ABSTRACT
I. Introduction................................................................................. 341 A. Dietary Intake ........................................................................ 341 B. Blood Biochemical Measures ................................................ 342
1. Sample Collection............................................................. 342 2. Sample Contamination..................................................... 342 3. Analytical Methods .......................................................... 343 4. Quality Control................................................................. 343
II. Calcium........................................................................................ 344 A. Methods for Assessing Calcium Status ............................... 344
1. Total Serum Calcium........................................................ 344 2. Serum Ionized Calcium ................................................... 344 3. Calcium Reference Intervals and Data from
Interventions in Physical Activity .................................. 345 III. Chromium.................................................................................... 345
A. Method for Assessment of Chromium Status ..................... 346 1. Reference Intervals and Data from Physically
Active Persons .................................................................. 346 IV. Copper ......................................................................................... 347
A. Methods for Copper Assessment ......................................... 347 1. Serum or Plasma Copper Concentration........................ 347 2. Ceruloplasmin .................................................................. 348 3. Superoxide Dismutase Activity....................................... 348
a. Erythrocyte Superoxide Dismutase ............................ 348 b. Extracellular Superoxide Dismutase .......................... 349
4. Cytochrome C Oxidase Activity ..................................... 349 5. Copper Reference Intervals and Data
from Athletes .................................................................... 349 V. Iron............................................................................................... 350
A. Methods for Assessment of Iron Status............................... 351 1. Hemoglobin and Hematocrit ........................................... 351 2. Ferritin .............................................................................. 351 3. Serum Iron, Total Iron-Binding Capacity,
Transferrin and Transferrin Saturation........................... 352 4. Transferrin Receptor ........................................................ 352 5. Free Erythrocyte Protoporphyrin and
Zinc Protoporphyrin ........................................................ 353 6. Iron Reference Intervals and Data from Athletes
and Physically Active Persons ........................................ 353 VI. Magnesium .................................................................................. 353
A. Methods for Assessment of Magnesium Status .................. 355 1. Serum or Plasma Magnesium Concentration................. 355 2. Ionized Magnesium Concentration................................. 355 3. Magnesium Concentration in Muscle ............................. 355 4. Magnesium Content of Blood Cells ................................ 356 5. Magnesium Retention after Acute Administration ....... 356 6. Magnesium Reference Intervals and Data
from Athletes and Physically Active Persons ................ 356 VII. Phosphorus .................................................................................. 357
A. Methods for Assessment of Phosphorus Status.................. 358 1. Phosphorus Reference Intervals and Data from
Phosphate Supplementation Trials ................................. 358 VII. Zinc .............................................................................................. 358
A. Methods for Assessment of Zinc Status .............................. 359 1. Plasma or Serum Zinc...................................................... 359 2. Zinc-containing Enzyme Activities ................................. 359 3. Zinc Reference Intervals and Data from Athletes ......... 360
IX. Other Minerals ............................................................................ 360 A. Manganese ............................................................................. 361
1. Methods for Assessment of Manganese Status.............. 361 2. Manganese Reference Intervals ..................................... 362
B. Selenium................................................................................. 362 1. Methods for Assessment of Selenium Status ................. 362 2. Selenium Reference Intervals .......................................... 363
X. Summary and Conclusions ........................................................ 363 References ............................................................................................. 363
As knowledge of the biological roles that mineral elements play in the development and maintenance of physical fitness and performance grows, there is burgeoning need for tools to assess the adequacy of mineral element nutritional status of physically active persons. Pursuit of the appropriate assessment tool is complicated by theoretical and practical limitations. The ideal method is specific and sensitive; it distinguishes adequate from deficient nutritional status and discriminates graded degrees of nutritional deficiency. The method also is practical, convenient and noninvasive, reflects cellular mineral element content and adequacy of function and responds proportionally to changes in dietary intake. Unfortunately, no single method achieves all of these criteria. Thus, a compromise among available approaches is needed to accommodate the requirements of a valid and practical method to routinely assess human mineral nutritional status.
