Citing a mounting toll of illness and death, federal health officials Thursday expanded their recall of L-tryptophan to include even small amounts of the once-popular food supplement.

To date, the chemical has been linked to 19 deaths and 1,411 cases of a rare blood disorder known as eosinophilia-myalgia syndrome or EMS, the government said."We are confronted with a major public health problem," said Health and Human Services Secretary Louis Sullivan.

Officials said the move was necessary because reports continue to trickle in to public health authorities of illnesses and deaths linked to the product, despite an earlier recall and an order that all imports of the product be detained at U.S. ports.

Mr. Sullivan said the rate of illness had slowed since the November recall, but he feared that some individuals had now resumed taking the food supplement.

The Food and Drug Administration said its previous recall, requested Nov. 17, had applied only to those L-tryptophan products that, when taken as directed, would result in a daily intake of 100 or more milligrams of the chemical.

Thursday's expansion of the recall applied to the product at any dosage, the FDA said.