Dear They Said What? nation,

Occasionally we re-post from Quizzify here. This particular posting was quite popular, so we thought it worthy of a repost. Also quite popular on The Skeptical Cardiologist, which is one of our favorite blogs. If I knew how to create a blogroll, they would be on it.

The majority of your employees take nutritional supplements, whose consumption just reached an all-time high. That increase means someone, somewhere – maybe even your very own wellness vendor – is telling them this is a good idea.

Or maybe they are thinking: “Hey, what harm can they do?”

Plenty, as it turns out. Here are six things employee should know about nutritional supplements. In the case of close calls, we yield to the optimistic views of the supplementarians, on the theory that they are more likely to whine and we don’t want to get into any he said-she said comment fights with them.

1. Most benefits of supplements with none of the risk can be achieved with a regular multivitamin

There is plenty of evidence for the health benefits of virtually all vitamins and minerals and even a couple of supplements, so much evidence that we have room to highlight only a few.

Examples include fish oil for menopausal women with dry eye or possibly people at high risk of heart attack. Or folic acid for pregnant women and iron for pregnant women who are anemic. Or Vitamin D for people who have dark skin, live in cloudy climates, avoid all sun exposure and/or don’t each much dairy. And of course, Vitamin B12 for vegans. (Vitamin B12 is found only in animal products.)

Women likely benefit from small combined extra amounts of calcium and Vitamin D…but as noted below, don’t overdo it.

The 10% of the population who drink to excess really should be taking daily multivitamins. This is partly because alcohol interferes with absorption, and partly because they aren’t getting enough calories from real foods.

With these exceptions, most people should be getting enough vitamins in a balanced diet, but a few cents a day of an “insurance” multivitamin pays for itself just in the psychological benefit of not worrying about that. However, the story changes when we talk about megavitamins, and especially when we talk about other supplements.

2. Almost every megavitamin which once showed “promise” in fighting cancer, heart disease, etc. doesn’t. Quite the opposite, they may cause harm.

Niacin, once thought to have magical properties against heart attacks, has been completely debunked. Vitamin E supplements could prevent cancer in some women but cause it in others, depending on genes. Men who are concerned about prostate cancer (meaning all of us) should specifically avoid Vitamin E supplements, which likely increase the odds of it. Vitamin D in large quantities is the latest to be debunked, just last month. Taking too much may cause osteoporosis, rather than prevent it.

As with anything else for sale on the web, there is a business model here that may not always be in the consumers’ best interest. This is particular true for Vitamin D, where the “Doctor” who touts the stuff the most gets paid handsomely by the industry.  He thinks the dinosaurs didn’t die due to the asteroid that hit the earth. He thinks they died of a Vitamin D deficiency due to the lack of sunshine afterwards.

And monitor your own wellness vendors. Interactive Health, for example, tests every employee for anemia.  (See “Interactive Health breaks its own record for stupidity.”)

This is contrary to the advice of clinical guidelines, which oppose anemia screening except for pregnant women, where evidence is mixed. Employees who then take iron supplements risk stomach pain, nausea, vomiting and serious long-term complications.

The good news? It is just slightly possible large amounts of Vitamin C do offer modest benefits with respect to common colds, and that those possible benefits outweigh the possible harms. But just large amounts, like 200-400 mg., not massive amounts. Not the 1000+ mg. that the proponents tout. 

3. If you have to go to GNC to obtain a supplement, or order it through the mail, it has no value and may cause harm.

CVS and Whole Foods want to make money too, and fancy supplements are expensive, high-margin items. So if a supplement has even the slightest inkling of value, they’ll stock it.

As a random example we picked because we like the name, consider horny goatweed, as a treatment for erectile dysfunction (ED). Along with the name, it also has a great back story, something about Mongolian herders observing goats getting aroused after grazing on it.

Horny goatweed is actually proven to work, though — and not just on goats. It also works on rats. For the rest of us mammals, there is zero evidence. Plus, ED is one of those conditions where, if something worked, we’d know about it by now.

At least the likelihood of harm is pretty low to other than your wallet.

4. There is no such thing as FDA approval for supplements

Supplements are notorious for lax quality control, unproven health claims, and contamination. Did we mention unproven claims? The FDA has no say in the matter of unfounded health claims.

It’s also not entirely clear that these pills contain the ingredients they claim to contain in the quantities they profess to contain. These supplements turn out to be much harder to manufacture to specs than regular synthetically derived pills.

5. They may interact with “real” drugs you are taking

Just because supplements are derived from natural sources doesn’t mean they don’t act like real drugs inside your body. And, like real drugs, they can interact with other drugs. For instance, if you are taking Vitamin E and Advil or Advil PM or a baby aspirin, your risk of bleeding profusely in an accident goes way, way up, because all are blood thinners. The risk isn’t just accidents — small everyday bruises may become big bruises.

Make sure you list supplements when describing to your doctor what you take…though it’s questionable whether (aside from the basics, like that blood-thinning example) the doctor would be aware of these interactions. There are too many to track, and some interactions simply aren’t studied.

It all comes back to this: a one-a-day multivitamin/mineral supplement is more than enough for most people. Not just for the benefits, but for avoidance of the risk of interaction, side effects and unknown long-term impacts.

6. There is one “supplement” that benefits almost every body system and has no side effects

You guessed it – exercise, the key to health and longevity. If there were a dietary supplement that provided even a small fraction of the benefits of exercise with none of the work, we’d know about it by now.