Can Vitamin B12 Improve Your Energy Level and Mood?

By: Rachel Novik, DO • Posted on October 11, 2023

What is vitamin B12?

Vitamin B12, also known as cobalamin, is a water-soluble vitamin that plays a role in red blood cell formation, nerve function, and DNA synthesis. It is an essential B vitamin, meaning the body doesn't make vitamin B12, and you have to get it from your diet.

Most people are able to obtain adequate amounts of B12 through their diet. Common food sources of B12 include meat, fish, eggs, and dairy. Additionally, fortified breakfast cereals and nutritional yeast can be a good source of B12.

Who is at risk for vitamin B12 deficiency?

People who are vegan are often deficient in vitamin B12. Additionally, medical conditions affecting stomach and nutrient absorption such as Chron's and UC, gastric bypass, colon surgery are more likely to have deficiency. Similarly, people who are on medications that affect GI transit and absorption such as Proton Pump Inhibitors, colchicine (a medication prescribed for gout), and the diabetes medication, Metformin, can be at higher risk for B12 deficiency.

Low B12 levels can be related to the following symptoms:

Fatigue
Dizziness
Paresthesia (numbness and tingling)
Muscle weakness
Anemia
Mood concerns
Mood changes

How much vitamin B12 is recommended?

The recommended daily amount of vitamin B12 for both women and men is 2.4 mcg. If you are low in B12, your doctor may recommend oral or injectable supplementation. Vitamin B12 supplements are considered safe - your body absorbs what it needs and any excess is excreted in your urine.

Vitamins to take for B12 deficiency

You can supplement B12 through B Complex vitamins as well as a vitamin containing only B12. There are other forms of B12 such as adenosylcobalamin, methylcobalamin, and hydroxycobalamin. If you are unable to swallow a pill, there is a sublingual formulation (dissolves under the tongue) available as well as a nasal gel.

Populations at higher risk of B12 deficiency

Vegetarians and Vegans
Alcoholics
People with digestive diseases
People with Pernicious Anemia
People with a history of stomach or colon surgery
People with Transcobalamin II deficiency
People with gastritis or on medications for stomach acid

Common Symptoms of B12 Deficiency

Fatigue and weakness
Nausea, vomiting, diarrhea
Poor appetite
Weight loss
Oral sores
Numbness or tingling in hands and feet
Vision problems
Poor memory, confusion
Balance and gait instability
Depression
Irritability

What are the health benefits of vitamin B12?

Vitamin B12 reduces circulating blood levels of homocysteine, an amino acid in the body that has been linked to increased heart attack and stroke risk.

Some studies have linked elevated B12 with high risk of certain cancers, however more data is needed at this time.

B12 supplements are often advertised for boosting energy, athletic performance, and endurance. However, if you get enough through your diet, these are unlikely to have added benefit.

Medications that effect B12 absorption

Gastric acid inhibitors: omeprazole (Prilosec®), lansoprazole (Prevacid®), cimetidine (Tagamet®), and ranitidine (Zantac®)
Colchicine
Metformin

Foods with vitamin B12

Beef
Clams (without shells)
Nutritional yeast, fortified
Salmon
Canned Tuna
Milk
Yogurt
Fortified Breakfast cereals
Cheese
Eggs
Turkey
Tempeh
Seaweed

If you have symptoms of vitamin B12 deficiency, see your healthcare provider. Your healthcare provider might order a vitamin B12 test that measures how much vitamin B12 is in your blood.

High levels of vitamin B12

Why is my vitamin B12 level high?

The most common cause of high B12 in the blood is due to recent ingestion or injection of supplemental vitamin B12. Normally, this is no concern about overdosing on B12 supplements because excess can be excreted in your urine.

A high vitamin B12 level could be from a diet high in animal products such as meat, eggs and shellfish. However, it is extremely rare to have a high blood level from too much vitamin B12 in the diet.

There are cases where an individual has an elevated vitamin B12 level that is seen as an incidental finding in someone who has not recently received a vitamin B12 injection or taken a vitamin B12 supplement. Limited observational studies have reported associations of increased vitamin B12 levels with other conditions and disease states, including:

Liver disease due to release of B12 from damaged liver cells into the bloodstream
Kidney disease due to impaired function of the kidneys to excrete excess B12
Increased levels of transcobalamin, which is a transporter of B12 in the bloodstream
Inflammatory conditions: rheumatoid arthritis, lupus
Hematologic (or blood) cancers: acute leukemia, multiple myeloma
Hematopoietic disorder: myeloproliferative neoplasm, myelodysplastic syndrome, hypereosinophilic syndrome, transient neutrophilia

Most of these medical conditions are often present with other abnormal lab findings such as impaired kidney function, liver function, anemia, low white blood cell count and also other signs and symptoms of problems.

What to do if your vitamin B12 level is high?

If vitamin B12 levels continue to be high, you should see a hematologist for a follow up evaluation to receive further review of your history, family history and further laboratory testing if appropriate.

Avoid supplements high in B12 for now, eat a varied healthy diet rich in fruits and vegetables and check to see if B12 is in any supplements you take.

Be Strong, Be Healthy, Be in Charge!

-Rachel Novik, DO

About Rachel Novik, DO

Dr. Rachel Novik is a Board Certified Family Medicine physician. She is a first year clinical Specialized Women’s Health Fellow at the Cleveland Clinic Center for Specialized Women’s Health.

Dr. Novik graduated from New York University with a Bachelor’s Degree in Social Work and a minor in Child and Adolescent Mental Health. She then completed a post-baccalaureate degree for pre-medical sciences at John Carroll University and ultimately attended Ohio University’s Heritage College of Osteopathic Medicine, at their Cleveland campus.

Dr. Novik graduated from University Hospitals St. John Medical Center’s Family Medicine Residency program, where she served as chief resident and helped create a women’s health curriculum. She has a passion for working with women at all stages of their lives. During residency, she developed a desire to focus her practice on women in their middle and later decades, where care gaps often exist.

References

Office of Dietary Supplements - Vitamin B12. (n.d.-b)
Office of Dietary Supplements - Vitamin B12. (n.d.)
Arendt JFH, Sørensen HT, Horsfall LJ, Petersen I. Elevated Vitamin B12 Levels and Cancer Risk in UK Primary Care: A THIN Database Cohort Study. Cancer Epidemiol Biomarkers Prev. 2019 Apr;28(4):814-821. doi: 10.1158/1055-9965.EPI-17-1136. Epub 2019 Jan 14. PMID: 30642843
Brasky TM, White E, Chen CL. Long-Term, Supplemental, One-Carbon Metabolism-Related Vitamin B Use in Relation to Lung Cancer Risk in the Vitamins and Lifestyle (VITAL) Cohort. J Clin Oncol. 2017 Oct 20;35(30):3440-3448. doi: 10.1200/JCO.2017.72.7735. Epub 2017 Aug 22. PMID: 28829668; PMCID: PMC5648175
Ulrich CM, Potter JD. Folate supplementation: too much of a good thing? Cancer Epidemiol Biomarkers Prev. 2006 Feb;15(2):189-93. doi: 10.1158/1055-9965.EPI-152CO. PMID: 16492904
Gilfix BM. Vitamin B12 and homocysteine. CMAJ. 2005 Nov 22;173(11):1360. doi: 10.1503/cmaj.1050170. PMID: 16301715; PMCID: PMC1283514

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