On January 14, 2009, the Project on Emerging Nanotechnologies (PEN) released a report entitled A Hard Pill To Swallow: Barriers to Effective FDA Regulation of Nanotechnology-Based Dietary Supplements (see attached), which describes problems at the Food and Drug Administration (FDA) in regulating nano-enabled dietary supplements and offers recommendations for improving oversight.
See http://www.nanotechproject.org/publications/archive/pen17/