Are you doing everything right for your Hashimoto’s disease and hypothyroidism but still experiencing fatigue? A chain is only as strong as it’s weakest link and the b-vitamin thiamine is an important link in thyroid function and energy production that could improve Hashimoto's disease-related fatigue. Restrictive diets like the Autoimmune Paleo Diet, gluten-free diet, and ketogenic diet can possibly lead to a thiamine deficiency if there isn’t enough variety in the diet. Once this important vitamin becomes deficient, a number symptoms can appear as well as sluggish thyroid function.

An interesting study was published in the Journal of Alternative and Complementary Medicine entitled “Thiamine and Hashimoto’s Thyroiditis: A Report of Three Cases” which looked at thiamine deficiency and Hashimoto’s disease. The authors begin by stating that levothyroxine is the treatment of choice for hypothyroidism however some patients still complain of fatigue after taking this medication and their lab tests look normal.

How was this study done on thiamine and Hashimoto's disease-related fatigue?

The sample size was quite small at only 3 women with a diagnosis of Hashimoto’s disease and hypothyroidism. All of them were taking the prescription thyroid hormone levothyroxine. These women reported the following symptoms: fatigue, sleep disorders, depression, anxiety, chronic nervousness, memory loss, focus and attention disorders, cold intolerance, and dry skin.

The participants filled out the Fatigue Severity Scale which is a subjective questionnaire that assesses the severity of fatigue. They filled this out at the beginning of treatment and 20 days after beginning treatment.

TSH, Free T4, and Free T3 were tested all of which came back normal. TPO antibodies were also measured and these came back elevated in all three subjects. Additionally, thiamine levels were tested to identify deficiency but none of the patients were deficient in thiamine.

Two of the patients took 600mg/day of thiamine orally and one patient received 100mg injections of thiamine every 4 days. This was done for 20 days and then the patients reported their results.

What were the results of this study?

All three patients reported improvement in their fatigue levels. Patients 1 and 2 reported 100% elimination of their fatigue and patient 3 reported moderate improvement. Looking more closely at the numbers, patient 3 had the highest levels of TPO antibodies at 1,725 compared to patient 1 at 322 and patient 2 at 526. Patient 3 may not have gotten the same improvement as the other two patients due to her antibodies being so high. Elevated antibodies do correlate with symptom severity in Hashimoto’s disease so this is a possible explanation.

The authors do state that ongoing intake of thiamine should be accompanied by all of the B-vitamins in a B-complex form. This is because all of the B-vitamins work together and taking high doses of one without the other could cause problems over time.

Author discussion

Why would we see improvement in fatigue if none of the patients were deficient in thiamine to begin with? The authors explain that there could be issues with th...