I usually took it once a day in the evening before bed but with the lower doses to begin with I often took an extra one earlier in the day.
I took several vitamins and minerals, C, E, B complex, a Calc mag zinc tab and selenium also fish oil and some glutamine. that's about all I think. About a gram of C and all the vitamins well separate from the Miracle-Mineral-Supplement by 4 hours at least.
I live in the UK and got my Lugol's from Nutricentre.com online, in the US most seem to get it from J Crows