[tansika (OP)]

Minor chemical newbielink:http://bodyparticles.com/composition-table.php [nonactive] and its percentage.

Lithium (Li)-0.0000031%
Beryllium (Be) -0.000000005 %
Boron (B) -0.000069 %
Fluorine (F) 0.0037%
Sodium (Na) -0.15 %
Magnesium (Mg) -0.05%
Aluminum (Al) - 0.000087%
Silicon (Si) - 0.002%
Sulfur (S) - 0.25%
Chlorine (Cl) - 0.15%
Potassium (K) - 0.35%
Titanium (Ti) - 0.000013%
Iron    (Fe) - 0.006%
Cobalt (Co) - 0.0000021%

[CliffordK]

Interesting list of elements. 

That doesn't mean that the existence of an element in the body indicates that it is a vital mineral, or that it has any positive physiological function.

So, according to your link, one also finds the following elements:

Arsenic (As) 0.000026%
Radium (Ra) 0.00000000000000001%
Uranium (U) 0.00000013%

And, it is quite likely that smokers would also have a measurable amount of Polonium-210 (Po) in their bodies.

With the Arsenic, Radium, Uranium, and Polonium all being toxic and quite possibly carcinogens, even at low concentrations.

[evan_au]

It is thought that about 2 dozen elements are essential for human life - see http://en.wikipedia.org/wiki/Dietary_mineral#Essential_chemical_elements_for_mammals

When it comes to really common elements like silicon which are everywhere, but needed in very low concentrations, it becomes very hard to prove whether they are needed or not.

But if you have a balanced diet, you will get enough of the essential elements, so you don't need to buy fancy trace elements. Generally, where dietary intake is inadequate (eg goiter in mountainous regions due to lack of iodine), this is now recognised by medical authorities, and corrected by supplementing the food supply (like iodine in salt).