Twelve hunger strikers outside a Veterans Administration hospital here have won promises of expanded medical treatment for Vietnam veterans but are still insisting on official White House attention to a broad range of veterans' complaints.

Thom Parish, who served with the Navy in the Tonkin Gulf and is supporting the protestors, said Friday the White House has so far refused to send a representative and so the hunger strike, entering its third week for some of the 12, will continue.

There was indication that the protestors might accept contact with the White House rather than a personal meeting with President Reagan, as they had demanded, and talks between the veterans and a VA attorney were continuing today.

The hunger strikers and a few dozen supporters are camped out in the lobby and in colorful tents on the outside lawn of the huge VA hospital complex in West Los Angeles.

They are asking for more research into the long-range effects of toxic herbicides like Agent Orange, used to remove jungle cover during the Vietnam war, and medical examinations for all veterans who served in Vietnam to identify lingering health problems, particularly the "delayed stress" syndrome.

Two VA officials from Washington told the protesters Wednesday that a team of outside doctors would look into complaints of inadequate care at the VA hospitals here and would investigate the case of ex-Marine James Hopkins, whose apparent suicide May 17 set off the protest. Hopkins drove a jeep through the West Los Angeles hospital's glass doors and fired shots in the lobby two months before his death, blaming his coutbursts on the hospital's failure to treat deafness, which he said was caused by contact with Agent Orange.

"Professionally and personally, we are all concerned about our vets, concerned about Agent Orange, concerned about delayed stress," said Nick Longworth, special assistant to acting VA administrator Donald Custis and one of the officials who spoke to the veterans this week. "we don't want any of those young men to hurt themselves out there."

Longworth also said the VA would expand doctor education and examinations of patients complaining of "delayed stress" syndrome.

Gene Dorr, 34, one of the veterans supporting the protest, said he has been arrested 66 times in the past several years for drunkenness and drug use and is unable to hold a job for more than a few months at a time. he blamed stress associated with his service in the Marine Corps in Vietnam in the mid-'60s.

Chuck Bass, who has been on a diet of fruit juice and vitamins for the last 16 days, said, "I'm going to be here for the duration, until the problem is solved." Bass weighed about 270 pounds at the beginning of the protest and has lost more than 20 pounds. He was briefly hospitalized earlier in the week when he apparently fainted along with another protestor. Both have returned to the protest.