A recent study published in Clinical Chemistry and Laboratory Medicine has found that vitamin D deficiency in children is associated with higher amount of thyroid antibodies and changes in thyroid hormones.
The findings build on previous research that shows that vitamin D deficiency is associated with autoimmune thyroid disease and low levels of thyroid-stimulating hormone (TSH), a hormone that tells the thyroid to produce more hormones.
The thyroid is responsible for the development of the brain and nervous system, affects growth, and regulates bone health. In autoimmune thyroid disease, the body mistakenly perceives the thyroid and the hormones it produces as threats, and thus produces antibodies to fight thyroid cells. This causes changes in thyroid hormone levels, which makes it hard for the body to function properly.
In the present study, researchers looked back at chart reviews of one hundred and fifty-three children (57 boys and 96 girls) in Buenos Aires, Argentina, aged between 1-18 years. This study was cross-sectional by design. The researchers looked at the results of lab tests from these patients and looked to see if there was a correlation between the patients’ vitamin D levels and different thyroid hormones and anti-thyroid antibodies.
They looked at two anti-thyroid antibodies specifically, which let the researchers know if the patient’s immune system is attacking their own thyroid tissue and potentially harming it. They also looked at four other thyroid hormones to determine the patients’ thyroid functioning.
This is what they found:
- Thyroid antibodies were significantly higher in vitamin D deficient patients (levels less than 20 ng/ml) than in the vitamin D sufficient patients (levels above 30 ng/ml).
- There was a significant positive correlation between levels of vitamin D in all patients and the thyroid hormones T3, T4, and fT4, meaning that the higher the vitamin D level, the higher levels of these hormones.
- There was a significant negative correlation between vitamin D levels and TSH, meaning the higher the vitamin D level, the lower the TSH. High TSH means that the thyroid is not functioning properly, so lower (but not too low) TSH means a healthier thyroid.
Despite the study’s observational design, the researchers concluded,
“Vitamin D deficiency is responsible for altered autoimmunity with a high prevalence of thyroid auto antibodies in these patients leading to an alteration of thyroid function.”
Their confidence in this cause-effect relationship is based on a large amount of evidence for vitamin D’s role in modulating the immune system. They did temper their findings with the reminder that there isn’t enough evidence that vitamin D supplementation could change the course of the autoimmune diseases (halt or reverse it) and that randomized controlled trials are necessary to figure that out.
Zaidman, V. E., Maceiras, M., Lazzati, J. M., Kutasz, E. P., D’Isa, G., Chilleli, C., Chaler, E. A. (2014). High prevalence of anti-thyroid antibodies associated with a low vitamin D status in a pediatric cohort. Clinical Chemistry and Laboratory Medicine, 1 – 4.