  • Surgical removal of parts of the stomach

One major benefit of vitamin B12 shots is that they bypass the stomach and are directly absorbed into the bloodstream. Hence, in case you have gastrointestinal issues or had stomach surgeries, these shots could be a better option over oral supplements.

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The B vitamins are a powerful pack. They are quite vital for optimal health. And one of them is vitamin B12, which you ought to include in your diet. Though severe deficiency of vitamin B12 is very rare (as your liver stores years’ worth of vitamin B12), it is still important we are conscious about its intake.

Tell us how this post has helped you. Simply leave a comment below.

Expert’s Answers For Readers’ Questions

Is vitamin B12 water-soluble?

Yes, B12, just like other B vitamins, is water-soluble. This simply means that having an overdose of vitamin B12 is highly unlikely – as it dissolves in water, and the remaining amount is passed out through urine.

What is the best time to take a vitamin B12 supplement?

In the mornings, after breakfast. Or you can take it during lunch.

Is too much vitamin B12 bad for you?

Not really. As we discussed, B12 is a water-soluble vitamin. But still, you can keep your dosage as per the recommended levels, or as directed by your health care provider.


1. “Vitamin B12 deficiency as a worldwide problem”. US National Library of Medicine.
2. “Vitamin B12 boasts brain benefits”. WebMD.
3. “Vitamin B-12 and depression…”. Mayoclinic.
4. “Folic acid, vitamin B12 show…”. University of California San Francisco.
5. “Megaloblastic anemia”. Univeristy of Virginia.
6. “Homocysteine and vitamin B12”. US National Library of Medicine.
7. “Maternal vitamin B12…”. US National Library of Medicine.
8. “Vitamin B12 treatment for…”. US National Library of Medicine.
9. “Response to vitamin B12 and…”. US National Library of Medicine.
10. “Therapeutic role of vitamin B12…”. US National Library of Medicine.
11. “Improvement of vitiligo…”. US National Library of Medicine.

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Ravi Teja Tadimalla

Ravi Teja Tadimalla is a Senior Content Writer who specializes in writing on Health and Wellness. He graduated from SRM University, Chennai, and has been in the field for well over 4 years now. His work involves extensive research on how one can maintain better health through natural foods and organic supplements. Ravi has written over 250 articles and is also a published author. Reading and theater are his other interests.