Among adults, thyroglobulin is a useful biomarker for identifying iodine status, according to study findings published in The Journal of Clinical Endocrinology & Metabolism. Researchers noted that a concomitant decrease in thyroglobulin concentration was linked to improved iodine status evaluated by urine iodine concentration.

Sheila A. Skeaff, PhD, associate professor in the department of human nutrition at the University of Otago in New Zealand, and colleagues evaluated 112 adults aged 18 to 40 years with mild iodine deficiency to determine the effectiveness of thyroglobulin to evaluate iodine status. Participants were randomly assigned 150 µg iodine (n = 56) or placebo (n = 56) daily for 24 weeks. Participants were evaluated at 8, 16 and 24 weeks.

Median thyroglobulin was 16.6 µg/L and 8% of all participants had a thyroglobulin concentration of more than 40 µg/L at baseline.

At 24 weeks, 8.9% of the placebo group had thyroglobulin concentrations of more than 40 µg/L compared with the 1.8% of the iodine-supplemented group. The median thyroglobulin concentration decreased from 19.5 µg/L to 13 µg/L in the iodine-supplemented group but remained similar to baseline in the placebo group.

The iodine-supplemented group had lower thyroglobulin compared with the placebo group at 8 weeks (P=0.045), 16 weeks (P<0.001) and 24 weeks (P< 0.001).