The Food and Drug Administration, acknowledging that its voluntary approach to regulation has been less than a sparkling success, is considering a mandatory health warning on bone meal products that contain hazardous levels of lead.

Processed bone meal, often sold in the form of powder or tablets, is used as a dietary supplement to bolster the body's supply of calcium. It shares shelf space with vitamins in many health food stores and drugstores.

In June, 1982, the FDA notified 49 manufacturers and distributors of the products that it had found lead in every sample of bone meal it had analyzed, at levels ranging from .04 to 12.8 parts per million.

Lead has been linked to a variety of health problems, including mental retardation and kidney failure, and young children are the most susceptible. The FDA considers levels over 5 parts per million of significant concern.

In its letter to manufacturers, the agency noted that lead "is particularly hazardous for infants, young children and pregnant and lactating women," and recommended that a warning be added to the product's label, saying that bone meal should be consumed by such persons only on the advice of a physician.

According to the Center for Science in the Public Interest, a Washington-based citizens group that requested responses to the letter under the Freedom of Information Act, only three of the manufacturers agreed to add the warning and only one did.

"Roughly 25 didn't respond at all," said Bruce Silverglade, the center's director of legal affairs. "Of the rest, most wrote letters thanking the FDA for its advice, but declining to add the label because it might put them at a competitive disadvantage. Some said that they had a policy of complying with FDA regulations, and to let them know when it becomes a regulation."

The lack of response put the FDA in a bind. Under the Reagan administration, it has adopted a policy of promoting voluntary action rather than regulation. But it also has a longstanding commitment to eliminating lead from the food supply.

Silverglade's organization, which has argued that voluntarism has no place in public health concerns, called the June request a "wasted effort" and "a black eye for regulatory reform."

An FDA spokesman conceded that "only three out of 49 is not a very positive result," but said the main problem was that most of the manufacturers were not analyzing products for lead.

"We want them to test for lead," said agency spokesman Jim Green. "If we find that some manufacturers cannot get to 5 parts per million or lower, then we will probably go with a warning label for those products."

J.B. Cordaro, president of the Council for Responsible Nutrition, an industry association, said the manufacturers believe they can comply with that standard. Both sides are awaiting the results of a new FDA survey, expected to be completed by August.

Meanwhile, Private Formulations Inc. of Edison, N.J., already has added the warning label to its products, with the blessing of its private-label customers, including the 1,800-store Revco drugstore chain.

A spokesman for Private Formulations said it agreed to add the warning "as a protection for infants," even though the firm tests its product for lead and believes it is well within safe limits.

"But nobody really knows, and I don't know why anyone would want to harm a pregnant woman or a little kid," said spokesman Shirley Palchik. "Our customers are very appreciative of any information they get to help them buy a better product. Besides, parents should give children milk, not bone meal."