The teaser for the 2018 documentary film “Vitamania,” about the history of supplements, recounts a disastrous 1913 Antarctic trek.

The last two remaining explorers, Douglas Mawson and Xavier Mertz, had to slaughter their Huskies for food. Later, they became progressively ill, with drying and fissuring of the skin and, for Mertz, madness and death.

There's speculation that eating the dogs' livers, which are packed with vitamin A, gave the adventurers a condition called hypervitaminosis A.

These days, hypervitaminosis A mostly happens when someone takes too much vitamin A for too long. But that's just one of the hazards of taking supplements.

For example, according to the National Institutes of Health, “products labeled as kava have been linked to the development of ... acute liver injury, which can be severe and even fatal.”

Supplements aren't regulated by the Food and Drug Administration, which is only able to issue alerts and recalls after dangerous products appear on the market.

But the agency recently announced that it would explore improving communication about harmful ingredients and reform regulatory guidelines that ensure product safety.

For now, look for a seal from U.S. Pharmacopeia, NSF International, or ConsumerLab.com certifying that a supplement isn't contaminated and the contents are verified.

Discuss all supplements with your doctor, so that you don't have negative interactions with other supplements or medications you're taking.