To Your Health: Minerals
For our bodies to function properly, we need to ingest certain substances from our diets. Among our dietary needs are minerals, the noncarbon elements our body uses for a variety of functions, such developing bone or ensuring proper nerve transmission. The US Department of Agriculture has established some recommendations for the RDIs of various minerals. The accompanying table lists the RDIs for minerals, both in mass and moles, assuming a 2,000-calorie daily diet.
Table \(\PageIndex{1}\): Essential Minerals and their Composition in Humans
Mineral |
Male (age 19–30 y) |
Female (age 19–30 y) |
Ca |
1,000 mg |
0.025 mol |
1,000 mg |
0.025 mol |
Cr |
35 µg |
6.7 × 10−7 mol |
25 µg |
4.8 × 10−7 mol |
Cu |
900 µg |
1.4 × 10−5 mol |
900 µg |
1.4 × 10−5 mol |
F |
4 mg |
2.1 × 10−4 mol |
3 mg |
1.5 × 10−4 mol |
I |
150 µg |
1.2 × 10−6 m ol |
150 µg |
1.2 × 10−6 mol |
Fe |
8 mg |
1.4 × 10−4 mol |
18 mg |
3.2 × 10−4 mol |
K |
3,500 mg |
9.0 × 10−2 mol |
3,500 mg |
9.0 × 10−2 mol |
Mg |
400 mg |
1.6 × 10−2 mol |
310 mg |
1.3 × 10−2 mol |
Mn |
2.3 mg |
4.2 × 10−5 mol |
1.8 mg |
3.3 × 10−5 mol |
Mo |
45 mg |
4.7 × 10−7 mol |
45 mg |
4.7 × 10−7 mol |
Na |
2,400 mg |
1.0 × 10−1 mol |
2,400 mg |
1.0 × 10−1 mol |
P |
700 mg |
2.3 × 10−2 mol |
700 mg |
2.3 × 10−2 mol |
Se |
55 µg |
7.0 × 10−7 mol |
55 µg |
7.0 × 10−7 mol |
Zn |
11 mg |
1.7 × 10−4 mol |
8 mg |
1.2 × 10−4 mol |
Table \(\PageIndex{1}\) illustrates several things. First, the needs of men and women for some minerals are different. The extreme case is for iron; women need over twice as much as men do. In all other cases where there is a different RDI, men need more than women.
Second, the amounts of the various minerals needed on a daily basis vary widely—both on a mass scale and a molar scale. The average person needs 0.1 mol of Na a day, which is about 2.5 g. On the other hand, a person needs only about 25–35 µg of Cr per day, which is under one millionth of a mole. As small as this amount is, a deficiency of chromium in the diet can lead to diabetes-like symptoms or neurological problems, especially in the extremities (hands and feet). For some minerals, the body does not require much to keep itself operating properly.
Although a properly balanced diet will provide all the necessary minerals, some people take dietary supplements. However, too much of a good thing, even minerals, is not good. Exposure to too much chromium, for example, causes a skin irritation, and certain forms of chromium are known to cause cancer (as presented in the movie Erin Brockovich).