One of the most essential vitamins impacting our overall physical health is vitamin B12. Unfortunately, humans do not naturally produce vitamin B12, so we have to get it from the foods that we eat. While most food sources of B12 are animal foods, there are also some plant foods that can help provide enough B12 needed to keep your body in good health. 

Why is vitamin B12 important?

Vitamin B12 is an essential vitamin that is needed in order for the body to function properly. It affects many different processes and functions in the body, but since the body is not capable of manufacturing the vitamin, we must obtain B12 through the foods that we eat. 

Vitamin B12, sometimes referred to as cobalamin, plays a role in making DNA and keeping the blood cells and nerves healthy and properly functioning. Without enough vitamin B12, we not only miss out on all of the wonderful health benefits associated with vitamin B12, we may also experience serious and uncomfortable symptoms associated with a vitamin B12 deficiency. 

What health benefits are associated with vitamin B12?

The health benefits of vitamin B12 are numerous, and reading through them, it becomes readily apparent why a vitamin B12 deficiency is so problematic and dangerous (1). Health benefits associated with vitamin B12 are discussed below (1).

Red Blood Cell Formation and Production

The body needs vitamin B12 in order to produce red blood cells efficiently and effectively. Without enough vitamin B12, fewer red blood cells are produced, and the blood cells that are produced are improperly shaped. While normal red blood cells are small and round in shape, red blood cells produced during a vitamin B12 deficiency are larger and shaped like an oval. This abnormal shape and size prevents the red blood cells from moving into the bloodstream from the bone marrow quickly enough, which causes a condition called megaloblastic anemia.

Supports Bone Health

Vitamin B12 is linked to healthy bones, and low levels of vitamin B12 are linked to reduced bone mineral density (2). When bone mineral density levels are low, the bones are predisposed to becoming fragile over time. Studies have linked low vitamin B12 levels to poor bone health in women, especially as they age. When consumed at appropriate levels, vitamin B12 helps support bone health and the formation of strong bones.

Improves Pregnancy Health

In order to have a healthy pregnancy, women must take in adequate amounts of B vitamins, which helps the brain and nervous system of the fetus to develop properly. Without enough vitamin B12 during the early stages of pregnancy, there is an increased risk of birth defects, and vitamin B12 deficiency also increases the likelihood that a woman will experience premature delivery or miscarriage (3).  

Supports Eye Health

Vitamin B12 plays an important role in eye health and can help support eye function even through aging. It is believed that vitamin B12 lowers homocysteine levels, which is an amino acid that is associated with an increased risk of age-related macular degeneration when found in elevated levels in the body. 

Supports Mental Health and Mood

Serotonin, one of the chemicals in the brain that is responsible for regulating our moods, is synthesized and metabolized in part by vitamin B12. When we don’t consume enough vitamin B12, our bodies produce less serotonin, which can cause changes in mood. People with a vitamin B12 deficiency are twice as likely to experience severe mood changes as people who receive adequate levels of the vitamin (4). 

Supports Energy Levels

It’s common for people with a vitamin B12 deficiency to report feelings of tiredness or weakness due to low levels of red blood cells and oxygen in the body. People who receive adequate amounts of vitamin B12 as part of their daily diets are likely to experience greater feelings of energy than those who are deficient in the vitamin, and one study showed that adding vitamin B12 supplements or otherwise increasing vitamin B12 intake in patients with a significant vitamin B12 deficiency can improve a person’s feelings of energy (5).

What are the signs and symptoms of a vitamin B12 deficiency?

Diagnosis of a vitamin B12 deficiency can be complex, as some of the signs and symptoms may not appear for years and can be easily confused with other deficiencies, such as folate deficiency. Symptoms associated with a vitamin B12 deficiency include (6):

• Fatigue and weakness, which occur as a result of the body not having enough red blood cells to transport oxygen throughout the body.
• Pale or jaundiced skin due to the lack of strong and normally sized red blood cells.
• A feeling of pins and needles that can result from nerve damage caused by a lack of properly produced myelin to protect and insulate the nerves.
• Inflamed tongue, called glossitis, and mouth ulcers that cause inflammation and pain in the tongue and mouth. An inflamed and swollen tongue marked by long straight cuts or lesions is a common early sign of vitamin B12 deficiency.
• Mobility changes, including differences in how you move and walk, that are caused by damage to the nervous system that occurs as a result of the myelin deficiency.
• Blurred or disturbed vision that results from damage to the optic nerve in the eyes.
• Feeling out of breath or dizzy as a result of the body not getting enough oxygen from red blood cells.
• High temperature, although rare, can also be caused by a vitamin B12 deficiency.
• Changes in mood, including depression and dementia, due to interference in the brain's signals and damage to the brain tissue caused by high levels of homocysteine.

Who is at risk of a vitamin B12 deficiency?

While anyone can suffer from a vitamin B12 deficiency, some groups of people are at a higher risk than others. Groups at increased risk for vitamin B12 deficiency include (6):

• Elderly people
• People who take metformin for diabetes
• People taking antacids for heartburn for an extended period of time
• People who have had surgery to remove the portion of the small intestine that absorbs vitamin B12
• People who follow a strict vegan or vegetarian diet

How much vitamin B12 do I need each day?

The amount of vitamin B12 a person needs each day depends primarily on their age, but certain medical conditions and medications can also affect the amount of vitamin B12 needed. Most adults and teenagers aged 14 and older need 2.4 micrograms (mcg) per day, although pregnant women should receive 2.6 mcg and breastfeeding women should consume 2.8 mcg per day. Infants up to 6 months of age should receive 0.4 mcg, while babies should receive 0.5 mcg between the ages of 7 and 12 months. Children between the ages of 1 and 3 should receive 0.9 mcg, and kids between the ages of 4 and 8 should receive 1.2 mcg. From ages 9 to 13, children should receive 1.8 mcg.

What about a plant-based source of B12?

Vitamin B12 is only found naturally in animal sources like meat, cheese, eggs, yogurt, and other dairy products. Recognizing the need to diversify food sources of vitamin B12, particularly for those who do not eat animal products, vitamin B12 can now be found in some vegan sources that have been specially fortified to be a reliable source of the vitamin. Plant-based sources of vitamin B12 include (7):

• Fermented quinoa
• Fortified plant-based milk
• Fortified breakfast cereals and other whole grain products
• Fortified nutritional yeast
• Fortified meat substitutes
• Fortified vegan spreads
• Tempeh, and some other soy products like soy milk 

If you rely on plant-based foods for your source of vitamin B12, it is extremely important to read the labels of the foods that you are purchasing, as not all breakfast cereals or plant-based milks have been fortified with the vitamin. 

Whole food supplements such as GEM also offer a good source of vitamin B12 while still fitting within a vegan diet, and can offer additional essential nutrients too that most people tend to lack, such as vitamin D. 

People with significant vitamin B12 deficiencies may need to receive a vitamin B12 injection or supplement their diet with higher doses of vitamin B12 in the form of capsules. Always consult your physician if you have concerns about a nutrient deficiency, as well as before adding in a new supplement to your daily wellness routine. 

By the Numbers:

• 2.4: Number of micrograms of vitamin B12 that the average adult needs in a day (8). 
• 40: Percentage of the population that is estimated to have a vitamin B12 deficiency (9).

Fun Facts:

• Unlike other vitamins and minerals, a higher than necessary intake of vitamin B12 is not associated with any negative side effects. Therefore, there is no tolerable upper intake level set for vitamin B12 (10).
• Vitamin B12 is only found naturally in foods of animal origin. It is found in some fortified plant-based sources.