Vitamin B12 Weight Loss Connections + Reasons You Don’t Want to Be Low

Vitamin B12 is needed for making healthy red blood cells, but vitamin B12 weight loss connections give this nutrient a lot more possible benefits in the body than researchers once thought.  

This water-soluble nutrient is critical for a healthy nervous system. It also helps with sexual health and for healthy red blood cell growth. A deficiency of vitamin B12 is often seen as a type of anemia called megaloblastic anemia. But vitamin B12 deficiency can hide in plain sight with many vague symptoms as I see all of the time. 

Causes of Low Vitamin B12 Levels

In this day and age, vitamin B12 deficiency is more common than ever.  This is partially because over half of Americans are on prescription medications. Some common medications rob the body of vitamin B12.  This includes diabetes medications like metformin, birth control pills, and stomach acid medications like omeprazole. 

Low stomach acid also can cause vitamin B12 deficiency. Interestingly, you need an acidic stomach to help the body absorb vitamin B12. This condition of low stomach acid is surprisingly common. 

Not to mention, poor diet quality or restrictive diets like vegetarian or vegan diets are ever-increasingly causing vitamin B12 deficiency. If you have a digestive disorder like Crohn’s disease or autoimmune conditions, you are also more likely to have a vitamin B12 deficiency as well. 

Also, conditions like gluten intolerance and celiac disease can increase the likelihood of getting vitamin B12 deficiency.  Vitamin B12 deficiency can also be present in underweight people due to malnutrition.

People also rarely eat traditional foods like organ meats as they did in days gone by. These organ meats are the highest source of vitamin B12 of all foods. 

Long-term deficiency of vitamin B12 is also present after surgery for weight loss called gastric bypass or other abdominal surgeries. 

Let’s learn about how low vitamin B12 levels also can be related to weight gain. 

Vitamin B12 Weight Loss Connection

Any nutrient that is involved in the metabolism of food into energy has a possible role in keeping your body a healthy weight. Vitamin B12 does this by helping convert carbohydrates, protein, and fat into energy in the body via the Kreb cycle. 

In fact, vitamin B12 deficiency increases the amount of fat present in all tissues according to early research. 

Because vitamin B12 helps convert food into energy, if you eat foods that don’t have vitamin B12, it will cause your body to use up its vitamin B12 stores.  For example, high-carbohydrate foods and sweet treats could potentially do this over time. 

Additionally, vitamin B12 is critical for red blood cell formation in the body.  Red blood cells carry oxygen to the tissues, which allows for proper energy for the body to exercise and function well.  Without enough vitamin B12, people may have less energy and feel less motivated to exercise and burn calories because of this. 

Vitamin B12 Supplements for Weight Loss: Does it Work?

Research now clearly demonstrates that if you have a low vitamin B12 level that it increases your risk of having a high BMI or a higher chance of being obese. What is less clear is whether or not vitamin B12 supplements help with weight loss. 

If your mom had low B12 levels while she was pregnant with you, you have increased odds of a higher body fat percentage. Sadly, low vitamin B12 levels are also related to an increased risk of preterm birth.

B vitamins may help with weight loss because they stimulate enzymes involved in energy production according to an animal study.

However, supplements of fairly large doses of oral vitamin B12 at 500 micrograms per day did not reduce body weight over a period of 2 years.  However, they were also given synthetic folate, also known as folic acid, which could have interfered with the results. An important note about this study is that people didn’t continue to gain weight, which could indicate that vitamin B12 actually was helping.  Adding a healthy diet to the B12 supplements probably would have been a more effective strategy. 

Some clinics use vitamin B12 injections as part of their medical weight-loss programs.  This would provide higher amounts of vitamin B12.  At this point in time, there is no evidence that this is an effective tool for weight loss. 

Taking vitamin B12 supplements along with other B vitamins and as part of a healthy weight management program and high vitamin B12 foods, however, is more likely to promote positive results.  

Natural Vitamin B12 Food Sources

To improve the health of your body, it’s always a good idea to get foods into your diet that are rich in vitamin B12. The best food sources include:

• Grass-finished beef liver
• Other organ meats
• Wild game
• Clams 
• Oysters
• Tuna
• Crab
• Beef steak

If you don’t regularly eat these foods or have any of the health conditions associated with poor vitamin B12 absorption as indicated above, it may be best to add a vitamin B12 supplement or a vitamin B complex to your daily routine.  You may need higher doses or vitamin B12 injections if your levels remain low. 

Ideal Vitamin B12 Levels

If you get a standard healthcare check-up, you should know that your doctor rarely checks vitamin B12 levels. However, I highly encourage you to ask your doctor or healthcare provider to check your blood vitamin B12 status if you suspect you may be low. 

While deficiency is often defined as a blood level of less than 200 pg/ml, levels less than 475 pg/ml can show signs of vitamin B12 deficiency including nerve damage.  Additionally, levels of vitamin B12 less than 550 pg/ml can result in low B12 levels in cerebrospinal fluid. So, optimal blood levels are much higher than the current reference ranges.  

Symptoms of Vitamin B12 Deficiency

The symptoms of vitamin B12 deficiency are broad and can be devastating to health. These symptoms can include but aren’t limited to anemia, fatigue, nerve damage, tingling in the fingers and toes, depression, mood changes, shortness of breath, a smooth tongue, vision changes, and digestive issues according to WebMD. 

Symptoms like these can be scary because the nerve damage caused by vitamin B12 deficiency can be permanent.

Treating a vitamin B12 deficiency often involves getting vitamin B12 shots and this sometimes needs to happen for your whole life if you have stomach and digestive issues that won’t allow you to absorb vitamin B12. 

Taking Vitamin B12 Supplements

If you want to take a vitamin B12 supplement, most health food stores carry a variety of types.  To get the best kind of vitamin B12, you should look for natural forms including methylcobalamin and adenosylcobalamin.  

While it is easier to find vitamin B12 in cyanocobalamin form, this form may be less likely to be retained in the body. Also, methylcobalamin and adenosylcobalamin have fewer side effects and are better used by the body than cyanocobalamin. Still, people with methylation issues may need to avoid methylcobalamin.  A good choice in this situation is the adenosylcobalamin form of vitamin B12. 

There is no known major toxicity of vitamin B12 supplements. This means that you can take doses of greater than 1 mg per day and still be safe. When in doubt, make sure to have your doctor re-check your vitamin B12 levels after taking supplements for a few months to see if you are absorbing it well. 

Vitamin B12 Weight Loss Verdict

If you want to lose weight, you should make sure that your diet contains plenty of vitamin B12. You should also make sure that your healthcare provider checks your vitamin B12 levels. However, don’t expect vitamin B12 to work alone in helping you lose weight.  

Your diet should include vitamin B12-rich foods to do its job in promoting a healthy metabolism.  This will also help avoid further depletion of vitamin B12 too if you avoid processed foods. Finally, make sure you review your medication list to see if any of them can cause vitamin B12 deficiency.

Vitamin B12 Weight Loss Reviews

Although there are no clear weight loss benefits for reviewers, most people who supplement the adenosylcobalamin or methylcobalamin form of vitamin B12 report dramatically improved energy, focus, and clarity.  Some people report improved calmness, reduced body tingling, and improved mood.

Reviewers also sometimes encourage starting with a smaller dose of vitamin B12. This is because some people have too much energy and even got heart palpitations when taking doses of 3000 micrograms per day. 

Vitamin B12 FAQs

Does Vitamin B12 Increase Appetite?

It might. This is because low vitamin B12 levels can cause indigestion and a poor appetite.  So naturally, improving your vitamin B12 status may increase your appetite.  However, this is not a reason to ignore a vitamin B12 deficiency. 

Can you take vitamin B12 shots at home?

Vitamin B12 injections can be taken at home if they are prescribed that way by your healthcare provider. 

Do vitamin B12 shots work better for weight loss than vitamin B12 supplements?

No evidence shows that vitamin B12 shots reduce weight over vitamin B12 supplementation. However, you may need vitamin B12 injections if your body can’t absorb vitamin B12 capsules or vitamin B12 drops.