I take a general multi vit along with some omega capsules. At the moment I am having some sea kelp tablets to help with my hair and nails which are in a terrible state.
The way I see it my non CD diet was/is so bad I dont see any harm in taking a top up. According to a nutritionist I know, the RDA's set are the bare minimum that a healthy person needs to function. Many of us are malnurished and have deficiencies therefore need more than the RDA. Obviously for some people having excess vitamins would be dangerous(liver, kidney problems).