Reduce Thyroid Antibodies - A Key Vitamin You Need to Know About.


Taking a Vitamin D supplement lowered thyroid antibodies in Hashimoto’s hypothyroidism and this may just help you feel better! (3).

So many people who see me have been told there is absolutely no way to reduce thyroid antibodies and yet there are scientists working on this problem at this very moment and publishing papers like this one to give us all hope and a direction to follow.  

The Vitamin D & Hashimoto’s Story So Far:

We’ve known for some time that low vitamin D status was associated with the most common cause of hypothyroidism in the US, UK and Australia  – an autoimmune disease called Hashimoto’s thyroiditis.   

What we’ve not known was if increasing vitamin D levels would have any impact on Hashimoto’s (1,2)

This Is Brand New Information:

Women with Hashimoto’s hypothyroidism taking the number one medication prescribed for hypothyroidism, levothyroxine (also called Oroxoine, Thyroxine, Synthyroid, Tirosint, Levothyroid), were studied with promising results. When Vitamin D was taken as a supplement their thyroid antibodies reduced (1).

Why Should I Even Care About Antibody Levels?

Have you been told you don’t need to be concerned with your antibody levels because you are on a thyroid hormone replacement?  Yet the larger the number of antibodies the greater the immune attack on your thyroid and the worse you might feel (3,4). 

Don’t think the prescription for thyroid medication is lowering antibodies because that is not what it is doing.  Levothyroxine (that is Oroxoine, Thyroxine, Synthyroid, Tirosint, Levothyroid) is increasing the amount of thyroid hormone in your body but it is doing nothing to calm the antibody attack on your thyroid gland.

People with high Hashimoto’s antibody levels have been found to experience:

-      Chronic fatigue (3)

-      Dry hair (3)

-      Chronic irritability (3)

-      Chronic nervousness (3)

-      A history of breast cancer (3)

-      Early miscarriage (3)

-      Lower quality-of- life levels (3)

-      Worse mental health (4).

Do we shout this from the roof tops?

The study was only on 34 women which is not a big number. It does though build happily on the picture started research on 218 Hashimoto’s hypothyroid sufferers given a Vitamin D supplement (2). 

Pop a Pill or Sit in the Sun?

Vitamin D is made in our body after being exposed to sunshine so I would love to issue a prescription for time in the sun* for Hashimoto’s hypothyroidism for you!  Except a study done in sunny Crete in Greece on 218 Hashimoto’s hypothyroidism sufferers found when they were given a Vitamin D supplement they ended up with lower levels of antibodies attacking their thyroid (2).

This means we simply do not know if more time in the sun will have any impact at all.  For predictable results in reducing thyroid antibodies via Vitamin D this study suggests taking a supplement.

The Bottom Line:

It still is early days to make a definitive recommendation so when that happens I like to do a pro’s and cons comparison.


•          Keeping your Vitamin D in the optimal range may just mean lower thyroid antibodies, less immune attack on your thyroid, and a better quality of life.

•          Good quality Vitamin D3 supplements (with Vitamin K2) could be cheap insurance for your health and wellbeing.

•          Healthy Vitamin D levels are correlated with better health outcomes in general.


•          It is still early days in the Vitamin D story for Hashimoto’s hypothyroidism.  When larger, better quality studies are done it may be found that Vitamin D supplements do in fact not reduce thyroid antibodies significantly.  Which means the money spent on Vitamin D supplements may have not helped you achieve your health goal of reduced thyroid antibodies.

I’m inside right now but I’m going get outside, arms and legs bared for a spot of sunshine today!

In Health

Sonia x

Research Study Details (1):

People studied: 34 women with Hashimoto’s thyroiditis and normal vitamin D status (serum 25-hydroxyvitamin D levels above 30 ng/mL) who had been treated for at least 6 months with levothyroxine.

Method used: 2 groups, receiving (n=18) or not receiving (n=16) oral vitamin D preparations (2000 IU daily).

Testing: Serum levels of thyrotropin (thyroid stimulating hormone), free thyroxine (T4), free triiodothyronine (T3) and 25-hydroxyvitamin D (Vitamin D), as well as titers of thyroid peroxidase (antiTPO antibodies) and thyroglobulin (Tg antibodies) antibodies were measured at the beginning of the study and 6 months later.

Results: Low Vitamin D levels were found to be linked to higher thyroid antibody levels, that is, an increased attack on the thyroid. Higher Vitamin D levels were found to be linked to lower thyroid antibody levels most especially the anti-TPO antibodies.

Research Study Details (2):

People studied: 218 Hashimoto’s thyroiditis (HT) patients whose thyroid function was within normal levels: 180 females and 38 males aged 35.3 ± 8.5 years.

Methods used: The 186 vitamin D deficient HT patients received vitamin D3 orally, 1200-4000 IU, every day for 4 months aiming to maintain serum 25(OH)D levels ≥ 40 ng/mL.

Testing: Anthropometric characteristics (height, weight, waist circumference), systolic and diastolic blood pressure, serum concentration of 25(OH)D, thyrotropin (TSH), free thyroxine (FT4), anti-thyroid peroxidase (anti-TPO), antithyroglobulin (anti-TG), calcium and phosphorus levels and thyroid and kidney sonographic findings were recorded and measured before and after supplementation. 

Results: After 4 months of supplementation a significant decrease (20.3%) of thyroid antibodies (specifically anti-TPO antibodies) was found suggesting supplementation with Vitamin D3 couldbe a valuable treatment option for those with Hashimoto’s thyroiditis. 

*Obviously protect yourself from sun cancer by never letting yourself burn, and while we are talking common sense, there is little benefit in exposing your face.  Rather take your long sleeve shirt off, roll up your pants and get sun on your arms and legs.

If you have been given medical advice to avoid the sun you must follow that advice as a priority.

Never look directly at the sun.  


1. Krysiak, R., Szkróbka, W., & Okopień, B. (2017). The Effect of Vitamin D on Thyroid Autoimmunity in Levothyroxine-Treated Women with Hashimoto’s Thyroiditis and Normal Vitamin D Status. Experimental and Clinical Endocrinology & Diabetes, 125(04), 229-233. doi: 10.1055/s-0042-123038

2. Mazokopakis, E. E., Papadomanolaki, M. G., Tsekouras, K. C., Evangelopoulos, A. D., Kotsiris, D. A., & Tzortzinis, A. A. (2015). Is vitamin D related to pathogenesis and treatment of Hashimoto’s thyroiditis. Hellenic Journal of Nuclear Medicine, 18(3), 222-227.

3. Ott, J., Promberger, R., Kober, F., Neuhold, N., Tea, M., Huber, J. C., & Hermann, M. (2011). Hashimoto's thyroiditis affects symptom load and quality of life unrelated to hypothyroidism: a prospective case–control study in women undergoing thyroidectomy for benign goiter. Thyroid, 21(2), 161-167. 

4. Watt, T., Hegedüs, L., Bjorner, J. B., Groenvold, M., Bonnema, S. J., Rasmussen, Å. K., & Feldt-Rasmussen, U. (2012). Is thyroid autoimmunity per se a determinant of quality of life in patients with autoimmune hypothyroidism?. European Thyroid Journal, 1(3), 186-192. doi:  10.1159/000342623

Sonia McNaughton