King-Dye, 32, remains in a coma following a fall during a training session at her farm in Loxahatchee, Florida.
Blitz said at the weekend that risks are inherent in equestrian sport, but "it's a calculated risk that we accept but one where we should take every precaution to promote safe practices."
She said trainers advocate the use of a helmet, yet often riders at home and in competition are seen without any protection. "It has long been a policy of mine that students must wear a helmet. This is a reminder and a rallying call to my colleagues around the world to do the right thing.
"The terrible accident to our colleague and friend, Courtney King-Dye, is a harsh reality check of what can go wrong, in a simple schooling situation at home, on the flat, with no fences or obstacles in our path. Falls do not just happen in eventing or jumping - they happen in dressage too.
"Horses are horses and we cannot control their every movement, no matter how experienced the rider. We can, however, take responsibility for our own safety by wearing a helmet in all circumstances when we are mounted," Blitz said.
At last week's Palm Beach Derby in Florida, Jacquie Brooks rode both her Grand Prix tests with a crash helmet instead of her top hat.
• Last year, Florida passed a law making riding helmets compulsory for children under 16 riding in public areas. House Bill 169, is known as "Nicole's Law", after Nicole Hornstein, a 12-year-old girl from Loxahatchee who died after being thrown from a horse in June 2006.