By Antonella Maggio, Director of Quality Services, SGS Nutrasource
As the dietary supplement industry continues to evolve, maintaining product quality and regulatory compliance requires more than strong internal processes. Brands must also understand and manage the quality practices of the suppliers, manufacturers, and other third-party partners involved throughout the supply chain in bringing their products to market.
Vendor audits are an important part of this responsibility. They provide an opportunity to evaluate whether external partners have the appropriate quality systems, controls, and procedures in place to consistently meet established requirements. More importantly, they help organizations identify potential risks before they affect product quality, consumer safety, or business operations.
However, an effective vendor audit should go beyond checking documents and confirming that procedures exist. It should provide meaningful insight into how a supplier operates, how quality is managed in practice, and whether the organization can demonstrate consistent control over its processes.
Understanding the Purpose of Vendor Audits
Vendor audits are a fundamental component of supplier qualification and ongoing quality oversight. For dietary supplement brands, they can help assess the capabilities and compliance practices of contract manufacturers, ingredient suppliers, packaging providers, laboratories, and other critical vendors. Vendor audits represent a pathway for routine risk-based monitoring and can offer a deeper insight, and an opportunity to create strong partnership with your suppliers.
While regulatory requirements and industry standards establish expectations for quality and manufacturing practices, organizations remain responsible for exercising appropriate oversight across their supply chains.
A well-structured vendor audit helps establish whether a supplier's documented quality systems are effectively implemented. This includes evaluating areas such as:
- Quality Management Systems (QMS): Assessing whether documented procedures, responsibilities, training programs, and quality controls are established and maintained. It also provides feedback on how the Quality Culture is sustained.
- Manufacturing and Operational Controls: Reviewing production processes, sanitation practices, equipment maintenance, and measures to prevent contamination or product mix-ups.
- Equipment, Process and System Controls: Evaluating whether equipment, processes and systems are adequate to support specific manufacturing operations while integrating risk management and continuous improvement.
- Documentation and Recordkeeping: Evaluating the accuracy, completeness, and traceability of batch records, specifications, testing documentation, and other quality records.
- Deviation and CAPA Management: Determining how nonconformances are investigated, root causes are identified, and corrective and preventive actions are implemented.
- Supplier and Material Controls: Reviewing how incoming materials are qualified, tested, approved, and monitored throughout the supply chain.
A robust and integrated Quality Management System provides valuable insight into a facility’s level of maturity, particularly when management review processes include ongoing evaluations of system effectiveness, risks, and opportunities for improvement.
The specific scope of an audit should reflect the materials or services being provided along with any relevant history, the applicable standards and regulations, and the potential risks associated with the products involved.
Moving Beyond Compliance: Taking a Risk-Based Approach
Not all vendors present the same level of risk, and audit programs should reflect this.
A risk-based approach allows organizations to prioritize their audit resources based on factors such as the criticality of supplied materials, the complexity of manufacturing processes, the vendor's compliance history, and the potential impact of a quality failure.
For example, a contract manufacturer responsible for producing finished dietary supplement products may require a more comprehensive audit than a supplier providing a lower-risk ancillary service. Similarly, a vendor with a history of recurring quality issues may warrant increased oversight or more frequent assessments.
Organizations should also consider when audits are conducted. Initial qualification audits help establish whether a vendor is suitable before entering into a business relationship. Periodic audits provide ongoing oversight, while for-cause audits or routine follow-ups may be appropriate due to significant deviations, recurring complaints, regulatory observations, or other concerns.
This approach helps ensure that audit frequency and depth are proportionate to the associated risks rather than relying on a one-size-fits-all schedule.
Common Gaps Identified During Vendor Audits
In practice, many quality concerns are not necessarily the result of missing procedures. They arise when documented procedures are not consistently followed, responsibilities are unclear, written steps do not have the appropriate detail to meet a standard/requirement, or quality systems lack the oversight needed to remain effective.
Some common areas of concern include inadequate documentation, incomplete investigations, insufficient root cause analysis, and corrective actions that address immediate issues without preventing recurrence.
CAPA management is particularly important in this context. Identifying a problem is only the first step. Organizations must also evaluate why it occurred, determine whether similar issues may exist elsewhere, and establish appropriate actions to address the underlying cause.
Another area that deserves attention is Change Control. Changes to manufacturing processes, raw material suppliers, specifications, equipment, or facilities can introduce new risks if they are not appropriately evaluated, documented, and communicated. Depending on the nature of the change and the applicable submission, regulatory notification or approval may also be required.
These findings reinforce why vendor audits should assess the effectiveness of quality systems, not simply whether the required documentation is available.
Turning Audit Findings into Meaningful Improvements
The value of a vendor audit is ultimately determined by what happens after the assessment.
Audit findings should be clearly documented, categorized according to their significance, and communicated to the vendor with defined expectations for resolution. Depending on the nature of the findings, this may involve requesting additional documentation, conducting a root cause investigation, implementing corrective actions, or scheduling a follow-up assessment.
Organizations should also evaluate the adequacy and effectiveness of proposed corrective actions. A completed CAPA form does not necessarily demonstrate that an issue has been resolved. Evidence should support that the identified cause has been addressed and that appropriate measures are in place to prevent recurrence. As such, CAPA effectiveness verifications may also be warranted.
Maintaining an organized record of audit findings, vendor responses, and follow-up activities also helps organizations identify recurring trends and evaluate supplier performance over time through scorecards or other tools.
This creates a more proactive approach to quality management, where audits become part of an ongoing improvement process rather than an isolated compliance exercise. After all, an audit provides only a snapshot of performance at a specific moment, while operational realities continue to change over time.
Building a Stronger Quality Management Framework
Managing vendor relationships and maintaining effective audit programs can be challenging, particularly as organizations expand their product portfolios, enter new markets, and work with increasingly complex supply chains.
A strong quality management framework helps bring consistency to these activities. This includes establishing clear vendor qualification criteria, maintaining appropriate audit schedules, defining responsibilities, and ensuring that findings are tracked through to resolution.
For organizations that do not have extensive internal quality resources, external expertise can also provide valuable support. Independent quality assessments can offer an objective perspective on existing systems, identify potential gaps, and help organizations prioritize improvements.
At SGS Nutrasource, Quality Services supports companies across the dietary supplement and natural health product industries in strengthening their quality management practices. Services include quality management system support, regulatory and quality audits, audit preparation, CAPA guidance, and practical consultation on manufacturing best practices.
Through a combination of technical expertise and industry experience, the goal is to help organizations better understand their quality obligations, address identified gaps and establish processes that support consistent quality oversight.
Ultimately, vendor audits should be viewed as more than a regulatory requirement or supplier qualification exercise. When approached strategically, they are an important tool for managing supply chain risk, strengthening vendor relationships, and supporting the long-term quality and integrity of dietary supplement products
About the Author
Antonella Maggio is the Director of Quality Services at SGS Nutrasource, where she works with organizations across the dietary supplement industry to support quality management, regulatory compliance, and continuous improvement. Her work focuses on helping companies strengthen their quality systems, navigate audit requirements, and implement practical approaches to quality oversight.