When it comes to studying nutrition, this sort of extensive, long-term clinical trial is supposed to be the gold standard.

"But we need long-term, large-scale prospective trials to actually prove that."

"It is premature to initiate a long-term trial until data from our current trials are completed and analyzed," an Army spokesman said.

But long-term trials have yet to be completed.

The next step is long-term trials that look at the effects of vitamin D supplementation in people with asthma, the study authors say.

The law demands no ongoing long-term clinical trials to establish either the safety or efficacy of these supplements.

To better understand the potential role chromium may play in the treatment of type II diabetes, long-term trials need to be conducted for the future.

A long-term trial of hydroxyurea to treat the disease began at six medical centers last year.

He didn't know, hadn't done the proper long-term trials, was in too big a rush.

No long-term human clinical trials have been conducted.