Iron and thyroid

[Guest guest]

Interesting how low ferritin can affect the thyroid hormones and rT3

Asia Pac J Clin Nutr. 2006;15(1):50-5.Links

The relationship between iron status and thyroid hormone

concentration in iron-deficient adolescent Iranian girls.

Eftekhari MH, Keshavarz SA, Jalali M, Elguero E, Eshraghian MR,

Simondon KB.

Department of Nutrition and Biochemistry, School of Public Health

and Institute of Public Health Research, Tehran University of Medical

Science, Shiraz, Iran. h_eftekhari@...

Extensive data from animal and human studies indicate that iron

deficiency impairs thyroid metabolism. The aim of this study was to

determine thyroid hormone status in iron-deficient adolescent girls.

By stepwise random sampling from among all public high schools for

girls in Lar and its vicinity in southern Iran, 103 out of 431 iron

deficient subjects were selected. Urine and serum samples were

collected and assayed for urinary iodine and serum ferritin, iron,

total iron binding capacity (TIBC), thyroid stimulating hormone (TSH),

thyroxine (T4), triiodothyronine (T3), free thyroid hormones (fT4 and

fT3), triiodothyronine resin uptake (T3RU), reverse triiodothyronine

(rT3), selenium and albumin concentrations. Hematological indices for

iron status confirmed that all subjects were iron-deficient. There was

a significant correlation between T4 and ferritin (r = 0.52, P <

0.001) and between TSH and ferritin (r = -0.3, P < 0.05). Subjects

with low serum ferritin had a higher ratio of T3/T4 (r = -0.42, P <

0.01). Using stepwise regression analysis, only ferritin contributed

significantly to the rT3 concentration (r = -0.35, P < 0.01). The

results indicate that the degree of iron deficiency may affect thyroid

hormone status in iron-deficient adolescent girls.