Hypothyroidism is one of the most common endocrine disorders worldwide. Hypothyroidism and subclinical hypothyroidism have a prevalence rate of 4–5% and 4–15%, respectively.1,2 The prevalence is around three to seven times higher in women than men, and its incidences proportionally increase with age.3Due to its nonspecific symptoms, hypothyroidism often goes undetected in adults. Some of the most common symptoms of hypothyroidism include fatigue, lethargy, insomnia, and issues with concentration and memory. Current research shows that a few lifestyle factors, such as birth-control pills, may increase the likelihood of the development of hypothyroidism in women. This paper seeks to identify a few lifestyle factors and nutrient deficiencies that may potentially increase the likelihood of the development/progression of hypothyroidism. Also, examples of evidence-based natural solutions that may help you with your thyroid function will further be discussed.

History of Using Oral Contraceptives and Development of Hypothyroidism—Is There a Link?

probioticsHormones present in birth-control pills may affect thyroid function in different ways. Iodine deficiency is a leading cause of hypothyroidism, and ethinyl estradiol and progestin, present in birth-control pills, may influence iodine uptake, potentially contributing to the development of hypothyroidism in susceptible individuals. 4 Estrogen may cause a reduction in thyroxine synthesis by upregulating the activity of the thyroid peroxidase and downregulating the expression of thyrotropin-releasing hormone mRNA in the paraventricular nucleus cells.5 Estrogen may also activate the phosphatidylinositol 3‑kinase (PI3K) pathway in the thyroid follicular cells and increase women’s susceptibility to thyroid disease.6 Research has shown that progesterone may also upregulate the expression of thyroglobulin, thyroperoxidase, and sodium iodide symporter mRNA in vitro;7 all of which may potentially lead to the underfunctioning of your thyroid gland.

A Recent Cross-Sectional Study

In one very recent cross-sectional study using a large epidemiological survey, the association between the use of birth-control pills and thyroid function in women has been studied.8 Participants included a total of 5,116 female adults aged 18 and above whose data on the history of taking birth-control pills and their thyroid functions were identified. For the study, females who had thyroid-stimulating hormone (TSH) between 0.34 mIU/L and 5.6 mIU/L and were not taking any thyroid-hormone replacement or antithyroid medication were identified as euthyroid. Those with TSH > 5.6 mIU/L and not on any antithyroid medication, as well as those on thyroid-hormone replacement regardless of their TSH levels, were classified as hypothyroid. Participants who had never taken birth-control pills showed a higher prevalence of hypothyroidism on the multivariate logistic regression analysis (17.7% v. 14.1%; p = 0.003). Multivariate logistic regression was adjusted for confounding covariables. These confounding variables included age, race, education, body mass index, smoking status, alcohol use, history of thyroid disease, current thyroid disease, first menstrual age, pregnancy history, menopause status, and history of hormone-replacement use. Results revealed a significant association between a history of taking birth-control pills for more than ten years and the prevalence of development of hypothyroidism (OR 3,837; 95% CI: 1,402 to 10,500; p = 0.009). The long history of using birth-control pills was associated with hypothyroidism; this was especially true if the participants had been on birth-control pills for more than ten years.9

In the next section, we will explore a few nutrients and vitamins that may help with the thyroid function.

Zinc Supplementation for Patients with Hypothyroidism

Previous research has shown that zinc (Zn) plays a vital role in the metabolism of thyroid hormones. More specifically, it regulates deiodinases enzyme’s activity, thyrotropin-releasing hormone (TRH), and thyroid-stimulating hormone (TSH) synthesis. It also modulates the structures of essential transcription factors involved in thyroid hormone synthesis. The serum concentration of zinc appears to influence the levels of serum T3, T4, and TSH.10 However, zinc supplementation does not restore a hypothyroid but supports a deficiency alongside the illness.

Results from a recent study performed on a small sample size of 27 patients with hypothyroidism and 27 patients within a control group have revealed that serum zinc, interleukin‑6, and tumour necrosis factor‑α levels were significantly lower in those with hypothyroidism (p < 0.05) compared to the control group. Patients in both groups were not taking any supplements/treatments for their thyroid. In the intervention group, thyroid hormones were measured both at the beginning of the diagnosis time and then again, six months after daily Zn supplementation (elemental zinc, 20 mg/d, once daily). Thyroid hormones were measured only at the study entry within the control group. After zinc administration, the patients within the intervention group showed a significant increase in interleukin‑6 and tumour necrosis factor-α levels (p < 0.05) in comparison with the control group.11

Does Vitamin D Play a Role in Hypothyroidism?

Thyroid glands have vitamin D receptors.12 Recent studies have shown the role of vitamin D deficiency in both non–autoimmune hypothyroidism and autoimmune thyroid conditions, such as Hashimoto’s thyroiditis.13,14,15,16,17 Current research shows that patients with hypothyroidism may suffer from hypovitaminosis D with hypocalcemia (low vitamin D and calcium levels).18,19In one small-sample–sized study, using a spectrophotometric method, serum vitamin D [25(OH)D] levels were measured in 30 healthy patients and 30 patients with hypothyroidism. Vitamin D levels lower than 20 ng/ml were identified as vitamin D deficiency. Thyroid hormones (TSH, T3, and T4) and calcium levels were then measured in all participants. Results revealed that serum 25(OH)D levels were significantly lower in hypothyroid patients than in controls. Vitamin D levels were no different between genders (t = −1.32, p > 0.05). Furthermore, serum calcium levels were significantly decreased in hypothyroid patients when compared to the control group. Levels of calcium and vitamin D were significantly associated with the severity of hypothyroidism.20

Conclusion

There appears to be an association between long-term birth-control–pill use and the onset of hypothyroidism. Moreover, according to some small studies, there seems to be an association with hypothyroidism and low serum zinc, low calcium, and low vitamin D. Further studies are warranted, and knowledge on these factors may help with preventive measures.

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