there exists a group of physicians practicing "functional medicine" who order testing to determine if one is deficient in vitamins and minerals, as well as whether pathways for utilizing vitamins and minerals are functional. I found out I do not absorb Folic acid, and must use one of the metabolized products of this vitamin. the testing also rated one's "antioxidant level"--to assist in dietary planning. there is a web site for this group: Institute of Functional Medicine
(practitioners are MD's--there is much emphasis on biochemical aspects)

http://www.functionalmedicine.org/about/whatis.asp
What is Functional Medicine?
Functional medicine is a science-based field of health care that is grounded in the following principles:

Biochemical individuality describes the importance of individual variations in metabolic function that derive from genetic and environmental differences among individuals.

Patient-centered medicine emphasizes "patient care" rather than "disease care," following Sir William Osler’s admonition that "It is more important to know what patient has the disease than to know what disease the patient has."

Dynamic balance of internal and external factors.

Web-like interconnections of physiological factors – an abundance of research now supports the view that the human body functions as an orchestrated network of interconnected systems, rather than individual systems functioning autonomously and without effect on each other. For example, we now know that immunological dysfunctions can promote cardiovascular disease, that dietary imbalances can cause hormonal disturbances, and that environmental exposures can precipitate neurologic syndromes such as Parkinson’s disease.

Health as a positive vitality – not merely the absence of disease.

Promotion of organ reserve as the means to enhance health span.
Functional medicine is anchored by an examination of the core clinical imbalances that underlie various disease conditions. Those imbalances arise as environmental inputs such as diet, nutrients (including air and water), exercise, and trauma are processed by one’s body, mind, and spirit through a unique set of genetic predispositions, attitudes, and beliefs. The fundamental physiological processes include communication, both outside and inside the cell; bioenergetics, or the transformation of food into energy; replication, repair, and maintenance of structural integrity, from the cellular to the whole body level; elimination of waste; protection and defense; and transport and circulation. The core clinical imbalances that arise from malfunctions within this complex system include:

Hormonal and neurotransmitter imbalances

Oxidation-reduction imbalances and mitochondropathy

Detoxification and biotransformational imbalances

Immune imbalances

Inflammatory imbalances

Digestive, absorptive, and microbiological imbalances

Structural imbalances from cellular membrane function to the musculoskeletal system
Imbalances such as these are the precursors to the signs and symptoms by which we detect and label (diagnose) organ system disease. Improving balance – in the patient’s environmental inputs and in the body’s fundamental physiological processes – is the precursor to restoring health and it involves much more than treating the symptoms. Functional medicine is dedicated to improving the management of complex, chronic disease by intervening at multiple levels to address these core clinical imbalances and to restore each patient’s functionality and health. Functional medicine is not a unique and separate body of knowledge. It is grounded in scientific principles and information widely available in medicine today, combining research from various disciplines into highly detailed yet clinically relevant models of disease pathogenesis and effective clinical management.

Functional medicine emphasizes a definable and teachable process of integrating multiple knowledge bases within a pragmatic intellectual matrix that focuses on functionality at many levels, rather than a single treatment for a single diagnosis. Functional medicine uses the patient’s story as a key tool for integrating diagnosis, signs and symptoms, and evidence of clinical imbalances into a comprehensive approach to improve both the patient’s environmental inputs and his or her physiological function. It is a clinician’s discipline, and it directly addresses the need to transform the practice of primary care.