Vitamin B12 and Weight Loss: Understanding the Connection

  • By Performance Lab
  • 5 minute read
Vitamin B12 and Weight Loss: Understanding the Connection

We’re always looking for new things to support our weight loss journeys, and while there’s certainly no shortage of fat burners and metabolism boosters on the market, it’s hard to decipher what works and what doesn’t, on top of what’s harmful and what’s healthy.

But for those looking for sustainable, long-term weight loss, quick fixes aren’t the answer.

If you’re tired of wondering why you can’t lose weight or can’t keep it off, checking out your nutritional status might be an excellent place to start, as vitamins and minerals are an essential piece of the weight loss puzzle. And there’s one, in particular, we’re interested in—vitamin B12.

From fighting fatigue and boosting energy to speeding up metabolism, we’re looking at the benefits of B12 for weight loss.

What is B12?

Vitamin B12, also called cobalamin, is an essential water-soluble vitamin that makes up part of the B complex of vitamins.

Its most well-known function is supporting red blood cell production and energy, but it’s also involved in brain development, DNA synthesis, and nervous system function, as well as serving as a co-factor for fatty acid synthesis and myelin production 1.

That’s not the only role it plays. Vitamin B12 is also needed to 2-6:

  • Maintain bone density and decrease the risk of osteoporosis
  • May protect against macular degeneration
  • May improve mood and reduce symptoms of depression
  • May protect against memory loss
  • Energy production
  • May boost heart health by reducing homocysteine levels
  • Support healthy skin, hair, and nails

For most adults consuming animal products, getting the RDI of B12 is easy, but for those following a plant-based diet or with digestive issues that interfere with absorption, supplementation may be required 7.

But one thing you may not know about B12 is that low levels can spell trouble for weight management. Let’s see how they’re connected.

B12 And Weight Loss: Is There A Link?

B12 And Metabolism

The research linking B12 to metabolic function is pretty sparse, but there is some evidence to suggest it could affect body fat and metabolism.

A 2020 review published in Nutrients looked at the pre-clinical and clinical evidence linking vitamin B12 levels and fat metabolism 8.

They found B12 plays a vital role in fat metabolism, and a deficiency could be linked to more significant fat accumulation and an increased risk of obesity. Rodent studies have noted similar results, showing that low B12 led to substantial increases in body fat and cholesterol levels 9.

On top of that, another animal study found that B12 supplementation in rats fed a high-fat diet reduced the risk of weight gain and boosted levels of enzymes involved in metabolism 10.

But if you’re looking for solid evidence linking B12 to better human metabolic function, there’s little to go on.

Deficiency And Obesity

There is substantial evidence showing that low levels of B12 are associated with an increased risk of obesity. A 2019 study published in Frontiers of Endocrinology found that sufficient levels of vitamin B12 are inversely linked to obesity 11. While there’s no concrete mechanism to explain the link, there are a few theories:

  1. Low B12 levels would retain folate as 5-methyltetrahydrofolate, which prevents the conversion of homocysteine to methionine and reduces protein synthesis and lean tissue deposition
  2. Dysfunction of adipocytes due to cellular inflammation
  3. Obesity could reduce vitamin B12 levels by decreasing dietary intake or absorption, increasing catabolism and sequestration in fat tissue
  4. Altering gut microbiota, which affects B12 metabolism

Another study of 976 people—obese, overweight, and average weight—found that B12 levels were significantly lower in overweight or obese people and slightly lower in those with metabolic syndrome 12.

Researchers concluded that low vitamin B12 was linked to obesity and overweight but wasn’t correlated with the risk of insulin resistance or metabolic syndrome.

Although there is some evidence showing that low levels of B12 may be linked to a greater risk of obesity, you also have to account for other variables that could cause weight gain—lack of sleep, stress, poor nutrition, genetics, etc.

Signs Of A B12 Deficiency

Unlike other B vitamins that are absorbed directly into the bloodstream, B12 works differently. For B12 to be absorbed, it requires the presence of a protein called intrinsic factor (IF) produced by the parietal cells of the stomach.

Intrinsic factor binds to B12, and the IF-B12 complex attaches to receptors in the gut, facilitating its absorption 7.

If your body isn’t absorbing the B12 you’re consuming, it can lead to low levels and an increased risk of megaloblastic anemia, a condition characterized by low levels of red blood cells larger than normal 13.

Megaloblastic anemia can lead to several symptoms, including 14:

  • Shortness of breath
  • Heart palpitations
  • Weakness
  • Fatigue
  • Poor balance
  • Memory issues

But low B12 doesn’t always end in megaloblastic anemia. Mild deficiencies can lead to symptoms like weakness and fatigue. Several factors do play into how much B12 your body can absorb. Some common reasons for low levels include 8:

  • Malabsorption disorders
  • Insufficient intrinsic factor
  • Age
  • Insufficient dietary intake
  • Alcohol abuse
  • Increased requirements (pregnancy, anemia, etc.)
  • Prescription medications

While a B12 deficiency isn’t likely to directly cause weight gain, it can interfere with energy levels, making staying active more challenging. If you think you’re low in B12, get your levels tested and determine the best course of action to increase them.

Where To Find Vitamin B12

For the plant-based eaters out there, getting your fill of vitamin B12 can be a challenge. Because B12 is heavily concentrated in foods of animal origin, getting enough can be tricky if you’re not supplementing. Here are some of the best sources of vitamin B12:

  • Organ meats
  • Clams
  • Sardines
  • Beef
  • Tuna
  • Nutritional yeast
  • Trout
  • Salmon
  • Milk and dairy products
  • Eggs

If you’re concerned your B12 levels may be subpar, get your levels checked and maintain proper levels with Performance Lab NutriGenesis® Multi, the world’s most innovative multivitamin.

Supplying 100% DV of 17+ essential vitamins and minerals, Multi fills nutrient gaps that may be missing in the diet with bioidentical nutrient forms complexed with cofactors to enhance absorption.

It’s ultra-clean with no synthetic or isolated nutrient forms, fillers, or additives, all encapsulated in prebiotic-infused NutriCaps® for digestive comfort.

If you’re looking for a quick energy boost without the side effects of conventional energy boosters, Performance Lab Caffeine+ is the perfect alternative.

References

  1. Ankar, A, Kumar, A. Vitamin B12 Deficiency. (Updated 2021 Jun 7). In: StatPearls (Internet). Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441923/
  2. Tucker KL, Hannan MT, Qiao N, et al. Low plasma vitamin B12 is associated with lower BMD: the Framingham Osteoporosis Study. J Bone Miner Res. 2005;20(1):152-158.
  3. Christen WG, Glynn RJ, Chew EY, Albert CM, Manson JE. Folic Acid, Vitamin B6, and Vitamin B12 in Combination and Age-Related Cataract in a Randomized Trial of Women. Ophthalmic Epidemiol. 2016;23(1):32-39.
  4. Penninx BW, Guralnik JM, Ferrucci L, Fried LP, Allen RH, Stabler SP. Vitamin B(12) deficiency and depression in physically disabled older women: epidemiologic evidence from the Women’s Health and Aging Study. Am J Psychiatry. 2000;157(5):715-721.
  5. Köbe T, Witte AV, Schnelle A, et al. Vitamin B-12 concentration, memory performance, and hippocampal structure in patients with mild cognitive impairment. Am J Clin Nutr. 2016;103(4):1045-1054.
  6. Markišić M, Pavlović AM, Pavlović DM. The Impact of Homocysteine, Vitamin B12, and Vitamin D Levels on Functional Outcome after First-Ever Ischaemic Stroke. Biomed Res Int. 2017;2017:5489057.
  7. Langan RC, Goodbred AJ. Vitamin B12 Deficiency: Recognition and Management. Am Fam Physician. 2017;96(6):384-389.
  8. Boachie J, Adaikalakoteswari A, Samavat J, Saravanan P. Low Vitamin B12 and Lipid Metabolism: Evidence from Pre-Clinical and Clinical Studies. Nutrients. 2020;12(7):1925.
  9. Ghosh S, Sinha JK, Putcha UK, Raghunath M. Severe but Not Moderate Vitamin B12 Deficiency Impairs Lipid Profile, Induces Adiposity, and Leads to Adverse Gestational Outcome in Female C57BL/6 Mice. Front Nutr. 2016;3:1.
  10. Zheng Y, Ma AG, Zheng MC, et al. B Vitamins Can Reduce Body Weight Gain by Increasing Metabolism-related Enzyme Activities in Rats Fed on a High-Fat Diet. Curr Med Sci. 2018;38(1):174-183.
  11. Sun Y, Sun M, Liu B, et al. Inverse Association Between Serum Vitamin B12 Concentration and Obesity Among Adults in the United States. Front Endocrinol (Lausanne). 2019;10:414.
  12. Baltaci D, Kutlucan A, Turker Y, et al. Association of vitamin B12 with obesity, overweight, insulin resistance and metabolic syndrome, and body fat composition; primary care-based study. Med Glas (Zenica). 2013;10(2):203-210.
  13. Ankar A, Kumar A. Vitamin B12 Deficiency. (Updated 2021 Jun 7). In: StatPearls (Internet). Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441923/
  14. Nagao T, Hirokawa M. Diagnosis and treatment of macrocytic anemias in adults. J Gen Fam Med. 2017;18(5):200-204.
[article-cta-inline category="caffeine-plus-1"][article-cta-sidebar category="multi-men-1"]