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9 Health Benefits of Vitamin B12, Based on Science.


Vitamin B12, also known as cobalamin, is an essential vitamin that your body needs but cannot produce.

It’s found naturally in animal products, but also added to certain foods and available as an oral supplement or injection.

Vitamin B12 has many roles in your body. It supports the normal function of your nerve cells and is needed for red blood cell formation and DNA synthesis.

For most adults, the recommended daily intake (RDI) is 2.4 mcg, though it’s higher for women who are pregnant or breastfeeding (1).

Vitamin B12 may benefit your body in impressive ways, such as by boosting your energy, improving your memory and helping prevent heart disease.

Here are 9 health benefits of vitamin B12, all based on science.


1. Helps With Red Blood Cell Formation and Anemia Prevention

Vitamin B12 plays a vital role in helping your body produce red blood cells.

Low vitamin B12 levels cause a reduction in red blood cell formation and prevent them from developing properly.

Healthy red blood cells are small and round, whereas they become larger and typically oval in cases of vitamin B12 deficiency.

Due to this larger and irregular shape, the red blood cells are unable to move from the bone marrow into the bloodstream at an appropriate rate, causing megaloblastic anemia.

When you’re anemic, your body doesn’t have enough red blood cells to transport oxygen to your vital organs. This can cause symptoms like fatigue and weakness.

Summary Vitamin B12 is involved in red blood cell formation. When vitamin B12 levels are too low, the production of red blood cells is altered, causing megaloblastic anemia.

2. May Prevent Major Birth Defects

Adequate vitamin B12 levels are crucial to a healthy pregnancy.

Studies show that a fetus’s brain and nervous system require sufficient B12 levels from the mother to develop properly.

Vitamin B12 deficiency in the beginning stages of pregnancy may increase the risk of birth defects, such as neural tube defects. Furthermore, maternal vitamin B12 deficiency may contribute to premature birth or miscarriage.

One study found that women with vitamin B12 levels lower than 250 mg/dL were three times more likely to give birth to a child with birth defects, compared to those with adequate levels.

For women with a vitamin B12 deficiency and levels below 150 mg/dL the risk was five times higher, compared to women with levels above 400 mg/dL.

Summary Appropriate vitamin B12 levels are key to a healthy pregnancy. They’re important for the prevention of brain and spinal cord birth defects.

3. May Support Bone Health and Prevent Osteoporosis

Maintaining adequate vitamin B12 levels may support your bone health.

One study in more than 2,500 adults showed that people with a vitamin B12 deficiency also had lower than normal bone mineral density.

Bones with decreased mineral density can become delicate and fragile over time, leading to an increased risk of osteoporosis.

Other studies have also shown a link between low vitamin B12 levels and poor bone health and osteoporosis, especially in women.

Summary Vitamin B12 may play a vital role in your bone health. Low blood levels of this vitamin have been associated with an increased risk of osteoporosis

4. May Reduce Your Risk of Macular Degeneration

Macular degeneration is an eye disease that mainly affects your central vision.

Maintaining adequate levels of vitamin B12 may help prevent the risk of age-related macular degeneration.

Researchers believe that supplementing with vitamin B12 may lower homocysteine, a type of amino acid that is found in your bloodstream.

Elevated homocysteine levels have been associated with an increased risk of age-related macular degeneration (9, 10).

A study involving 5,000 women aged 40 or older concluded that supplementing with vitamin B12, along with folic acid and vitamin B6, may reduce this risk (11).

The group receiving these supplements for seven years had fewer cases of macular degeneration, compared to the placebo group. The risk of developing any form of the condition was 34% lower, while it was 41% lower for more severe types (11).

Ultimately, further studies are needed to fully understand vitamin B12’s role in promoting vision health and preventing macular degeneration.

Summary Maintaining adequate levels of vitamin B12 decreases homocysteine levels in your blood. This may help prevent the development of age-related macular degeneration.

5. May Improve Mood and Symptoms of Depression

Vitamin B12 may improve your mood.

The effect of vitamin B12 on mood is not yet fully understood. However, this vitamin plays a vital role in synthesizing and metabolizing serotonin, a chemical responsible for regulating mood.

Therefore, vitamin B12 deficiency may lead to decreased serotonin production, which may cause a depressed mood.

Studies support the use of vitamin B12 supplements for improving symptoms of depression in people deficient in this vitamin.

One study in people with depression and low vitamin B12 levels found that those who received both antidepressants and vitamin B12 were more likely to show improved depressive symptoms, compared to those treated with antidepressants alone.