Newfoundland and Labrador's largest health authority said Monday it won't do any more general testing for vitamin D because its lab is being overwhelmed.

In the last two years, Eastern Health authority has seen a 10-fold increase in people wanting to be tested for vitamin D deficiency. The request for tests has steadily climbed since July 2007, and peaked in January at 5,000 tests a month.

Scientific studies have suggested vitamin D, also known as the sunshine vitamin, could protect against a number of illnesses including cancer and depression.

Eastern Health's laboratory medicine director Lynn Wade said at $25 per test, it was costing a fortune to tell people that everyone in the province who isn't taking a vitamin D supplement should be taking one.

"It was just unsustainable here in our lab. It was costing us approximately $500,000 … over the course of the last year," she said.

"Aside from the cost of it, it was also backlogging our workload. We just were not able to sustain that level of testing."

Eastern Health has provided education for physicians to help them decide when they should be ordering vitamin D testing.

The test is still available for anyone who requires it due to a predetermined condition.