New evidence

A meta-analysis found zinc, magnesium, and vitamin A raised free thyroxine by a large margin (SMD 1.95) in hypothyroidism — but the evidence rests on 508 patients and the dose wasn't specified.

This is early, promising evidence that a specific nutrient combo might help increase thyroid hormone levels in people with hypothyroidism already on levothyroxine, but the finding comes from a single meta-analysis with a small sample and no dosing details, so it’s far from ready for real-world use.

Researchers pooled data from 508 people with hypothyroidism on levothyroxine therapy and found that adding a supplement blend of zinc, magnesium, and vitamin A led to a significant increase in free thyroxine (FT4), a thyroid hormone that regulates metabolism. The same analysis also saw a rise in another thyroid hormone, free T3. However, this is among the first systematic reviews to examine this combination, and the lack of dose information means the results need replication before any practical recommendations can be made.

Where this fits in the evidence

This is among the first studies we've indexed on Zinc for Increased Serum Free Thyroxine Levels — treat it as an early signal until more research accumulates.

The study

Additional treatment strategies for hypothyroidism: a network meta-analysis.

Systematic Review
n = 508
2026-03-13
Endocrine connections

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