The Role of Vitamin B-12 in Thyroid Health

by Dr. Edward Group DC, NP, DACBN, DCBCN, DABFM Published on

A woman is walking through a sunny field. Vitamin B-12 is one of the several nutrients that helps support thyroid health.Your personal wellness and the efficiency at which your body operates is a direct result of the quality and completeness of the nutrients you consume. Complete nutrition promotes complete wellness, nutritional deficiencies result in wellness deficiencies. Energy levels and metabolism are some of the most noticeable status indicators of wellness. To encourage both to be at their best, special attention needs to be paid to thyroid gland health and vitamin B-12 intake. A sluggish thyroid, or hypothyroidism, may cause you to be deficient in vitamin B-12, and the resulting vitamin B-12 deficiency can further exacerbate the slow thyroid or negatively affect energy.[1]

Thyroid Gland and Its Function

The thyroid gland is a small, butterfly-shaped gland in the front of your neck. It’s the brain of the endocrine system and responsible for synthesizing thyroid hormones T3 and T4 which control metabolism and heartbeat.[2] The gland secretes more thyroid hormone when you need a boost in energy, such as when you’re cold. The hormone boost cues your body to speed up your metabolism, or the rate at which chemical reactions occur, and this generates more heat and raises your body’s temperature. Consequently, thyroid hormones affect your basal metabolic rate (BMR) and that determines how many calories you burn while you’re at rest.[3]

Functions of Vitamin B-12

Although daily B-12 requirements are fairly low (just 2.4 micrograms for teenagers and adults[4]) it plays a crucial role in metabolic and cellular processes. B-12 is the catalyst for red blood cell production, DNA synthesis, protein conversion, neurological function,[5] fatty acid synthesis,[6] and nerve health.[4]

Symptoms and Effects of B-12 Deficiency

The process of metabolizing vitamin B-12 is a complicated one and there are several ways to develop a deficiency. The vitamin B-12 found naturally in food is bound to proteins. Once consumed and in the stomach, it separates from these proteins through the action of pepsin and gastric acid. From here, it immediately binds to R protein from saliva which protects it from damage in the acidic environment. In the duodenum, the first section of the small intestine, the B-12-R protein complex splits apart. Intrinsic factor (IF), a protein secreted in the stomach, joins B-12 and safely transports it past the protein-digesting enzymes that would otherwise destroy the vitamin. Once it reaches the last part of the small intestine, the ileum, it’s absorbed from the GI tract where B-12 detaches from IF and joins transcobalamin to become B-12–TC-II. This last complex is taken up by the bone marrow, liver, and other cells; the liver stores 90% of a person’s B-12.[1]

A B-12 deficiency may result when you either don’t consume enough B-12, or your body doesn’t absorb enough B-12. Absorption problems can result from inadequate intrinsic factor, digestive enzyme problems, or organ damage. Symptoms of deficiency vary depending on severity. The most common include fatigue, constipation, decreased appetite, tingling in the hands and feet, impaired memory, depression, and soreness of the tongue.[4]

Some people have a higher risk of B-12 deficiency:

  • Older adults, due to decreased hydrochloric acid in the stomach.[4]
  • People whose bodies don’t produce enough intrinsic factor.[4]
  • Vegetarians and vegans who don’t get B-12 from food.[4]
  • People with conditions that irritate mucosal lining in the stomach and intestines, such as Crohn’s or celiac disease,[7] chronic alcoholism, or inflammatory bowel disease.[8]

Effect of Hypothyroidism on B-12 Absorption

Hypothyroidism can compromise your ability to absorb vitamin B-12. An infection of Helicobacter pylori bacteria may also interfere with gastric secretions and hinder B-12 absorption.[9]

Experts believe that 4.6% of the U.S. population age 12 and up suffers from hypothyroidism.[6] One study found that approximately 40% of hyperthyroid patients also suffer from a B-12 deficiency. Adding supplementary B-12 to these patients’ routines improved weakness, memory, mood, and other symptoms.[10] The USDA recommends B-12 supplementation for people at risk of deficiency because it’s more easily absorbed than B-12 from food sources.[11]

Dietary Sources of Vitamin B-12

The most common sources of B-12 are meat, seafood,[12] eggs, and dairy.[13] Since vitamin B-12 is produced by a soil based bacteria,[14] animals pick it up while foraging for food. Some vegetarian sources such as fortified cereals and nutritional yeast do exist if you’re trying to avoid animal products. A B-12 supplement is a great way to fill the gaps in your nutritional intake.

The Benefits of B-12 Supplementation

A B-12 supplement is invaluable, especially for older adults. The right B-12 supplement is easily absorbed and provides the B-12 the human body requires. All people at risk of B-12 deficiency should consider a B-12 supplement.[4] VeganSafe B-12™ offers the most bioactive forms of B-12 — methylcobalamin and adenosylcobalamin.

While B-12 is an essential vitamin for supporting thyroid health, the importance of iodine and selenium cannot be overlooked. That’s why we created the Thyroid Health Kit™; it contains all of our best thyroid support supplements — vitamin B-12, selenium, and iodine.

Have you added a B-12 supplement to your day? What effects have you noticed? Leave a comment below and share your experience with us.

References (14)
  1. Kibirige, Davis, and Raymond Mwebaze. “Vitamin B-12 Deficiency Among Patients with Diabetes Mellitus: Is Routine Screening and Supplementation Justified?” 12. (2013): n.pag. Web. 23 Aug. 2016.
  2. “Thyroid diseases.” NIH. U.S. National Library of Medicine, 18 Aug. 2016. Web. 23 Aug. 2016.
  3. “How does the thyroid work? - PubMed health - national library of medicine - PubMed health.” (2015): n.pag. Web. 23 Aug. 2016.
  4. “Office of dietary supplements - vitamin B-12.” 24 June 2011. Web. 23 Aug. 2016.
  5. “Office of dietary supplements - dietary supplement fact sheet: Vitamin B-12.” NIH. 11 Feb. 2016. Web. 23 Aug. 2016.
  6. “B-12.” Australian Government National Health and Medical Research Council. 1 Jan. 2005. Web. 23 Aug. 2016.
  7. “Hypothyroidism (Underactive Thyroid).” National Institute of Diabetes, Digestive and Kidney Disorders. 18 Aug. 2016. Web. 23 Aug. 2016.
  8. America, Colitis Foundation of. “CCFA: Nutrition and IBD.” Crohn’s & Colitis Foundation of America. 2016. Web. 23 Aug. 2016.
  9. Lahner, Edith, and Bruno Annibale. “Pernicious Anemia: New Insights from a Gastroenterological Point of View.” 15.41 (2009): n.pag. Web. 23 Aug. 2016.
  10. Jabbar, A, et al. “Vitamin B-12 Deficiency Common in Primary Hypothyroidism.” JPMA. The Journal of the Pakistan Medical Association. 58.5 (2008): 258–61. Web. 23 Aug. 2016.
  11. “Questions to ask before taking vitamin and mineral supplements.” 22 Aug. 2016. Web. 23 Aug. 2016.
  12. “Foods highest in vitamin B-12.” SELF Nutrition Data. 2014. Web. 23 Aug. 2016.
  13. Wax, Emily, et al. “Vegetarian diet: MedlinePlus medical encyclopedia.” MedlinePlus. 12 Jan. 2014. Web. 23 Aug. 2016.
  14. Campbell, Thomas, Alan Goldhamer, and Jill Edwards. “12 questions answered regarding vitamin B-12 - nutrition.” Articles. Center for Nutrition Studies, 6 Feb. 2015. Web. 23 Aug. 2016.

†Results may vary. Information and statements made are for education purposes and are not intended to replace the advice of your doctor. Global Healing Center does not dispense medical advice, prescribe, or diagnose illness. The views and nutritional advice expressed by Global Healing Center are not intended to be a substitute for conventional medical service. If you have a severe medical condition or health concern, see your physician.

  • Cecilia Christensen

    I started taking B12 a number of years ago, not because I’m Vegan or vegetarian, but because I’ve had chemotherapy for breast cancer, and radioactive iodine for hyperthyroidism. I started noticing swigglly lines in my vision, and dizzness with exercise. Just these slight annoying disturbances which could not be pinpointed to anything thing else. Also, the tingling in the hands when waking up in the am. I wish that they had better tests for measuring and assessing the bodies ability to utilize this vitamin. I’m taking a under the tongue one right now, low dosage, but it has stevia in it. Yucky aftertaste.

Top Selling Supplements

Colon Cleanser Oxy-Powder® is the top quality colon cleanser. Promotes optimal colon health and regular bowel activity. Learn More

Liver Cleanse Kit This complete liver cleansing kit is a comprehensive approach to cleansing your liver. Learn More

Get to know Dr. Group

  Our Company




  • Global Healing Center
    2040 North Loop West, Ste. 234
    Houston, Texas 77018
    Telephone: 713-476-0016
    Toll Free: 1-800-476-0016
  • Contact Us