People at times quip that my Great Grandpa did not take any supplements, and he was just fine. So why should I? Its a valid question. But remember, he probably lived with the circadian cycle waking up with the sun and going to sleep with the sun. Pesticides at that time were very limited, so he ate organic produce and organic free range healthy livestock and poultry. He didn't have a car so he was probably doing a lot of walking. The air he breathed was possibly fresher than that of a modern city. He was out in the sun more, getting a strong dose of Vitamin D. He didn't get stuck in traffic jams, getting all tensed up and stressed out. (stress depletes your nutrients)
You get the point by now, I am sure. He wasn't eating the processed junk that we tend to call food these days. Suffice it to say, if you can live like your great grandpa, than you can forget about about the supplements. Otherwise, you will have to find a different excuse. I can go on and on about the different modern day toxins that we are facing. Plastic, pesticides and herbicides, gasoline fumes, refined sugar, mercury fillings etc.
If you decide to purchase supplements, look for a good quality brand. Look for pharmaceutical grade products with reputable companies. You can test a multivitamin yourself at home. All you do is drop one in a glass of water. If it dissolves within 30 minutes then it is able to be absorbed by your body.