Vitamin B12 & Weight Loss: What You Should Know

Jenna Hilton
September 28, 2023

The vitamin B complex consists of eight vitamins, each with a distinct role in supporting essential bodily functions. Recent research hints at the potential benefits of B vitamins for weight loss. This is especially true for vitamin B12 (cobalamin).

This article explores the connection between B12 and weight loss and explains how to maintain optimal levels of this essential nutrient.

Vitamin B12 for weight loss

How Does Vitamin B12 Affect Weight?

Scientists speculate there is a connection between vitamin B12 deficiency and weight gain.

Your medical provider will prescribe a complete blood test with serum B12 levels, folate levels, homocysteine levels, and potentially other tests for an accurate diagnosis.

A 2013 human study observed significantly lower levels of vitamin B12 in obese and overweight patients than in healthy individuals. A later animal study had similar results, linking severe B12 deficiency to increased body fat. The research also suggests inflammation and stress significantly contribute to this deficiency.

B12 is involved in numerous bodily processes, including red blood cell production, the conversion of fat and protein into glucose (energy), and in dopamine and serotonin synthesis.

A long-term lack of B12 leads to the disruption of these essential processes, leading to:

  • Fewer red blood cells (potentially anemia) and poorer oxygen and nutrient flow, causing tiredness and fatigue.
  • Slower metabolism and faster fat accumulation.
  • Low levels of “feel-good” hormones, potentially causing decreased motivation, depression, reduced physical activity, and sleep issues.

Ultimately, these imbalances can inhibit the patient’s weight loss efforts.

Note: Learn more about how anemia causes weight issues.

Can You Use Vitamin B12 for Weight Loss?

Based on research and clinical practice, vitamin B12 may aid with weight loss if the patient has a B12 deficiency. Increasing levels may speed up metabolism and calorie burn, provide more energy, regulate sleep patterns, and balance the mood, helping patients control their appetite and exercise more.

Consult your medical provider if you experience the following symptoms as they might point to a B12 deficiency:

  • Chronic stress
  • Poor sleep
  • Tiredness and fatigue
  • Muscle weakness
  • Dizziness
  • Shortness of breath
  • Difficulty concentrating
  • Confusion
  • Depression

Your medical provider will prescribe a complete blood test with serum B12 levels, folate levels, homocysteine levels, and potentially other tests for an accurate diagnosis.

Other Vitamin B12 Benefits

Maintaining optimal vitamin B12 levels may help:

  • Prevent anemia
  • Maintain healthy brain and nerve cells
  • Preserve cognitive functions
  • Improve sleep and mood
  • Maintain optimal energy levels
  • Enhance collagen production and improve skin concerns

Medical professionals agree that supplementing vitamin B12 is generally safe, even at higher doses. The body absorbs the amount it needs and disposes of the rest. However, additional B12 may interfere with other medications and supplements so consult your healthcare provider before starting a new supplement regimen.

Sources of Vitamin B12

Most people get their daily intake of vitamin B12 through food and dietary supplements. IV therapy and vitamin injections are emerging as effective ways to restore low levels of nutrients.


Foods with significant amounts of vitamin B12 include:

  • Chicken
  • Red meat
  • Fish
  • Shellfish
  • Liver
  • Eggs
  • Milk
  • Yogurt
  • Cheese
  • Fortified foods (cereals, nutritional yeast)
  • Enriched soy and rice milk

Dietary Supplements

Vegetarians, vegans, pregnant women, and some other categories of people may not receive enough vitamin B12 through food. They are advised to take dietary supplements, available without a prescription.

The recommended dosage varies depending on the product formula, but the general dosing guideline for adults is 2.4 micrograms daily.

IV Therapy

IV therapy is a medical procedure in which patients with nutrient deficiencies and resulting health conditions can receive nutrients intravenously. Since IV therapy bypasses the digestive system and enters the bloodstream directly, nutrients are absorbed quickly and in high concentrations.

IV patients typically receive a customized cocktail of nutrients formulated specifically for their condition. The Vibrant Vitality Clinic offers Vitamin B IV therapy, which contains a mixture of B vitamins (including B12), vitamin C, and glutathione to restore energy, encourage hormonal balance, and improve a patient’s overall health.

B12 Injections

Vitamin B12 injections are used to deliver high doses of B12 directly into a patient’s bloodstream. B12 injections are recommended for patients with chronically low levels of vitamin B12 and/or in patients with gastrointestinal absorption issues such as gastric bypass surgery or Metformin use. B12 may help speed up metabolism, reduce stress, improve sleep quality, elevate the mood, and may contribute to weight loss.* Many health care professionals find it to be an effective aid in their medical weight loss programs.

Note: For more helpful advice, read our post on how to start your weight loss journey or check out our 19 practical weight loss tips.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.


Vitamin B12 is an essential vitamin that helps regulate vital bodily mechanisms, such as fat metabolism, red blood cell production, and brain and nerve function. Research and clinical experience suggest it may also regulate weight.

The healthiest way to go about losing weight (and maintaining results) is by following a medical weight loss program tailored to your current condition, medical history, and desired outcome. The medical experts at Vibrant Vitality Clinic are more than happy to work with you on achieving your goals. Contact us for more information.

Jenna Hilton
Jenna Hilton has been a practicing PA since 2009, specializing in Family, Internal Medicine and Medical Aesthetics. She attended Arizona State University where she received her Bachelor's Degree and graduated magna cum laude. She received her Master of Science degree in Physician Assistant Studies from A.T. Still University.

Jenna has been injecting neurotoxin and dermal filler since 2013. She received certification as a Master Injector in 2017 through Empire Medical in Los Angeles, California. She is currently working on a Fellowship Program in Anti-Aging and Regenerative Medicine through the American Academy of Anti-Aging Medicine. Her special interests include use of PLLA, Ablative/Non ablative skin resurfacing, PDO threads, hormone therapy and nutritional therapies to improve cellular regeneration and medically supervised weight loss.

Jenna Hilton believes in a multi-factorial approach, considering internal factors that accelerate aging and disease development. She always enjoys teaching. She co-founded Vibrant EDU courses at Vibrant Skin Bar and regularly performs one-on-one training with fellow injectors. She teaches Aesthetic and Advanced Injectable Courses at National Laser Institute. She has been named Preceptor of the Year and is an Adjunct Faculty Member at Midwestern University. She was born in Iowa, and lives with her husband and three children in Phoenix, AZ.

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