New Zealand soils are low in selenium, an essential trace element. This results in the vast majority of us being deficient for optimal health. Asthma, prostate cancer and pregnancy failures are three consequences, helped or cured by an adequate level. A fertility centre I contacted said they do not check patients' selenium levels.

Anybody can walk into a Pathlab, pay $45, and get their selenium level measured. It has to be between 1.6~2.0 mcrml/lt. for optimum health.

To correct a low level in two months, take tiny 200mcrgm selenium capsules from iherb.com, or two Brazil nuts/day. Three drops of sodium selenate daily take about seven months to work. It should be the beginning of a lifelong habit for optimal health.

Doctors tell me they weren't trained in trace elements. Many are not au fait with the higher levels that we have only found out within the last 15 years to be so vitally necessary. Dr Gerhard Schrauzer from the University of California in San Diego spoke on the subject at the Auckland Medical School some years ago. He was a worldwide selenium researcher and a great mentor.

D Walpole, Otumoetai.