Selenium status in a Northern Irish pregnant cohort with iodine deficiency

Selenium and iodine are trace elements that are maximally concentrated in the thyroid. Iodine is a substrate for thyroid hormone synthesis, while the selenoproteins protect the thyroid from the oxidative stress incurred. We measured plasma selenium concentration in 241 pregnant women in 1st trimester, previously reported to have iodine deficiency. Mean age was 30.3 years (SD 5.4), BMI 26.2 kg/m(2) (SD 4.9) and 53% reported taking supplements. Median urinary iodine concentration was 73 mu g/L (IQR 37-122) (WHO recommendation, >= 150 mu g/L). Mean plasma selenium concentration was 75 mu g/L (SD 7.7) which is below the 80-125 mu g/L reported to be optimal. Four-day food diaries revealed a selenium intake of 43 mu g/day (SD 15.9), also below the 55-70 mu g/day reported to be optimal. This is the first report of selenium status in pregnancy on the island of Ireland. The possible combined effects of iodine and selenium deficiencies in pregnancy merit further investigation.

Automated summary

Selenium and iodine are essential for thyroid function, with selenium protecting the thyroid from oxidative stress and iodine being a substrate for hormone synthesis. Research on pregnant women with iodine deficiency showed suboptimal selenium levels, indicating a possible coexistence of selenium and iodine deficiencies that warrant further investigation.