If you are strictly a retailer, the exemption in section 111.1 Paragraph b applies. It appears that both questioners are holding or warehousing product. In this case, each company as a holder of dietary supplements would be subject to the regulations of 21 CFR Part 111 as is anyone if they “manufacture, package, label, or hold a dietary supplement.” As a holder of supplements, all regulations apply, but specific sections of the regulations that you should be familiar with include sections 111.453–111.475 Holding & Distributing.

Vibrant Health, you mentioned that you also purchase the ingredients that are then contract manufactured into the dosage products. The ingredients themselves require special handling and testing requirements, some of which are outlined in sections 111.153–111.180. Ingredients, at a minimum, need to be tested for identity. In addition, a supplier qualification program for these ingredients must be maintained. Keep in mind that a small company, defined as having fewer than 20 employees, has until June 25, 2010, to comply with the regulations.

Two great resources for understanding the regulations and helping you with compliance are DBA and NSF.