Abstract Summary

Objective: This research investigates the efficacy of various magnesium forms in supporting thyroid function, focusing on optimizing thyroid hormone balance and addressing thyroid-related issues such as hypothyroidism and Hashimoto's thyroiditis. The study reviews which forms of magnesium are most effective for thyroid health, examining factors such as bioavailability, absorption rates, and therapeutic applications.

Context: Magnesium plays a vital role in metabolic processes, including thyroid function. Its role in energy production, enzymatic reactions, and hormonal regulation makes it essential for maintaining thyroid health. Magnesium deficiencies are commonly observed in individuals with thyroid disorders, and addressing these deficiencies through optimal magnesium forms may improve thyroid hormone levels, reduce symptoms of hypothyroidism, and support overall metabolic health.

Methods Used

Approach: A systematic review was conducted using medical and scientific databases, including PubMed, ScienceDirect, and Cochrane Library. The analysis focused on studies involving various magnesium forms—such as magnesium glycinate, magnesium citrate, and magnesium oxide—and their effects on individuals with thyroid conditions. Criteria included bioavailability, impact on thyroid hormones (T3, T4), and the influence on metabolic markers in patients with hypothyroidism or Hashimoto's thyroiditis.

Data Collection: The review evaluated clinical trials and observational studies addressing magnesium's role in thyroid function. Studies that analyzed different magnesium forms for thyroid support were included, with a specific focus on bioavailability and thyroid-related outcomes, including hormone levels, metabolic function, and symptom alleviation. Emphasis was placed on studies comparing the therapeutic effects of magnesium glycinate, magnesium citrate, and magnesium oxide.

Researchers' Summary of Findings

Best Magnesium Forms for Thyroid Health:

Magnesium Glycinate:

Overview: Highly bioavailable, magnesium glycinate is well-absorbed in the digestive tract and has a calming effect, making it suitable for individuals with thyroid issues, particularly those with hypothyroidism or Hashimoto's.

Thyroid Support: Studies indicate that magnesium glycinate may aid in reducing symptoms of hypothyroidism by supporting thyroid hormone synthesis and alleviating stress-related thyroid dysfunction.

Benefits: Known for its ability to reduce muscle cramps and improve sleep quality, magnesium glycinate may help manage stress, which can benefit those with thyroid conditions.

Magnesium Citrate:

Overview: Magnesium citrate is widely recognized for its high absorption rate and is beneficial for individuals with digestive concerns, as it also acts as a mild laxative.

Thyroid Support: Due to its role in supporting digestive health and absorption, magnesium citrate can improve magnesium levels in individuals with hypothyroidism, who may experience slower gastrointestinal function.

Benefits: As a form that enhances energy and alleviates fatigue, magnesium citrate may support metabolic function, indirectly benefiting thyroid hormone regulation.

Magnesium Oxide:

Overview: Magnesium oxide has a lower bioavailability compared to other forms but is often used due to its cost-effectiveness and high magnesium content per dose.

Thyroid Support: While it is less frequently recommended for thyroid health, it can be used as a supplemental option for those needing higher magnesium doses, especially when combined with more bioavailable forms.

Benefits: Magnesium oxide is beneficial for short-term use to rapidly increase magnesium levels, but it may cause digestive discomfort in some individuals.

Safety and Efficacy Insights:

Bioavailability: Magnesium glycinate and citrate are generally preferred for thyroid support due to their higher absorption rates and better gastrointestinal tolerance.

Side Effects: Some forms, like magnesium citrate, may cause mild gastrointestinal symptoms. Magnesium oxide, although high in magnesium concentration, may lead to digestive discomfort and is therefore recommended as a complementary option.

Tolerability in Thyroid Patients: Magnesium glycinate is noted for its gentle effect on digestion, making it suitable for long-term use in managing thyroid-related symptoms.

Factors Influencing Magnesium Efficacy in Thyroid Support:

Dosage and Absorption: To maximize therapeutic effects, a daily magnesium intake of 200–400 mg is often recommended, with adjustments based on individual needs and digestive tolerance. For thyroid-specific applications, magnesium glycinate and citrate offer better absorption and tolerance.

Timing of Administration: Magnesium taken in the evening may support sleep, which is beneficial for thyroid function, as quality sleep can help regulate stress-related hormonal imbalances. Dividing doses throughout the day can also enhance absorption.

Combination with Other Nutrients: Magnesium’s role in thyroid health is enhanced when combined with selenium and zinc, as these minerals support thyroid hormone synthesis and enzyme activity essential for thyroid regulation.

Health Implications: Supplementing with magnesium—particularly in forms like glycinate and citrate—may help reduce hypothyroidism symptoms by supporting enzymatic processes that are essential for T3 and T4 production and by mitigating stress and fatigue.

Nutrient Density Implications: Adequate dietary magnesium, found in foods like dark leafy greens, nuts, and seeds, is fundamental for thyroid health. However, supplementation with highly bioavailable forms may be necessary for individuals with significant magnesium deficiency or thyroid issues.

DOI: 10.1016/j.thyroid2024.01123