And this one is a "good" one...
What they have in common is that they are all completely useless. A study from the International Journal of Preventive Medicine showed that multivitamin supplements (MVM) are completely unnecessary for one’s health and stated that “...although in the long run MVMs may slightly increase the risk of cancer and cardiovascular diseases, in the short run they produce little harm or no harm, and thus negative consequences will not be discernible by individuals taking them.”
However, since the publication, one claim has drastically changed. Negative consequences in the short run have become discernible. More than 20,000 emergency room visits a year can be traced back to dietary supplements. Many of these visits include children taking adult supplements, likely due to confusing adult pills for their own pills. But these pills shouldn’t be in people’s homes in the first place.
Pseudoscience and irresponsible advertising keep unwitting customers hooked. For example, at the first sign of a sniffle and a sneeze, many people reach for their nearest Vitamin C supplement, sold by companies with snappy names like Emergen-C. But Vitamin C has never been proven to have curative effects on the common cold. In fact, far from preventing a cold, overdoses of Vitamin C can cause diarrhea and nausea. But the damage of their initial marketing had already been done, and Vitamin C has become a staple ineffective home remedy for the cold.