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Does B12 increase oxygen?

Vitamin B12 is an essential vitamin that plays many important roles in the body. One common question is whether B12 can help increase oxygen levels in the blood. While there are some theoretical reasons why B12 may improve oxygen transport, the evidence for this is limited. In this article, we’ll explore the science behind B12 and oxygen, look at what studies have found so far, and discuss whether increasing B12 intake can really boost oxygen levels.

What is Vitamin B12?

Vitamin B12, also known as cobalamin, is a water-soluble vitamin that is involved in several critical processes in the body. It plays a key role in red blood cell formation, neurological function, DNA synthesis, and energy metabolism (1).

There are several forms of B12, but the active forms in human metabolism are methylcobalamin and 5-deoxyadenosylcobalamin. Dietary sources of B12 include animal products like meat, fish, eggs and dairy. It can also be found in fortified foods and supplements.

The recommended daily intake of B12 is 2.4 mcg for adults, though requirements increase during pregnancy and for those with certain medical conditions (2). Deficiency is common, especially among vegetarians, vegans and the elderly. Low B12 can cause anemia, fatigue, neurological issues and more (3).

Why Might B12 Increase Oxygen?

There are a few reasons why vitamin B12 may theoretically improve oxygen utilization and delivery:

B12 is Required for Red Blood Cell Formation

Red blood cells, or erythrocytes, are responsible for carrying oxygen from the lungs throughout the body. Hemoglobin is the protein within red blood cells that actually binds to oxygen.

B12 plays an essential role in red blood cell creation and maturation. It is needed for synthesis of hemoglobin and development of normal red cell structure and function (4).

Without adequate B12, red blood cell counts decrease and cells become enlarged. This condition is known as megaloblastic or pernicious anemia (5).

Optimizing B12 status helps promote normal red blood cell production. Ensuring sufficient numbers of healthy red blood cells may therefore allow more oxygen to bind to hemoglobin and reach tissues.

B12 May Reduce Nitric Oxide Reduction

Nitric oxide (NO) is a molecule that helps dilate blood vessels and improve circulation. Some research indicates that NO levels decrease in B12 deficiency (6).

Higher NO levels allow blood vessels to relax and widen, which improves blood flow. This effect enhances delivery of oxygen-rich blood throughout the body.

Through mechanisms still being researched, B12 may help maintain nitric oxide status and support healthy vasodilation.

B12 Deficiency Can Limit Oxygen Usage

While B12 is not directly involved in cellular oxygen utilization, deficiency hampers cells’ ability to use oxygen properly.

This is because B12 plays a crucial role in energy production. It is needed to convert carbohydrates into glucose, fat into energy, and metabolize proteins (7).

Without adequate B12 levels, cells shift their energy production pathways. This makes them less efficient at using oxygen, even when oxygen is available (8).

Correcting a B12 deficiency restores cellular metabolism and energy pathways, allowing cells to optimally utilize available oxygen again.

What Does the Research Say?

While B12 may help oxygen levels in theory, what does the scientific research indicate? Let’s review the current evidence.

Animal Studies

Some studies in rats have found benefits from B12 supplementation on oxygen utilization and exercise performance:

– One rat study gave vitamin B12 injections over 10 days. B12 improved oxygen utilization during exercise and increased physical work capacity (9).

– Another study found that 4 weeks of vitamin B12 injections increased oxygen delivery to tissues and levels of nitric oxide metabolites in rats (10).

– Research in rats with B12 deficiency found that B12 supplementation increased nitric oxide levels in the blood and restored nitric oxide metabolism (11).

However, these results have not been consistently replicated in other animal studies so far. More research is still needed.

Human Studies

Research is more limited in humans at this time:

– A study in 19 patients with pernicious anemia found that treatment with B12 improved oxygen delivery to tissues during exercise (12).

– A study in 11 healthy men observed increased plasma nitric oxide levels after 7 days of vitamin B12 supplementation (13).

– However, other studies did not find benefits. A trial in competitive cyclists found no improvement in oxygen uptake after 6 weeks of B12 injections (14).

Overall the results are quite mixed, with some studies showing benefits while others show no change. Larger, higher quality controlled trials are still needed.

Other Potential Benefits of B12 for Oxygen

While evidence is lacking that B12 directly increases blood oxygen levels in most people, maintaining adequate B12 status may still benefit oxygen delivery and utilization in other ways:

– Correcting B12 deficiency anemia – Improving anemia can increase red blood cell counts and hemoglobin to restore oxygen-carrying capacity.

– Supporting endothelial function – B12 may support blood vessel dilation through effects on nitric oxide and other mechanisms.

– Preventing elevated homocysteine levels – B12 plays a role in homocysteine metabolism. High homocysteine can damage blood vessels and restrict blood flow.

– Supporting metabolic enzymes – B12 is a cofactor for enzymes involved in cellular respiration and energy production that utilize oxygen.

– Protecting mitochondria – Mitochondria produce energy using oxygen. B12 deficiency can lead to mitochondrial dysfunction.

– Supporting lung function – B12 deficiency can cause neurological changes that impair breathing control and lung function.

So while B12 may not directly increase blood oxygen content in healthy people, it supports many processes essential for proper oxygen delivery and use.

Is There Any Risk of Increasing B12 Intake?

For the most part, vitamin B12 is considered very safe, even at high supplemental doses. Because it is a water-soluble vitamin, excess is generally excreted in urine.

However, there are some precautions to keep in mind:

– Masking B12 deficiency – Very high B12 intake may mask or delay diagnosis of a true B12 deficiency. Symptoms should not be ignored.

– Interactions with medications – B12 can interact with certain diabetes, antacid, chemotherapy and antibiotic medications.

– Increased risk of acne – There have been some links between high B12 levels and increased acne, especially for those taking supplements orally.

– Potential for hypokalemia – Large doses delivered by injection may temporarily decrease potassium levels. This is generally not a concern with oral supplementation.

Unless correcting a known deficiency, most healthy adults don’t need vitamin B12 supplements above the RDA. Always speak to your doctor before starting very high dose B12 supplementation.

The Bottom Line

So does B12 increase oxygen levels or improve oxygen utilization? The current research shows:

– B12 plays important roles in processes related to oxygen delivery and use like red blood cell function and cellular energy production.

– Animal studies suggest B12 may increase nitric oxide levels, oxygen usage during exercise, and physical work capacity.

– A few small human studies observed benefits from B12 supplementation on oxygen delivery and nitric oxide levels.

– However, other higher quality human trials have not found a clear benefit from B12 on oxygen levels in most healthy adults.

– More research is still needed to understand if B12 has a direct influence on blood oxygen content.

– Maintaining adequate B12 intake supports many aspects of oxygen delivery and utilization, though may not directly increase blood oxygen levels.

– Unless treating a known deficiency, high supplemental doses of B12 are likely unnecessary for most people.

In summary, vitamin B12 supports many essential processes related to oxygen and energy use in the body. While benefits from increasing intake are unlikely for those with normal B12 status, there are many other reasons to ensure you meet the RDA for this critical micronutrient. A balanced, whole food diet and supplements under a doctor’s guidance when needed can help maintain healthy B12 status.

Frequently Asked Questions

How much B12 should I take to increase oxygen?

There is no established dose of B12 proven to directly increase oxygen levels. Getting the RDA of 2.4 mcg per day from food and supplements may help support oxygen delivery and usage. Doses up to 100-200 mcg are unlikely to cause harm for a short period, but speak to your doctor before starting high dose supplementation.

Does B12 help you breathe better?

Low B12 levels can sometimes impair breathing control and lung function. This is because B12 is needed for proper neurological signaling. Correcting a deficiency can therefore help improve breathing and lung function. However, B12 is unlikely to improve breathing or lung function in an otherwise healthy person with normal B12 status.

Can B12 injections increase oxygen?

A few studies have found B12 injections improved exercise performance and oxygen utilization in rats. In humans, B12 injections may enhance oxygen delivery in those with B12 deficiency anemia. However, there’s little evidence that B12 injections increase blood oxygen levels in healthy people with normal B12 status. Speak to a doctor before pursuing injected B12.

Does methylcobalamin increase oxygen?

Methylcobalamin is the active form of B12 used at the cellular level. While it’s essential for oxygen utilization during energy production, there is currently no good evidence methylcobalamin supplements increase blood oxygen content. Oral methylcobalamin may support oxygen delivery and use similarly to other forms like cyanocobalamin.

Does vitamin B12 give you more energy?

B12 plays a major role in energy pathways like carbohydrate, protein and fat metabolism. Deficiency can lead to decreased energy levels, while correcting a deficiency can improve energy. However, there’s little evidence that B12 supplements increase energy in someone with adequate B12 status. Other factors like diet, exercise, medical conditions and sleep have a larger influence on energy levels.

What other vitamins help with oxygen?

Iron is crucial for oxygen delivery as it makes up part of hemoglobin in red blood cells. The antioxidants vitamins C and E can protect against oxidative damage to red blood cells and lungs. Vitamin D regulates erythropoietin which stimulates red blood cell production. Adequate B vitamins are also essential to extract and utilize oxygen during energy production.


While vitamin B12 is critical for many aspects of oxygen delivery and utilization, the evidence is still inconclusive on whether it directly increases blood oxygen levels in most healthy adults. Focus on maintaining adequate vitamin B12 levels through diet and supplementation under medical guidance when necessary. Be skeptical of claims that high dose B12 supplementation alone will significantly improve oxygen levels. More research is underway to understand B12’s roles in oxygen-related processes. In the meantime, don’t neglect the importance of B12 for overall health – just don’t expect it to be a magic bullet for increasing oxygen either.