ABSTRACT
This chapter describes the essential role the clinical laboratory can play in understanding human nutrition and in evaluating the authors's well-being. It addresses causes of weight change, such as infection and hormonal imbalances. Entrepreneurs from the Massachusetts Institute of Technology established the first stool bank in the United States to provide healthy stool for treatment and research. The chapter explores what role the clinical laboratory plays in evaluating the authors's gut microbiota. The clinical laboratory provides quantitative assessment to guide dosage and assurance that deficiencies and overdoses are avoided. The US Food and Drug Administration (FDA) regulates dietary supplements under a different set of regulations than those covering "conventional" foods and drug products. Although observational studies support a potential role of vitamin D in endocrine disease, high quality evidence from clinical trials does not exist to establish a place for vitamin D supplementation in optimizing endocrine health.
