A friend told me she'd lost weight by taking kelp plus Omega 3s. I don't know if I had an iodine problem but kelp is very nutritious anyway, so it makes a good supplement and I thought I'd try it. I'm not taking any Omega 3 at the moment, just CO first thing and a kelp tablet after lunch and dinner. Seems to be working, I've lost a couple of pounds this week.
I don't think the metabolic effect is spectacular but kelp also contains iron, sodium, phosphorus and calcium, as well as magnesium and potassium. Kelp is a source of vitamins A, B1, B2, C, D and E, plus amino acids. Because the plantís nutrients come in a natural form, they are easily assimilated by the body.
You can buy powder and it's good to add a teaspoonful to soups etc but (I think) it tastes yukky on its own, so tablets are easiest.