Vitamin B17: Food Sources and Why You Should Avoid It

Have you been getting enough vitamin B17 in your diet? Well, chances are you haven't — and for good reason.

"For starters, vitamin B17 is not even considered a vitamin in the peer-reviewed scientific literature," Julie Upton, RD, co-founder of Appetite for Health, tells LIVESTRONG.com. "B17 is a naturally occurring compound known as amygdalin," she says.

Also referred to as laetrile, Upton adds that it can be found in the pits of some fruits, most notably:

• apricots
• apples
• plums
• cherries
• peaches
• raw nuts (such as bitter almond)
• lima beans
• sorghum

"Since it is not considered essential, B17 does not have a Recommended Dietary Allowance (RDA) associated with it," Upton says.

B17 or amygdalin was initially discovered by French chemists back in 1830. About 15 years later, it was used in Russia as a treatment for cancer, according to case studies in the August 2017 issue of ​Case Reports in Emergency Medicine​.

The United States took notice and began using this compound as an alternative cancer therapy during the 1920s. Then, it was converted into a purified form and distributed as laetrile in the 1950s, even though the Food and Drug Administration (FDA) considered it an unapproved new drug.

But in 1977, a U.S. District Judge in Oklahoma granted permission of the substance to treat people with terminal cancer. The National Cancer Institute conducted two clinical trials, yet they failed to uncover any evidence to support this claim. In the mid-1980s, the FDA banned the sale of amygdalin/laetrile.

"So while amygdalin has been shown to have some anti-cancer, immune-boosting, blood pressure lowering and pain relieving benefits, studies are preliminary and more research is necessary," Upton says.

"What's more, there may be potential toxicity related to the compound."

Amygdalin can be broken down in the system with the help of enzymes and turned into cyanide — yes, poison, as explained by the Memorial Sloan Kettering Cancer Center.

Those who were in favor of this substance as an alternative cancer treatment stated that the cyanide targets cancer cells while leaving the healthy cells intact. Yet the clinical research did not prove this theory. In fact, scientists found that some people with cancer who were given B17 tested for cyanide toxicity.

Other possible side effects from amygdalin/laetrile include inflammation of the skin, nausea, vomiting, headaches, dizziness, low blood pressure, coma and death.

Amygdalin or laetrile — which can be labeled as vitamin B17 (although it is not a verified vitamin) and come in the form of a pill or an intravenous injection — is not approved by the FDA due to possible cyanide poisoning.

While it is available on the market (the National Cancer Institute states that laetrile treatments are offered in Mexico and in some clinics around the U.S.), this bitter substance that derives from the pits of some plants and fruits is not regulated and could lead to life-threatening side effects.