He said he made a plasma donation every two weeks and it felt good to know it helped people in so many ways.
The twins graduated from medical school in November last year and began careers as doctors.
Working as a doctor had brought home how important blood donations were, Kristy said.
She had seen patients who needed one unit of blood and people who needed a dozen.
"Donating blood is one of the most selfless things you can do.
"It comes from you but doesn't cost you anything, and it means so much to the person who receives it, and to their family."
The most common excuse she had heard for not donating blood was a fear of needles.
"I've never met anyone who likes needles. It's just about overcoming that little bit of fear."
Yesterday Mr Toy visited the Tauranga Blood Service to donate some A positive ahead of World Blood Donor Day.
Mr Toy's blood was taken by Pyes Pa registered nurse Karen Wood, who has experienced the other side of the coin - donated blood once saved her life.
Eight years ago she had complications following the birth of her second son and had to have an emergency hysterectomy.
"I was bleeding internally, bleeding out. They had to use quite a lot of blood to keep me going."
She understands she received about 14 units - almost enough to replace her entire body's blood supply.
"I had my doctor tell me many times that I nearly didn't make it.
"When you're giving blood you never think that you'll be the one needing it."
Blood donation by the numbers
80 per cent - Kiwis who will need blood or blood products in their lifetime
Less than 4 per cent - Kiwis that have donated blood in the past two years
3,100 - donations needed every week to meet demand
10 tonnes - plasma donations needed every three months to make plasma products
35 days - how long blood lasts
3 months - time between donations for whole blood donors
2 weeks - time between donations for plasma donors
- Source: New Zealand Blood Service