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Thyroid FunctionEvidence & Dosage

Thyroid function for metabolism, energy, and mental clarity.

Studies last updated

Evidence at a glance

Total studies
578
With abstract
50
Meta / Systematic / RCT
72
Highly cited
36
Publication years
1978–2026

Thyroid Function in the context of Hormones

This topic is part of our "Hormones" world. There you'll find methodology, evidence and the highest-impact levers — plus the order in which they sensibly build on each other.

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Top studies on Thyroid Function

Ranked by influential-citation count and publication year.

  1. Relationship between Iron Deficiency and Thyroid Function: A Systematic Review and Meta-Analysis.

    Nutrients2023n=4,395Meta-Analysis76 influential citations

    Objective: Iron deficiency (ID) is the most prevalent nutritional deficiency worldwide. Low levels of serum ferritin (SF) could affect the thyroid gland and its functioning. The purpose of this systematic review and meta-analysis is to…

  2. Does fluoride exposure affect thyroid function? A systematic review and dose-response meta-analysis.

    Environ Res2024Meta-Analysis71 influential citations

    <h4>Introduction</h4>Fluoride exposure may have various adverse health effects, including affecting thyroid function and disease risk, but the pattern of such relation is still uncertain.<h4>Methods</h4>We systematically searched human…

  3. The optimal healthy ranges of thyroid function defined by the risk of cardiovascular disease and mortality: systematic review and individual participant data meta-analysis.

    Lancet Diabetes Endocrinol2023n=134,346Meta-Analysis69 influential citations

    <h4>Background</h4>Reference intervals of thyroid-stimulating hormone (TSH) and free thyroxine (FT<sub>4</sub>) are statistically defined by the 2·5-97·5th percentiles, without accounting for potential risk of clinical outcomes. We aimed…

  4. The Influence of Nutritional Intervention in the Treatment of Hashimoto's Thyroiditis-A Systematic Review.

    Nutrients2023n=2Systematic Review49 influential citations

    Diet can be a complementary treatment for Hashimoto’s disease by affecting thyroid function and anti-inflammatory properties. It is still unclear which dietary strategy would be the most beneficial. The aim of this systematic review is to…

  5. Association between ambient air pollution and thyroid hormones levels: A systematic review and meta-analysis.

    Sci Total Environ2023n=357,226Meta-Analysis49 influential citations

    <h4>Background</h4>Growing studies have focused on the effects of ambient air pollution on thyroid hormones (THs), but the results were controversial. Therefore, a systematic review and meta-analysis was conducted by pooling current…

    Finding: PM2.5 exposure was significantly associated with hypothyroxinemia and high thyroid-stimulating hormone (TSH).

  6. Association of Gestational Free and Total Triiodothyronine With Gestational Hypertension, Preeclampsia, Preterm Birth, and Birth Weight: An Individual Participant Data Meta-analysis.

    J Clin Endocrinol Metab2024n=33,118Meta-Analysis40 influential citations

    <h4>Context</h4>Triiodothyronine (T3) is the bioactive form of thyroid hormone. In contrast to thyroid-stimulating hormone and free thyroxine, we lack knowledge on the association of gestational T3 with adverse obstetric…

  7. Effect of gluten-free diet on autoimmune thyroiditis progression in patients with no symptoms or histology of celiac disease: a meta-analysis.

    Front Endocrinol (Lausanne)2023n=87meta38 influential citations

    BACKGROUND: Hashimoto's thyroiditis (HT) is the most common autoimmune disease. HT may be associated with nonthyroidal autoimmune diseases, including celiac disease (CD) or other gluten-related conditions (GRC). In the last years, interest…

  8. Thyroid function during COVID-19 and post-COVID complications in adults: a systematic review.

    Front Endocrinol (Lausanne)2024n=53Systematic Review37 influential citations

    The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, has presented multifaceted health challenges. COVID-19 primarily targets the respiratory system but also…

  9. Perchlorate and thiocyanate exposure and thyroid function in first-trimester pregnant women.

    J Clin Endocrinol Metab2010n=164Study36 influential citations

    CONTEXT: Thyroid hormone, requiring adequate maternal iodine intake, is critical for fetal neurodevelopment. Perchlorate decreases thyroidal iodine uptake by competitively inhibiting the sodium/iodide symporter. It is unclear whether…

  10. Prevalence of subclinical hypothyroidism in polycystic ovary syndrome and its impact on insulin resistance: a systematic review and meta-analysis.

    BMC Endocr Disord2025n=576Meta-Analysis36 influential citations

    <h4>Background</h4>Although recent studies indicate a high prevalence of subclinical hypothyroidism (SCH) in women with polycystic ovary syndrome (PCOS), the reported prevalence rates vary widely. Therefore, we conducted this study to…

Frequently asked

What dosage was studied?
• Iron deficiency exposure / low serum ferritin • Fluoride exposure (Highest vs lowest fluoride category; dose-response analysis of water fluoride exposure around 2.5 mg/L threshold) • Assessment of thyroid function (TSH and FT4) (Not applicable)
Which population does the evidence apply to?
Most studies investigated: unknown.
Are there safety considerations for Thyroid Function?
• No intervention was tested; no adverse events were reported. • Prospective RCTs are suggested by the authors to clarify iron safety/benefit in thyroid health. • High-fluoride drinking water was associated with increased TSH release above about 2.5 mg/L. • The review suggested increased risk of goiter and hypothyroidism with fluoride exposure.

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