Nutrient elements including magnesium, chromium, zinc, copper & selenium are
obligatory co-factors for hundreds of important enzymes & also essential for the
normal functions of vitamins within the body. The levels of these elements in hair
are correlated with levels in organs & other tissues. Toxic elements may be 200-
300 times more highly concentrated in hair than in blood or urine. Therefore, hair
is the tissue of choice for detection of recent exposure to elements such as
arsenic, aluminum, cadmium, lead, antimony and mercury.