Shortfall of 7,500 in blood donor study

More than 7,500 donors are needed to take part in new research to determine how often people can safely give blood.

In the UK, donors can give every four months but in France and Canada, the interval is shorter - every two months.

NHS Blood and Transplant (NHSBT) is carrying out the research with 42,500 donors over the next two years.

Donor centres taking part include Manchester.

The aim of the interval study is to determine whether the length of time between blood donations can be tailored to suit people's age, weight, diet and inherited factors without depleting iron levels.

During the study men are allocated eight, 10 or 12 week blood donation intervals and women randomly allocated to 12, 14 and 16-week intervals.

A spokesman for NHSBT said: "In Canada and the US, the interval is eight weeks for everyone, in France it's up to six times per year for men and four times for women.

"In Australia it's once every 12 weeks for everyone - so it's a very mixed picture - some countries err on the side of caution and impose intervals which are designed to be safe for everyone.

"The interval study will hopefully be able to set bespoke interval periods for different people, depending on certain characteristics - this is why it is so groundbreaking."