It has not been scientifically established that large amounts of vitamins and minerals or dietary supplements help prevent or treat health problems or slow the aging process. Daily multivitamin tablets can be beneficial to some people who do not consume a balanced diet or a variety of foods. Generally, eating a well-balanced diet with a variety of foods provides the necessary nutrients your body needs. Eating whole foods is preferable to supplements because foods provide dietary fiber and other nutritional benefits that supplements do not. If you choose to take vitamin and mineral supplements, it is recommended to choose a multi-vitamin that does not exceed 100 percent of the Recommended Dietary Intake (RDI).
However, some herbal supplements may not be safe. They could contain unlisted ingredients that make you sick. Drugs that aren’t listed on the label can include, steroids or estrogens. Products may even contain toxic, or poisonous, substances. Examples include, as arsenic, mercury, lead, and pesticides. Supplements must be recalled if they are found to contain toxic ingredients.
The European Union's (EU) Food Supplements Directive of 2002 requires that supplements be demonstrated to be safe, both in dosages and in purity. Only those supplements that have been proven to be safe may be sold in the EU without prescription. As a category of food, food supplements cannot be labeled with drug claims but can bear health claims and nutrition claims.
Talk to your doctor if you don’t think you’re getting enough vitamins and minerals in your diet. They can help you decide which micronutrients you need. They also can recommend a dietary supplement. This will depend on your overall health and lifestyle. Supplements can cause problems with cancer treatments or surgery. Your doctor will know if they interact with any health conditions you have.
For example, while increased consumption of fruits and vegetables are related to decreases in mortality, cardiovascular diseases and cancers, supplementation with key factors found in fruits and vegetable, like antioxidants, vitamins, or minerals, do not help and some have been found to be harmful in some cases. In general as of 2016, robust clinical data is lacking, that shows that any kind of dietary supplementation does more good than harm for people who are healthy and eating a reasonable diet but there is clear data showing that dietary pattern and lifestyle choices are associated with health outcomes.