- IRONZ Welcome to the New Zealand Haemochromatosis Support & Awareness Group (IRONZ) website. What is Haemochromatosis Haemochromatosis is a disorder of iron regulation (metabolism) in your body. Because the regulation of iron absorption is out of kilter , excess iron is stored in the tissue. The abnormal regulation of iron absorption is believed to occur in the gut. Iron accumulates over a long ...www.ironz.org.nz