After my daughter's celiac diagnosis, I cleared the kitchen, then opened the vitamin bin. I found tablets with "starch" listed as a filler, capsules with "malt extract," and a gummy that listed "natural flavors" without a source. I had spent years reading food labels, but I had never read a supplement label closely. That started a research stretch that changed how I buy every pill and powder in our house.
I am not a clinician or a dietitian. I am a mom who reads labels, calls manufacturers, and keeps notes on my phone. This is what I learned from digging into the history, the law, and the fine print.
A Short History of Pill Fillers
Tablets and capsules need materials to hold their shape, help powders flow through filling machines, and control how fast they dissolve. For most of the twentieth century, the default fillers were starches and sugars. Corn starch, potato starch, rice starch, and sometimes wheat starch all did the job. The ingredient list often said "starch" without naming the plant source. That told a consumer nothing about gluten.
The Dietary Supplement Health and Education Act of 1994 created the modern supplement category in the United States. It defined supplements as food, not drugs, and put responsibility for safety and truthful labeling on manufacturers. But DSHEA didn't require premarket approval. A company could use a wheat starch filler and, under the labeling rules of that era, sell the bottle without any gluten-related warning.
The 2004 Labeling Gap
The Food Allergen Labeling and Consumer Protection Act of 2004 made wheat a labeled allergen. FALCPA requires packaged foods and dietary supplements to declare the eight major allergens by plain name. Wheat starch must appear as "wheat starch." That helped.
But FALCPA has a blind spot. Gluten is a protein found in wheat, barley, rye, and some crossbred grains such as triticale. Wheat is a major allergen, so it must be declared. Barley and rye aren't major allergens under FALCPA, so ingredients derived from them don't have to be called out. Malt extract, malt syrup, and malt flavoring often come from barley. If a label lists "malt extract" without a source, a person with celiac disease can't tell from the label alone whether the product contains gluten. "No wheat" does not mean "gluten-free."
The 2013 Gluten-Free Rule
In August 2013, the FDA finalized a rule that defines "gluten-free" for food labels. Dietary supplements are included. A product labeled gluten-free must contain less than 20 parts per million of gluten. That threshold comes from the FDA's safety assessment and the limits of available testing methods.
The rule doesn't require a manufacturer to test a supplement before putting "gluten-free" on the label. The FDA doesn't approve supplement labels before they go to market. So the claim is a legal promise, not a certification. A company can make the claim and be responsible for making sure its product stays under 20 ppm, but the testing schedule is up to the company. Some manufacturers test every batch; some test less often.
And a supplement without a gluten-free claim can still contain wheat starch, barley malt, or rye-derived ingredients. The label can be legal and still be a problem for my daughter.
What I Check on Every Bottle
I read every label twice now. Here is the order I follow.
- I look for the words "gluten-free" on the front or back. That is the only claim with a legal definition. If it is absent, I don't assume the product is safe.
- I read the "Other Ingredients" section. I look for the words "starch," "modified food starch," "pregelatinized starch," "dextrin," "maltodextrin," "malt extract," "malt syrup," and "natural flavors." If the starch source isn't named, I call or email the company and ask.
- I check for brewer's yeast. Some supplements use brewer's yeast for B vitamins, and brewer's yeast is sometimes grown on barley. I avoid it unless the bottle says gluten-free.
- I keep a note on my phone with the manufacturers who answered my questions and the ones who didn't. That list decides which bottles come home.
I also look for short ingredient lists. For protein powder, I use Clean Monday Meals plant-based protein because the label lists eight ingredients I can pronounce and the product is gluten-free, dairy-free, and soy-free. It replaced a shelf of powders with ingredient lists I couldn't trace. That is my personal standard, not a medical recommendation. If you or your child has celiac disease, talk to your doctor or dietitian about supplement choices and cross-contact.
What I Hope Changes Next
The history here is a series of partial fixes. DSHEA in 1994 created the supplement category. FALCPA in 2004 made wheat visible. The FDA's 2013 rule gave "gluten-free" a legal meaning. Each step closed one gap and left another.
The gap I want closed next is barley and rye. I want labels to name the plant source of every starch, malt ingredient, and flavoring. I also want more manufacturers to test every batch and print the results on the bottle or a QR code. A few companies already do this, but it isn't the standard. Until it is, I will keep reading the small print, keep calling when I have a question, and keep teaching my daughter to do the same.
If you are new to this, start with the "Other Ingredients" box and the gluten-free claim. Those two things tell you more than the front of the bottle ever will. You don't have to figure it all out in one afternoon. One label at a time is enough. And if you want to share what you've learned or ask a question, find us on social at @cleanmondaymeals. We're all figuring this out together.