We recommend that reading the article "A review Hair tissue analysis: An analytical method for determining essential elements, toxic elements, hormones and drug use and abuse", International Journal of Sciences: Basic and Applied Research (IJSBAR) 4:3675-3688 · January 2013.
It describes the elemental hair analysis and its application:
During growth, all nutrients stored in the blood, lymph plasma and other fluids in the organism are stored in the hair. Determining the levels of elements in hair is an ideal method for assessing excesses and deficiencies of elements.
The mineral content in the hair accurately reflects the mineral composition of tissues in the organism. Deficiency or excess of elements in the hair profile usually means deficiency or excess of elements in the body. Minerals are essential during many processes in all phases of metabolism. There are thousands of biochemical reactions that control metabolism, digestion and tissue regeneration. The effectiveness of a large number of these reactions depends on the specific elements. If the amount of essential minerals is insufficient to feed processes in the organism then the ability to regenerate, metabolize or to decompose harmful substances will be compromised. While the parameters in the blood can indicate, what is in the blood at any given time, the hair analysis is a record of how the organism stores and loses elements. The choice of hair as a research material is based on the fact that blood biochemical parameters change from day to day, while hair values give a more stable picture of the overall nutritional status of the hair.
The hair analysis is an invaluable tool for determining the right diet and supplement program for each individual needs. Never before had such an accurate, scientifically justified guide to the functions and metabolic balance in the organism been available. Mineral analysis of hair tissue reflects not only the effects of diet and supplementation on the body but also the effects of other factors on metabolism such as stress, physical activity, endocrine and gastrointestinal functions.
The entire article is available here - READ ARTICLE (CLICK)