Written on August 28, 2023 by Sendra Yang, PharmD, MBA. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
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Vitamins are essential for your body to function correctly. The known vitamins are A, C, D, E, K, and B. There are eight B vitamins, one of which is vitamin B12. Vitamin B12, also known as cobalamin, is vital for various pathways in the body.[2,3] It is a water-soluble vitamin, meaning it cannot be stored in your fat tissues, and you need to consume this vitamin throughout your diet.
With the increasing obesity prevalence (up to around 42%) in the United States and many people trying to lose weight every year, B12 has been suggested as a possible remedy for weight loss.[4-6] Continue reading to learn more about whether B12 can help with weight loss.
Vitamin B12 has a role in proper red blood cell formation, cell metabolism, nerve function, and DNA production.[3,7] DNA is the genetic material located inside body cells. Vitamin B12 is needed for two significant enzymes central to biological pathways, including DNA and protein synthesis. Vitamin B12 also impacts the process of fat metabolism.
Vitamin B12 is absorbed through the intestines and can be stored in the liver for up to a year. B12 is available in foods like red meats, fish, poultry, eggs, milk, and dairy products. The vitamin can also be fortified in foods such as nutritional yeast, certain bread, and breakfast cereals. Fortified foods are foods with added vitamins and nutrients that do not naturally have them.
Human trials have demonstrated the association of vitamin B12 with obesity.[9-11] A study including 9,075 adult participants in the National Health and Nutrition Examination Survey evaluated the association of serum vitamin B12 concentrations with obesity in the United States. The serum vitamin B12 concentrations were found to be lower in obese adults compared with non-obese adults. Individuals with higher serum vitamin B12 levels were less likely to be obese. However, some studies investigating the association between vitamin B12 concentrations and obesity were inconsistent.[12, 13]
Vitamin B12 has various functions in the different body pathways.[3,7,8] Although some studies have reported an association between low vitamin B12 levels and obesity, the results were inconsistent.[9-13] So, does vitamin B12 help with weight loss? It is not clear if vitamin B12 can lead to losing weight. Vitamin B12 has been suggested to help increase energy levels in people with low levels. But if you already have normal vitamin B12 serum levels, supplementing with vitamin B12 will not likely improve your energy.[6,7]
Vitamin B12 deficiency occurs when you do not have enough or are not absorbing enough vitamin B12 for your body. Not getting adequate amounts of vitamin B12 can cause physical, nerve, and mental issues. Conditions that can lead to vitamin B12 deficiency include :
Symptoms of vitamin B12 deficiency can develop slowly and worsen over time, though some people have no symptoms. General physical symptoms are fatigue, nausea, vomiting, diarrhea, sore mouth or tongue, yellowish skin, diminished appetite, and weight loss. Nerve-related symptoms may not be reversible and include vision issues, numbness or tingling in your hands and feet, memory loss, confusion, and difficulty walking or speaking.
If you are trying to lose weight and would like to discuss it with a healthcare provider, Everlywell has a Weight Care+ program that pairs GLP-1 prescriptions online with regular clinical care, lab testing, and support for related conditions. You have access to regular one-on-one virtual visits with a licensed healthcare provider to discuss your weight goals with lifestyle support and recommendations.
During the initial session, your healthcare provider will review and evaluate your medical history and order any appropriate lab testing that may be needed to determine whether weight loss medication may be for you. At your second visit, your provider will evaluate your test results and discuss your health and weight-related goals to help design a personalized care plan. If you start a medication, you will have regular check-ins with your certified clinician. They will review your weight loss progress, assess your medication tolerance, order follow-up lab testing or prescription refills, and adjust your care plan as necessary.