Many of my patients come in with a shopping bag full of supplements at the first visit.

“Why are you on this?” I ask about each one in turn. “Oh, I read it was good for my heart I think,” they tell me, or, “Doesn’t that help my thyroid?” or, “I’m post-menopausal, so I’m trying to prevent X,” or “You know, I can’t remember now! My other doctor told me to take it so I just take it!”

As a general rule, I’m a “less is more” kind of a girl. I’m all for the judicious use of supplements when we’re trying to correct an imbalance or prevent disease when diet alone isn’t enough (which, unfortunately, it isn’t)—but emphasis on judicious. More often than not, when someone comes in on a shopping bag full of supplements and we eliminate those that aren’t necessary, the patient feels better. This is true across the board, but it’s especially true when the products in question come from pharmacies or box stores (which shall remain nameless). I strongly suspect that this is because of all the additives in the supplements.

Supplement Additives and What They Do

Additives fall into several basic categories, sorted according to function. Here are the big ones:

Fillers and Bulking Agents. These do what it sounds like: they make the tablet or capsule look like it has more stuff in it. (I’m not sure why this is desirable, since many of my patients dislike swallowing large pills!) Here are some of the common ones:

  • Soybean oil. This is partially hydrogenated, and it’s also genetically modified unless otherwise stated.
  • Magnesium stearate. The controversy here isn’t over the magnesium, but over the stearate, or stearic acid. The latter was linked in this study to reduced T-cell function.
  • Titanium Dioxide. This filler can cause DNA damage and intestinal inflammation.
  • Corn starch. Unless otherwise specified, corn or corn products are GMO in the US. That’s a good enough reason to avoid it.
  • Corn maltodextrin. Ditto above.
  • Stearic Acid. As with magnesium stearate, this was linked in this study to reduced T-cell function.
  • Citric acid: usually derived from GMO corn.
  • Cellulose powder. This is derived from wood pulp.

Binders. These help ingredients stick together. (In a recipe, it would be like the eggs.) Here’s the ones usually used:

  • Modified food starch. This is almost always from corn, which means it’s GMO unless otherwise stated.
  • Sucrose. This is table sugar. It’s not enough that it’s in all prepackaged foods—now it’s in supplements too! Plus, it’s usually GMO.
  • Polyethylene glycol. Derived from petroleum, this is made from ethylene glycol (aka antifreeze.)
  • Sorbitol: These are sugar alcohols. If you’re very sensitive to FODMAPs, they aren’t a good choice, but otherwise the small amount you’d get in your supplement likely isn’t enough to cause bloating.
  • Xylitol: Ditto above.

Anti-caking agents. These absorb excess moisture, and prevent clumping.

Emulsifiers: These help water and fats to combine.

Preservatives: These give the ingredients a longer shelf life.

  • Ascorbic acid: although this is vitamin C, most of it is made from GMO corn unless otherwise stated.
  • Sodium benzoate. Benzene is a byproduct of this one—a known carcinogen.
  • Sulfites. These can cause severe asthma reactions in sensitive individuals.  They are also a relatively common trigger for migraines.
  • Sodium ascorbate. This is made from GMO corn unless otherwise stated.
  • Ascorbyl palmitate. Ditto above—also made from GMO corn unless otherwise stated.
  • Nitrates or nitrites. In the body these form carcinogenic (cancer-causing) nitrosamines.
  • Sodium citrate. Usually derived from GMO corn.
  • Citric acid. Usually derived from GMO corn.

Artificial Colors and Flavors. Just like in food, these are added to make the product look and taste more appealing. I wrote here on the colors that often show up in foods, and why you should avoid them. Same rules apply.

Artificial Sweeteners. These, of course, are added to improve flavor. I wrote here on common sweeteners in foods—the same ones show up in supplements. Some are ok… some, not so much.

The Upshot

As with foods, read your labels. Buy from suppliers you trust, who source their ingredients from non-GMO sources. Avoid supplements with a long list of “inactive ingredients” on the back.