Side Effects of Vitamins & Supplements

I have two questions concerning vitamins and supplements I started taking:

1. Is it possible to experience detox symptoms (fluoride, chlorine, etc) when taking Kelp iodine? About a week ago I started taking Nature's Way Kelp Capsules (400mcg of Iodine per capsule). Initially I was taking one capsule and started taking two capsules two days ago. Since I started taking it I have developed a sore throat and chest congestion. Is this normal at such a low dosage?

2. Last night I became extremely sick. I had terrible stomach cramps and ended up vomiting. This occurred about 5 or 6 hours after I took my nightly supplements (with dinner). The supplements I take in the evening are Sundown Triple Magnesium Tablet (500mg), Ester-C 24 Hour Immune Support (500 mg), a B complex, Gaia Herbs Adrenal Health Liquid Phyto-Capsules, and Optimum Nutrition Opti-Women Women's Multivitamin. I have been taking all of these except for the magnesium (first time taking the magnesium) for a couple of days with no problem. Could the magnesium have caused this? Or maybe some sort of reaction to the mixture of the supplements? Or possibly the iodine?

Thanks!