Two blood transfusions gave her back her life. Yesterday, Lana Coc-Kroft was saving someone else's life in return, lending her support to the Blood Service as it marked World Blood Donor Day.

Coc-Kroft had been given the all-clear to give blood again after her life-and-death battle with a rare virus last year. Contracted from a coral cut while filming Celebrity Treasure Island in Fiji, the virus left the mother of two in a coma for nine days.

The Blood Service hopes Coc-Kroft's personal tale will help to halt falling donor numbers.

Last year, the service attracted 23,000 new donors, but also lost 28,000 donors.

Coc-Kroft, who was a donor for 20 years before her illness, said it was a simple gift that could ease a lot of suffering.

"It's just like sponsoring a child. It's that simple. It's amazing what one little litre or two litres of blood can do.

"If you've got someone in the hospital in need of blood, the last thing you want to have to do is wait."

Chief executive Graeme Benny said the Blood Service generally had just enough blood stocks to meet demand, but the situation was becoming more difficult as the number of regular donors fell.

Blood's short shelf life compounds the problem. Red blood must be used within 35 days of collection and platelets, which are separated from red blood cells and plasma, last only five days.

Dr Benny said the service needed 30,000 new donors each year just to meet demand.

In Auckland, the service needs to gather 220 units of blood a day.

Only 5 per cent of New Zealand adults donate blood, but 80 per cent will need blood or blood products at some stage.

Who can donate:

* People in good health between 16 and 60 (existing donors can give blood up to the age of 70).
* People who have had no body piercing or tattoos in the past six months.
* People who did not live in Britain between 1980 and 1996 for more than six months.
* People who have not visited the African region or South America recently.
* Become a donor by calling 0800 GIVE BLOOD (448-325) or visiting the website (link below)