nutrition

Can Vitamin B12 Really Help You With Weight Loss and Management?

Dr. Carla Montrond Correia ND, CNS

Medically Reviewed by

Dr. Carla Montrond Correia ND, CNS

4 min read

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Vitamin B12 is an important vitamin for many aspects of your overall health. Researchers are looking into its effects on weight management.

So, What can Vitamin B12 do for weight management?

Vitamin B12 is a water-soluble vitamin that’s necessary for many areas of your health, including in the formation of DNA and red blood cells, and the promotion of heart health, brain health, energy production, and more. You’ll find it naturally present in some foods – mostly from animal sources – and added to others. It’s also available in supplement form. Those on a vegetarian or vegan diet are especially prone to B12 deficiency.
In recent years, Vitamin B12 shots and supplements have gained popularity among people looking to lose weight. While there’s much research to back up claims about vitamin B12’s benefits for overall health, research has yielded mixed results when it comes to weight management. Proponents of B12 as a weight management supplement point to its potentially positive effects on energy levels and metabolism. Some studies have shown that those taking B12, along with B6 and chromium, experienced reductions in weight gain compared to other groups.

What impact does B12 have on metabolism?

Studies show that vitamin B12 supports homocysteine levels and helps the body with energy metabolism. One animal study examined the effect of B vitamins on rats. Compared to the control group, the rats who were administered B vitamins saw reduced weight gain and increased levels of enzymes that affect metabolism. Another animal study – this one concerning adult Wistar rats, fed a B12 restricted diet during maternal or postnatal period – found that the B12-deficient rats had gained weight relative to the control group. This finding underscores the importance of vitamin B12 to the metabolism.

Furthermore, a review of human B12 studies concluded that B12 does indeed play an important role in fat metabolism, observing that B12 deficiencies can be linked to difficulties with weight management. Still, there remains a need for additional high quality studies to determine how vitamin B12 may affect metabolism in human subjects. Ideally, further research will include randomized, double-blind, placebo-controlled studies.

Does vitamin B12 increase appetite?

Studies show that a B12 deficiency can sometimes result in a loss of appetite. If you take a B12 supplement to treat this deficiency, you may experience an increase in appetite, but that’s really a restoration of a normal level. In general, for healthy people, taking B12 neither increases nor decreases appetite.

Vitamin B-12 deficiency

What are the signs of vitamin B12 deficiency

While there’s no international consensus on how to define B12 deficiency in adults or pregnant people, there are some signs to look out for. Some symptoms of B12 deficiency include:

  • shortness of breath
  • headache
  • heart palpitations
  • fatigue
  • poor balance

There’s some agreement, though, that your B12 levels should be between 120 and 220 pmol/L, with the upper limit being between 650 and 850 pmol/L.

B12 injections and weight management

One of the most common and effective ways to increase B12 levels and treat B12 deficiency is through B12 injections. Injections typically are in the form of hydroxocobalamin, methylcobalamin, or cyanocobalamin, which are both effective at raising B12 blood levels and treating or preventing a B12 deficiency. Injections are especially beneficial because they allow the B12 supplement to bypass the digestive system and go straight into the bloodstream. Sometimes oral absorption is hindered by digestive issues. Injections are prescribed by a doctor and given into a muscle or underneath the skin in the subcutaneous layer.

Because of the effectiveness of injections at raising B12 blood levels, injections are uniquely suited to reduce your fatigue, boost your energy levels, and enhance your metabolism. Taken together, these benefits can support your weight management goals. Talk to a doctor to get a sense of your body’s B12 levels and see if B12 injections are the right course for you.

What is the best form of B12 to take?

B12 supplements are available in a variety of active forms. Care/of’s vitamin B12 supplement is formulated with three active forms of B12: methylcobalamin, adenosylcobalamin, and hydroxocobalamin. Dubbed “The Energizer” and available as a 30-day supply, our B12 supplement is made with vegans and vegetarians in mind and supports energy metabolism. All of our supplements are made with maximum absorption in mind.

Key takeaways

Vitamin B12 is a very important water-soluble vitamin, playing an essential role in many areas of your health. Its positive impact on energy and metabolism has led to greater interest in B12 as a support for weight management. While there’s some evidence to support the claim that B12 can help with weight management, more research – particularly of human subjects – is needed. Boosting your intake of vitamin B12 through foods and supplements can prevent or reverse deficiency, while improving your energy levels and fighting fatigue. If your doctor has determined that you are B12 deficient, you may be prescribed B12 injections.

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