Recently, there has been a growing interest in the pharmaceutical industries to incorporate deuterium in drugs candidates to improve their metabolism and pharmacokinetic properties such as Deutetrabenazine (Austedo®). 
Soulard et al. have developed a selective method to deuterate iodides using D2O as cheap and easy available source of deuterium.  The reaction is catalyzed by a thiol and did not require any (transition) metal to give high yields and deuterium incorporations.
This work was carried out in the group of Prof. Philippe Renaud.
"Deuterated drugs draw heavier backing"
Nat. Rev. Drug. Discov., 2016, 15(4), 219-221;
V. Soulard, G. Villa, D. P. Vollmar, P. Renaud;
"Radical Deuteration with D2O: Catalysis and Mechanistic Insights"
J. Am. Chem. Soc., 2018, 140(1), 155-158;