Vitamin and mineral supplements. You only need supplementation if you have a specific deficiency, and deficiencies are not extremely common. Most people who take supplements do not need them and are just peeing out all the extra things they're putting in their bodies while shelling out ridiculous prices to "natural remedy" companies.
If you think you have a deficiency, explain why to a doctor. A blood test to know for sure is simple. A doctor will know what kind of supplementation would best serve you, and there may be an underlying reason that can be treated to fix it. Also eat some god damn vegetables you fat little piggy