Federal and state investigators said they are looking into what role vitamin E might be playing in mysterious lung illnesses affecting some people who use cannabis vaping products.
The New York Department of Health said Thursday that vape products containing vitamin E have been linked to every patient who has submitted a product for testing to state health officials.
While nearly all cannabis vaping products tested positive for vitamin E, none of the nicotine-based products contained the chemical, New York officials said.
"As a result, vitamin E acetate is now a key focus of the Department's investigation of potential causes of vaping-associated pulmonary illnesses," the department said.
Vitamin E is not known to cause harm when ingested in a pill form as a vitamin supplement, but investigators said there could be dangers associated with inhaling it due to its "oil-like" properties.
Sick patients have reported a cough, shortness of break, chest pain, as well as nausea, vomiting, diarrhea, fatigue, fever and weight loss.
The Washington Post reported Thursday that the Food and Drug Administration has also identified vitamin E in cannabis products in samples taken from patients who have become ill.
As of Aug. 27, 215 possible cases of pulmonary disease associated with vaping, including two deaths, have been reported to the U.S. Centers for Disease Control and Prevention.
New York officials said they have received 34 reports from state doctors of severe pulmonary illness among patients who have used at least one cannabis vape product before becoming sick.
"The cases of pulmonary illnesses associated with vaping are continuing to rise across New York State and the country," said New York Health Commissioner Howard Zucker.
"We urge the public to be vigilant about any vaping products that they or any family members may be using and to immediately contact their health care provider if they develop any unusual symptoms. In general, vaping of unknown substances is dangerous, and we continue to explore all options to combat this public health issue."
State officials didn't identify one particular brand linked to the illness, noting that all patients have reported recent use of various products.
Many of the products tested are suspected to be counterfeits of others that contain cannabis and which are available in other states, officials said.
Recreational cannabis vape products are illegal in New York.
"Anyone using vape products should never use unregulated products purchased 'off the street,'" the New York State Department of Health said in a statement.