GMP, or Good Manufacturing Practices, is a set of manufacturing guidelines which the FDA requires makers of pharmaceutical products, foods and devices to follow. The FDA uses these guidelines to hold vitamin and dietary supplement makers accountable in creating supplements. Under the law, makers are required to ensure their processes are controlled and evaluated for quality, product instructions are clear and understandable, employees are well-trained and keep records, product batches are completely traceable from maker to store and that all complaints are examined carefully.
Nature Made, based in Mission Hills, California produces 150 different kinds of vitamins and supplements each year. All of their products are produced in the United States at modern manufacturing facilities and according to standard GMP guidelines. They also go above and beyond the requirements of law by verifying product quality and ensuring that the proper ingredients are being used with infrared scanning, high performance liquid chromatography and mass spectrophotometry.
Swanson Health Products
Swanson Health Products is a vitamin and supplement company, founded in 1969, based in Fargo, North Dakota. They also operate a new, as of 2010, East Coast Distribution Center in Harrisburg, Pennsylvania. Swanson has operated according to GMP rules since 2001, well before manufacturers were required to follow good manufacturing practices.
MegaFood is a whole food supplement manufacturer in operation for over 35 years. Durham Research and Delta Analytical, their modern manufacturing facility, ensures high-quality product that meets GMP standards with repeated testing and quality control. Each year, their facility is audited by the AIB consolidated standards for food safety. They are also certified by Quality Assurance International as meeting guidelines necessary for producing organic foods.
Puritan's Pride is headquartered in Long Island, New York and manufactures one of the largest lines of supplements, selling 1,000 different types of vitamins, minerals, herbs and other supplements. In operation over 50 years, they utilise ingredients from and sell supplements all over the world. They've worked closely with the FDA and other federal agencies to develop test procedures meeting with GMP guidelines. Daily, hundreds of thousands of orders are filled via a very efficient automated order filling system.