Thiamine - Vitamin B1 - Fatigue, and Autoimmune Thyroid Disease

tired exhausted fatigued thyroid
Thiamine - vitamin B1 - may help fatigue in thyroid patients.

The main function of thiamine (vitamin B1) -- note, thiamine is also frequently spelled thiamin -- is to help change carbohydrates into energy, with a focus on providing energy to your brain and nervous system.

Acccording to MedLine, thiamine is found in the following foods:

  • Enriched, fortified, and whole grain products such as bread, cereals, rice, pasta, and flour
  • Beef liver and pork
  • Dried milk
  • Eggs
  • Legumes and peas
  • Nuts and seed

Insufficient levels of thiamine are known to cause fatigue and weakness, and in more severe cases, even psychosis and nerve damage. Factors that can contribute to thiamine deficiency include poor dietary intake, digestive absorption problems, and metabolic imbalances. A severe lack of thiamine is the rare disease known as beriberi. Thiamine deficiency is also more common in people who abuse alcohol, in those who are diabetic, in people with anorexia and other eating disorders, and in those who have had weight loss surgery.

We depend on our daily diet for thiamine, and since thiamine is not stored in the body, a consistant dietary intake of thiamine is necessary to maintain sufficient levels. Experts feel, however, that the majority of Americans do get sufficient thiamine from their food intake.'s Nutrition Expert, Shereen Jegtvig outlines the recommended daily allowances (RDA) for thiamine in adults, which range from 1.0 to 1.1 mg/day.

Thiamine and Autoimmune Disease

Researchers have theorized that some people, and in particular, those with autoimmune diseases, may have a dysfunction or enzymatic imbalance that negatively affects the body's ability to process thiamine at the cellular level. Based on a past study that found that thiamine improved fatigue in inflammatory bowel disease (IBD) patients, researchers decided to evaluate whether the chronic fatigue seen in inflammatory and autoimmune diseases may be evidence of a thiamine deficiency.

The researchers conducted a small study of three patients who were on thyroid hormone replacement treatment for Hashimoto's thyroiditis, and who also suffered from fatigue.

The study took place from May to July 2011. The fatigue was measured during the Fatigue Severity Scale. The patients all had free thiamine blood tests measured before and after the thiamine therapy -- which was either 600 mg/day of thiamine orally, or 100 mg/ml every four days by IV.

The researchers found that the patients had partial or complete regression of fatigue within a few hours or days of the start of the treatment. They concluded that giving large quantities of thiamine restores "thiamine-dependent processes," and relieves fatigue.

For Thyroid Patients: This was a small study, and for it to be widely accepted as scientific proof, a larger, double-blind type study will likely be needed. But meanwhile, if you're a thyroid patient experiencing fatigue, you may want to talk to your doctor about trying higher-dose thiamine.

It's useful to note that thiamine is considered safe, even at higher doses, and there are no reports of toxicity of dietary thiamine or thiamine supplementation.

Thiamine is water soluble, and excess thiamine is excreted in the urine. Given the lack of evidence of toxicity, even the National Academy of Sciences has decided not to establish a Tolerable Upper Intake Level (UL) for thiamine.


Costantini, A, et. al. "Thiamine and Hashimoto's Thyroiditis: A Report of Three Cases." J Altern Complement Med. March 2014. Abstract.
Linus Pauling Institute, Web page

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