Here is what I read in your article:
"Vitamin C in a sustained released form"
There are many brands of sustained release vitamin C.
Google Search "Sustained Release Vitamin C" He is also discussing cases where a person has problems absorbing iodine. Those cases are rare, per Dr. Brownstein and he also says there are other reasons for not absorbing iodine. I see his entire protocol of natural salt, Vit C, Mag, Selenium, ATP Cofactors (B2 & B3) as a shotgun to cover most of the problems involved in Iodine
absorption & helping the Iodide