Iodine papers (extracted from Pharoah):

• Papua New Guinea:

  • 23: Pharoah POD, Buttfield IH, Hetzel BS. The effect of iodine prophylaxis on the incidence of endemic cretinism. Adv Exp Med Biol 1972; 30:210-21
  • 26: Pharoah POD, Connolly KJ. A controlled trial of iodinated oil for the prevention of endemic cretinism: a long-term follow-up. Int J Epidemiol 1987; 16:68-73

• Peru:

  • 30: Pretell EA, Torres T, Zenteno V, Corenjo M. Prophylaxis of endemic goiter with iodized oil in rural Peru. Adv Exp Med Biol 1972; 30:249-65
  • 31: Pretell EA, Palacios P, Tello L, Martha Wan QF, Utiger RD, Stanbury JB. Iodine deficiency and the materno-fetal relationship. Pan Am Health Org Sci Pub 1974; 292:143-55

These aren't a priority. I think it's highly likely that iodine will do little for adult intelligence, and I'm mostly pursuing this line of inquiry so I can do a meta-analysis (for practice - this would be only my second one, after the n-back one) and nail down the experiment design a little more tightly.