Contrary to popular belief, not everyone needs a supplement — a lot of people get the nutrients they need from a healthy, balanced diet. So, the first step is to understand if you need to take one.
Depending on your diet, you may need to take certain supplements to cover off nutrients you aren't getting from food. Or, if a blood test shows you are deficient in a certain nutrient, a supplement might be required to replenish your body's stores.
Read more here.