Thyroid Scan ...3 weeks with no Multi Vitamin?

I'm scheduled for a Thyroid Scan on Feb.28th 2017 2 days of testing,  I was just diagnosed with many small Nodules in my Thyroid this week.I take this Pill on day 1 that has Iodine and lots of Sodium in it.Checking my Nodules in my Thyroid. Im given these rules I need to abide by, one whi*****ludes me to not take my multivitamin for 3 weeks prior to testing. I have never went one day without taking my multivitamins. I also have to be on a very strict low sodium / low Iodine Diet for 3 weeks. Has anyone went 3 weeks or more without taking their multi vitamins? Will I see a difference in my moods, health because of my what ever else can happen with Rny people out 8+ years Post op? Im panicing because I have went 2 days without my calcium citrate and my back was literally burning. The doctor knows I had Rny. I've also been loosing my teeth...

Thanks for any input on this. Wendy

I have a thyroid scan on Feb 21 and am off of multi-vitamins and thyroid pills for 30 days.  I don't notice any difference, but my vitamin levels were good starting this.