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Selenium and iodine supplementation in older New Zealanders
Author(s) -
Thomson Christine Dumont,
Campbell Jennifer M,
Skeaff Sheila A,
Miller Jody C,
Livingstone Vicki
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.146.1
Subject(s) - iodine , medicine , endocrinology , selenium , thyroid , thyroglobulin , hormone , placebo , iodine deficiency , glutathione peroxidase , chemistry , oxidative stress , superoxide dismutase , alternative medicine , organic chemistry , pathology
Selenium (Se) and iodine are essential for optimal thyroid hormone metabolism. Suboptimal Se and iodine status reported in New Zealanders is likely to be exacerbated in older adults. The aim was to assess effects of Se, iodine, Se plus iodine supplementation on thyroid hormones. A randomized, double blind trial was conducted with 97 subjects (73±4.8 years) with 100μg Se as selenomethionine (+Se), 80μg iodine (+I), 100μg Se and 80μg iodine (Se+I), or placebo daily for 12 weeks. Thyroid hormone status (TSH, free T 3 , free T 4 , thyroglobulin), Se status (plasma Se, whole blood glutathione peroxidase (WBGPx)) and median urinary iodine concentration (MUIC) were determined at baseline, weeks 2, 4, 8, 12. The three treatments were compared with placebo. Baseline MUIC baseline was 48μg/l (IQR, 33,72), and increased by 34μg/l in +I group (P<0.001) and 13 μg/l in Se+I group. Mean baseline plasma Se was 1.20 (0.33)μmol/l and increased by 0.99 and 0.96μmol/l in +Se and Se+I groups, respectively (P<0.0001). WBGPx increased by 9% in Se groups (P<0.001). Tg concentration decreased by 27% (P<0.001) and 18% in +I and Se+I groups. No significant time by treatment effects were observed for TSH, free T 3 , free T 4 . Older New Zealand adults are moderately iodine deficient. Their Se status is insufficient for optimal GPx activity, but appears to be sufficient for optimal thyroid hormone function. Otago Medical Research Fund.