The biologic effects of nutrients and in product-driven articles commonly seen in popular bodybuilding and fitness magazines. However, it is unclear whether these products can be adequately absorbed by the body. Regardless of nutrient effects, if it is not assimilated into the body, any supposed effect will be negated. This is true especially of chromium and is particularly relevant when discussing chromium’s biologic properties for use in physique augmentation as well as its application in medicine.

Two forms of chromium are found in food, inorganic and organic. They have different absorption rates ranging from 0.4-2% and 10-25%, respectively. Data in humans are sparse, with most of the information on absorption coming from animal studies. 179 In this regard, only organically complexed chromium is active. Inorganic chromium entering the general circulation must be changed into the organic form to be used by the body. Chromium appears to be transported in the body bound to transferrin, albumin, globulins, and lipoproteins. Although data are lacking, the liver is hypothesized to be a major site for the synthesis of organic chromium (active) from the inorganic (inactive) form of the mineral. To date, its precise transport mechanism have yet to be clearly defined. Furthermore, no research studies have established how chromium moves from the digestive tract to sites of synthesis or to various storage depots throughout the body. This void in the literature becomes important when discussing oral dosing.

Three chromium supplements are commercially available: chromium picolinate (organic), chromium nicotinate (organic), and chromium chloride (inorganic). Absorption of these three compounds differ, as do their biologic effects. Chromium chloride is believed to be poorly absorbed and not well used by the body, in supplements available to the public, or in laboratory settings.

Chromium picolinate, the most widely used chromium salt, increases receptor-bound and internalized insulin in cultured cells, whereas nicotinate and chloride salts have different actions on the glucose insulin system. These differences indicate a fertile area of research, and future efforts in the laboratory should look into -

a) Establishing how the different forms of chromium act on insulin tissue responsive

b) Defining the exact mechanism by which chromium is processed and transported within the body.

Another important aspect to consider when discussing chromium usage is the pattern of excretion in athletic populations. Exercise increases chromium loss, but as with other physiological adaptations to stress, the form or type of stress (i.e., the mode of exercise) plays a large role in how the body responds. The effects of stress on urinary chromium loss are correlated directly with cortisol. Most of the data collected to date have been reported on aerobic athletes and have shown an increase in unnary excretion after training. Those interested in the effects of aerobic exercise and chromium loss should read the articles by Anderson et al because this chapter will touch on only those studies associated with resistance training.

Currently, not much research has been done on the effects of weight training and chromium excretion. What has been published indicates that those individuals who are involved in high-intensity resistance training may display altered chromium status owing to increased excretion. Despite this finding it is more than likely that these individuals are easily replacing lost chromium because of the typical high-calorie and nutrient-intake patterns associated with these athletes. Also note that a chromium deficiency is unlikely in strength athletes because the majority of these individuals are ingesting supplements (e.g., meal replacements, protein powders, multivitamins/ minerals, and various thermogenic supplements) that contain 200 µg or more of the mineral.

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