In 2013, vitamin and supplement sales totaled $24.6 billion dollars in the United States according to Eurovision. However, the U.S. Preventative Services Task Force announced that scientists have not found conclusive evidence that vitamin, mineral and herbal supplements suppress or fight against disease and cancer. In fact, the group found that taking vitamin E supplements may increase the risk of lung cancer in smokers. So, do vitamins really work, and which vitamins should you choose if you plan to use supplements?

The same group found that vitamin D supplements could help prevent fractures in the elderly, which sends a mixed message to people. Either supplements do not provide a benefit or they do, but it really comes down to which vitamins people take, whether they have a deficiency and where the supplement comes from. In addition, if you dislike certain foods that contain necessary vitamins and minerals, a multivitamin may help fill those deficiency holes in your diet.

Vegetarians and vegans who do not get enough B12 or iron from their diet may require supplements to maintain a healthy lifestyle. People who take cholesterol-lowering medications may also require supplements since these medications often interfere with fat-soluble vitamins. Not all studies take everything into consideration, so having a doctor perform tests for vitamin deficiencies can determine whether or not you need supplements.

Take a person with celiac disease whose body has trouble absorbing nutrients. Vitamin, mineral and herbal supplements can help reduce any deficiencies and improve overall health. A pregnant woman may also benefit from taking folic acid, which scientists agree helps to prevent birth defects. However, most nutrition experts believe that you can receive all the nutrients you need from your diet alone, and supplements can fill in the gaps. Remember, not all supplement companies produce their products equally.