I don't know about gram size; only took it only a couple of times. But been steady good for 10 years on 150 mg (not mcg) of Iodine taken with vit C. Lately not daily, more like every other day. the vit C / juice transform the Iodine to an anti oxidant form semi like potassium iodide, so no worries. Selenium; maybe up a bit unless you live in an area with plenty in the soil.