Not exactly a scam (the vitamins and minerals are in the bottles), but they're just not necessary and won't make you healthier or better off for the vast majority of people.
As Oliver points out this isn't even always the case! Since there is virtually no regulation, thanks Mel Gibson!
that is not really true.... How Vitamins are Regulated. Vitamin products are regulated by FDA as "Dietary Supplements." The law defines dietary supplements, in part, as products taken by mouth that contain a "dietary ingredient" intended to supplement the diet.
Any good vitamin or supplement will also be 3rd party tested USP stands for the U.S. Pharmacopeial Convention, which is an organization that bridges the gap between lack of government scrutiny of dietary supplements and the consumer's need for safe vitamins. ... The USP independently evaluates supplements for quality, purity and potency.
so you do get what is in the bottle
That is only partly true:
From NY Times
https://well.blogs.nytimes.com/2015/02/12/107141/"Last week, the New York State attorney general’s office uncovered another example of what appeared to be widespread fraud in the dietary supplement industry. The office accused four of the country’s biggest retail stores of selling herbal products that in many cases were contaminated or did not contain any of the herb listed on the label."
Regarding certification by the USP:
"For one, you can look for products that receive a seal of approval from the United States Pharmacopeial Convention, an independent, nonprofit organization of scientists that sets high standards for medicine, food ingredients and dietary supplements. The United States Pharmacopeia has a voluntary program through which supplement companies can have their products and facilities tested and reviewed.
Companies whose supplements meet the group’s standards – which ensure purity, identity and potency, among other things – are allowed to carry an official “USP Verified” seal on their labels. The group maintains an evolving list of the brands that have received its seal and the places where they can be purchased. That list can be found on the group’s website.
But keep in mind that there are some companies that print the letters “USP” on their labels without the official USP Verified seal."
Note that only a small fraction of supplements have been verified by the USP. This is the complete list of verified supplements to date: https://www.quality-supplements.org/verified-products/verified-products-listingsRegarding laws on this:
"That law – the Dietary Supplement Health and Education Act, or DSHEA – was spearheaded by legislators with strong financial ties to the industry. It allows companies to attach general health claims to their products without providing evidence of their effectiveness, and it protects supplements from the strict premarket approval rules that apply to prescription drugs."
Another article about this topic from The Atlantic (ignore clickbait URL):
https://www.theatlantic.com/health/archive/2016/06/supplements-make-tobacco-look-easy/488798/Finally, from the FDA website:
In general, the FDA regulations for dietary supplements are different from those for prescription or over-the-counter drugs.
Unlike drugs, which must be approved by the FDA before they can be marketed, dietary supplements do not require premarket review or approval by the FDA. While the supplement company is responsible for having evidence that their products are safe and the label claims are truthful and not misleading, they do not have to provide that evidence to the FDA before the product is marketed.Dietary supplement labels may carry certain types of health-related claims. Manufacturers are permitted to say, for example, that a dietary supplement addresses a nutrient deficiency, supports health, or is linked to a particular body function (like immunity or heart health). Such a claim must be followed by the words, “This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.”
Manufacturers must follow certain good manufacturing practices to ensure the identity, purity, strength, and composition of their products. If the FDA finds a product to be unsafe or otherwise unfit for human consumption, it may take enforcement action to remove the product from the marketplace or work with the manufacturer to voluntarily recall the product.
Also, once a dietary supplement is on the market, the FDA monitors information on the product’s label and package insert to make sure that information about the supplement’s content is accurate and that any claims made for the product are truthful and not misleading. The Federal Trade Commission, which polices product advertising, also requires all information about a dietary supplement product to be truthful and not misleading.
Note that the FDA requires, but does not test for, purity of the product (as is done with over the counter and prescription drugs). Not to belabor the point, but peer-reviewed studies have shown heavy metal contamination in supplements sold in China, Australia, and Lebanon. No such study has been published on supplements in the US, but they emphasize the need for strict quality controls. It's one thing to bite off a leaf of some plant and chew it, another to purify them to high concentrations (which is what most supplements purport to do). Here's an editorial article from the authors of the Australian study:
https://www.businessinsider.com/study-reveals-chinese-medicines-contain-trace-amounts-of-toxic-substances-2015-12