Hi Wen. 

Had some iron issues.  Also, decades ago around the time when I started losing my health had braces (nickel) on my teeth for a very long time.   

Here are some good quotes

Just by the very act of harboring other creatures in us, we become a repository of all their metals. The harm that is done by nickel alone, besides inviting infection, is major. It consumes our iridium and it turns us southerly! Iridium levels fall very low wherever nickel deposits are seen. A tumor, due to its stockpile of nickel from Clostridium bacteria, cannot salvage its own iron deposits and make it usable again. There is an iridium shortage. Yet, the iron ferrite (Fe₂O₃  deposits must be cleared away somehow to get the tumor zone back to a northerly polarization.

Nickel turns us southerly. 

Healing cannot go forward because of low iridium levels. A very low level of 29 is reached for iridium (in homeopathic units of 1 in 5 dilution) in advanced cancer. Levels in the 80’s are normal, and a level of 120 is seen in young children.

http://www.drclark.net/en/cleanses_clean-ups/toxins_chelation/metals.php