After reading so many positive things about Iodine and starting on it myself, I'd like to start my 6 year old on it. How much is an appropriate dose for this age? He takes a multi-vitamin, fish oil and liquid cal-mag (500mg/250mg). I'd love to see if this would help his cradle cap that he's had since he was born. Here is what is in his multi. Would he need extra vita c and selenium like adults?