Science Update

Study Explores Supplementation Effect of Vitamin A and Minerals on Hypothyroidism

The thyroid is a gland responsible for certain hormones that are critical to many functions within the human body. Hypothyroidism is a condition related to reduced function of the thyroid gland. Certain nutrients have been linked to thyroid function and hypothyroidism.

Zinc is a mineral that plays a critical role in thyroid hormone regulation. It is a cofactor for certain deiodinases, which are enzymes that help convert thyroxine (T4) into the active form of the thyroid hormone. Zinc also helps facilitate the binding of triiodothyronine (T3) to its nuclear receptor and helps to convert precursor molecules into the thyrotropin-releasing hormone.

In a recent randomized, double-blind, placebo-controlled trial, a higher incidence of hypothyroidism was shown to occur in the presence of a diet low in both vitamin A and iodine when compared to a diet low in iodine alone. Oxidative stress has been associated with the pathogenesis of autoimmune thyroiditis. Vitamin A has been shown to support the body’s response to oxidative stress and may also influence the pituitary-thyroid axis.

Magnesium is the fourth most abundant mineral in the human body, which is critical for many enzymatic reactions. Magnesium is a cofactor in the mediation of thyrotropin in thyroid gland activity. The balance between magnesium and zinc may be associated with changes in thyroid hormone levels.

Researchers assessed the efficacy of the combined supplementation of magnesium, zinc, and vitamin A on individuals with hypothyroidism. The 10-week trial included data from 86 individuals, ranging from 20 to 65 years of age. The treatment arm consisted of a daily supplementation of 30 mg of zinc gluconate and 250 mg of magnesium oxide, along with 25,000 IU of vitamin A twice per week.

The study assessed biomarkers associated with inflammation, oxidative stress, and thyroid function. Study results indicated that the treatment arm experienced a significant decrease in serum high-sensitivity C-reactive protein levels. Significant differences in total antioxidant capacity were observed between the study groups. A significant increase in serum-free T4 levels was observed in the treatment arm.

The sample size and trial duration of the recent randomized, double-blind, placebo-controlled trial may warrant further studies. However, the results indicate that certain supplementation, such as magnesium, zinc, and vitamin A, may support healthy thyroid function.

By Colleen Ambrose, ND, MAT