Table 3

Iodine and the risk of papillary thyroid cancer among participants in the Bay Area Thyroid Cancer Study

IodineCasesControlsOR95% CI
 Dietary (μg/day)
  <2731201081.0a
  273–348921090.680.45–1.0
  349–422941090.680.44–1.0
  423–5371171090.710.45–1.1
  >5371041090.490.29–0.84
 In nails (ppm)
  <0.0874921.0b
  0.08–0.1160920.690.43–1.1
  0.12–0.1769921.00.63–1.6
  0.18–0.3564920.760.48–1.2
  >0.3558910.740.46–1.2
Among “high-risk” womenc
 Dietary (μg/d)
  <32454251.0d
  324–45752161.50.68–3.2
  >45765241.40.56–3.4
 In nails (ppm)
  <0.1035151.0e
  0.10–0.2029180.870.35–2.1
  >0.2040180.960.40–2.3
Among all other women
 Dietary (μg/d)
  <3241201551.0d
  324–4571181570.800.56–1.2
  >4571061560.530.33–0.85
 In nails (ppm)
  <0.10981611.0e
  0.10–0.20791271.00.68–1.5
  >0.20721390.790.51–1.2
  • a Adjusted for age, race/ethnicity, daily caloric intake, radiation to the head/neck, history of goiter/nodules, family history of proliferative thyroid disease, education, smoking, and alcohol consumption.

  • b Adjusted for age, race/ethnicity, radiation to the head/neck, history of goiter/nodules, family history of proliferative thyroid disease, education, smoking, and alcohol consumption.

  • c Defined as radiation to the head or neck, a personal history of goiter or nodules, and/or a family history of proliferative thyroid disease.

  • d Adjusted for age, race/ethnicity, and daily caloric intake.

  • e Adjusted for age and race/ethnicity.