Quality and safety of dietary supplements: why testing for pesticides and heavy metals is essential

2. What does science say?

Scientific literature shows that dietary supplements regularly contain traces of pesticides and heavy metals. Studies by Jairoun et al. (2022), Sharma et al. (2020) and Ernst (2002) indicate that long-term exposure to these substances can be harmful, even at low doses.

Risks cited in studies include:

• Kidney and liver load
• Neurological damage
• Increased cancer risk from exposure to certain pesticides
• Hormonal disturbances (e.g., endocrine disruptors)

3. Regulation and supervision

In the EU, maximum residue limits (MRLs) for pesticides are set in Regulation (EC) 396/2005. For food supplements, only a notification requirement applies in the Netherlands. That means: the products do not have to be assessed or approved in advance. Control by the NVWA is random, which leaves room for risk.

4. Markthiates

Many manufacturers limit testing to the legally required parameters. Often they do not test for:

• Pesticide residues
• PAHs (polycyclic aromatic hydrocarbons)
• Persistent organic contaminants (such as PCBs and dioxins)

In addition, suppliers are rarely audited, and batch-by-batch traceability is lacking. This means that even brands that claim “natural” or “pure” cannot always demonstrate that their products are free of harmful substances.

5. Independent Eurofins testing.

Kala Health works with Eurofins, an ISO-accredited laboratory. Here, all of our products are tested for such things as:

6. Supplier audits

Kala Health conducts on-site quality audits of its raw material suppliers. In doing so, we check, among other things:

• Origin and growing conditions
• Processing and storage protocols.
• Documentation and laboratory data

Thus, we ensure that each batch is traceable and responsibly produced.

7. FSSC 22000 assurance.

Our production facility in the Netherlands is FSSC 22000-certified. This means, among other things:

• Full implementation of HACCP
• Regular external audits
• Continuous improvement of food safety management

8. Cumulative exposure

Exposure to small amounts of pollutants appears harmless, but can lead to accumulation with daily use. This is particularly true of:

• Cadmium (kidney load)
• Arsenic (carcinogenic with long-term exposure)

9. Synergistic effects

When multiple pollutants are present simultaneously, they can amplify each other’s toxic effects. For example, combinations of heavy metals and pesticides have been found in research to increase cellular stress and oxidative damage.

10. How does this benefit consumers?

• Assurance of the absence of harmful substances
• Confidence in transparent production and provenance
• Access to certificates of analysis (COAs).
• A conscious choice for quality and health

On health claims and our limits as a brand

Although many of our ingredients have been extensively researched, due to European legislation we are not allowed to mention on this website all the health benefits shown by scientific studies.

Would you like to know more about our products or formulas? We are happy to think along with you without any obligation.
Call us at (+31) (0)70 345-0290

About the author: Jesse

What I value most about my job is that every day I can contribute to promoting products that I fully support. The science and quality behind our nutritional supplements motivate me to make sure as many people as possible get to know them.

I feel at home in a team with a clear vision, that takes responsibility and has a passion for health and wellness. I have a BSc in Health Sciences from the University of Twente. I combine this background with a master’s in marketing, focusing on transparent, substantive communication. No empty claims, but sharing knowledge: building a relationship based on trust and expertise.