Calcium and Thyroid Health

Calcium is the most abundant mineral in the human body, essential for bone density, nerve function, and muscle contraction. Its relevance in thyroid disease is twofold: protecting bone-mineral-density and managing medication interactions.

Why Calcium Matters in Hyperthyroidism

Long-standing untreated hyperthyroidism accelerates bone turnover, reducing bone-mineral-density and increasing risk of osteoporosis and fracture. Adequate calcium intake (along with vitamin-d) helps protect bone during and after the hyperthyroid period.

Food Sources

  • Dairy products (milk, cheese, yogurt) — primary source; also high in iodine
  • Broccoli, kale, bok choy
  • Fortified orange juice
  • Semi-skimmed or skimmed milk (high in calcium despite lower fat)

Interaction with Levothyroxine

Calcium-rich foods and supplements interfere with levothyroxine absorption. A four-hour gap between calcium intake and levothyroxine dosing is recommended to prevent significant impact on blood thyroxine levels.

Supplementation

If dietary calcium is insufficient (especially on a low-iodine-diet that restricts dairy), supplementation may be necessary. Always take at least four hours apart from thyroid medication.

Sources