Toxicity   The metabolism of amygdalin produces hydrogen cyanide, a potent toxin. Beta-glucosidase, one of the enzymes that catalyzes the  release of cyanide from amygdalin, is present in the human small  intestine and in a variety of common foods. This leads to an unpredictable and potentially lethal toxicity when amygdalin or laetrile is taken orally. Ingestion of purified amygdalin or apricot seeds can cause severe toxicity and death due to cyanide poisoning. Numerous case reports in medical literature describe serious cyanide poisoning in patients who ingested laetrile as a cancer treatment.