Consumers assume that all supplements are health promoting because of the virtual nature of what they are made to do. In reality this is not true at all. The supplement business is BIG business, worth over $60 billion U.S. dollars and it is regulated by the Dietary Supplement Health and Education Act or DSHEA, http://npainte1.hubpages.com/hub/Should-Diet-Supplements-be-regulated-more-strictly. However, many of the safety and efficacy tests on supplements are completed by the same company that manufactures them.
I always believe in reading labels on food and the same is true for supplements. Take the time to do a little homework. Find a reliable brand that works for you. Do not just fall victim to clever marketing schemes.
Just like the unhealthy ingredients from so-called “health foods”, not all “healthy” supplements are created equal. Â Supplements can contain harmful substances that may not be listed on the label. According to Natural News http://www.naturalnews.com/039638_toxins_ingredients_nutritional_supplements.html, there are more than just a few hidden toxic substances in many substances, including:
1. Maltodextrin a common additive in foods is derived from genetically modified corn
- look for “Certified USDA organic “or tapioca  maltodextrin or avoid products with maltodextrin as best as possible
2. Ascorbic acid also derived from genetically modified corn
- try to avoid supplements containing Vit. C or ascorbic acid
*GMO‘s  have been banned in France and Russia after a study (most studies on GMO’s are short-term, this study was 2 years) found that genetically modified foods were linked to kidney and liver damage and breast cancer, http://www.dailymail.co.uk/news/article-2208452/Russia-suspends-import-use-American-GM-corn-study-revealed-cancer-risk.html.
Activists in the state of California have  proposed to have GM products from the US food supply removed. They lost the fight against Monsanto to pass Proposition 37, a law requiring labels on GM foods, http://www.huffingtonpost.com/2012/11/07/prop-37-defeated-californ_n_2088402.html.
3. Hexane is a derivative of crude oil and used to extract protein from rice and soy. It is also used to extract vegetable oil from plants because the process helps to contain costs and increase profits.
The EPA estimates the consumption of less than 0.06 milligrams hexane per kilogram of body weight is probably safe but I’d rather not ingest any, http://nutrition.about.com/od/ahealthykitchen/f/hexane.htm.
4. Heavy metals: aluminum in “Detox” products and lead, arsenic, mercury, iron and cadmium for various reasons.
5. Yeast extract contains MSG and is found everywhere except products labeled “no yeast”. Hidden MSG is also labeled as “autolyzed yeast extract” or “torula yeast” or even “hydrolyzed vegetable protein.” MSG provides more sodium in your diet and can contribute to migraines.
Cheaper supplements may be more costly to your health and your pocketbook because many times the vitamins or minerals used may not be used by your cells or have additives that will have a negative impact on your health. Know your supplement companies. Use supplements from companies that are reputable, third-party tested and follow good manufacturing practice (GMP should appear on the label). Hint: Popular does not mean better.