It seems that vitamin D influences almost everything in the body. The connection of vitamin D to thyroid health has been studied. The most common cause of low thyroid (hypothyroidism) is an autoimmune condition known as autoimmune thyroiditis or Hashimoto’s thyroiditis. Approximately 85% of hypothyroid cases result from the immune system attacking and damaging the thyroid gland over time. As a result, there can be a reduction in thyroid hormone production.
If you have an autoimmune thyroid problem, it would be prudent to optimize your serum vitamin D level. When I check my patients' blood levels, it is always shocking to see how many have vitamin D deficiency or low levels. According to the Linus Pauling Institute, 95% of American adults do not meet the Estimated Average Requirement for vitamin D.
I also recommend that people with any autoimmune disease optimize their vitamin D level. Researchers have demonstrated, in a review of many studies, that vitamin D effectively reduces anti-thyroid antibodies (and the risk of other autoimmune diseases). This is important to preserve thyroid gland function.
Besides sunlight exposure to the skin, the best way to control your vitamin D level is with D3 supplementation. A good goal is a serum level close to mid-range of 50 ng/ml. Food sources of vitamin D are uncommon in the American diet. I always recommend long-term D3 supplementation be done in combination with K2. One of the benefits of vitamin D is that it allows calcium absorption in the intestines. Vitamin K2, which is commonly low in the American diet as it is mainly found in fermented soy foods, directs calcium to the bones.
Dr. Mark Stengler NMD, MS, is a bestselling author in private practice in Encinitas, California, at the Stengler Center for Integrative Medicine. His newsletter, Dr. Stengler’s Health Breakthroughs, is available at www.markstengler.com and his product line at www.drstengler.com
Babić Leko, M., Jureško, I., Rozić, I., Pleić, N., Gunjača, I., & Zemunik, T. (2023). Vitamin D and the thyroid: A critical review of the current evidence. International Journal of Molecular Sciences, 24(4), Article 3586. https://doi.org/10.3390/ijms24043586
Micronutrient inadequacies in the US population: An overview. Linus Pauling Institute. https://lpi.oregonstate.edu/mic/micronutrient-inadequacies/overview
