Driven by Curious Data

Teddy Tucker and the Big Headache: - Vitamin A Intoxication from Reef Fish Livers

When our team came together to work in Bermuda back in 2003 we were lucky enough to partner on many projects with locally and internationally famous “man of the sea” Mr Teddy Tucker. In our many conversations while out on the water Teddy made reference to an event that continued to baffle him. When Teddy first came back to Bermuda after the War he spent a great deal of his time fishing. Bermuda had plenty of fish in those days and fishing far off shore was not worth the effort. Teddy, driven by a desire for new experiences and being someone who did things his own way would occasionally make his way out to the outer sea mounts to the west of Bermuda, Challenger and Argus Banks. Some time in the late 1950’s after consuming fish livers from grouper he fell curiously and horribly ill, groupers caught at Challenger Banks.

The Story always went like this “It starts with the worst headache you will ever have in your life. Like someone is squeezing a vice around your head” “This lasts a full day but that's just the beginning” and then Teddy lists acataclysm of symptoms that start with the headache and then progresses through loss of the upper layer of skin on your scalp, the palms of your hands and the bottom of your feet, literallypeeling off in large sheets ( “I couldn’t put my feet on the ground for days they were so sensitive”) and ending with losing all your fingernails. A process he told us he fully recovered from some 6 months after it began.

This horrendous ordeal was however, predictable and avoidable. Teddy had been warned by old-time fishermen not to eat Banks livers – fish livers from Challenger Banks. Thirty years later, as he returned with friends from a successful fishing day at Challenger Banks with a big grouper in the boat and a nice fat liver in the bucket, Teddy would pass on this same warning.

Teddy said  "I was getting ready to throw it overboard (the liver) when Robert said to me, 'What are you doing, that’s mine! I’m going to eat it tonight with some fried onions.' I told him 'Robert, you don’t want to eat Rockfish livers from the Banks'. He didn’t believe me." Teddy and his friends were known to enjoy practical jokes and Robert, assuming it was a clumsy attempt to cheat him out of a nice fish liver dinner, dismissed the warning. As he walked off the boat Teddy told him, “you’ll regret it”.

That evening Robert called Teddy gloating to tell him, as he was eating it how good the liver was.  Several hours later Robert’s wife Hazel called back to say, “Robert told me to call you; he’s lying on the floor with his head in the freezer. What can he do?" Teddy said, “Tell him that's just the beginning”.

To Robert's wife’s despair, the following weeks brought the same reign of misery that Teddy had experienced decades before, but in this instance Robert  also suffered from a loss of pigment on his face and arms which forced him to wear a legionnaire's hat and long sleeved shirts whenever he ventured into the sun for the rest of his life.

Through Teddy we met two other people who, either ignorant of the folk wisdom of the old timers or unconcerned by the warnings, had suffered to various degrees the affliction of consuming Banks livers. We also spoke to one of their GPs who had been dumbfounded at the unique and varied array of symptoms presented by his patient.

The story remained in our roster of curious data until we had a chance to sample a large number of fish and fish livers as a part of a research program designed to assess levels of Mercury, Selenium and Omega 3 in Bermuda fish in order to create a fish advisory for pregnant women.  With over 300 fish samples in our possession – many of which came from the Banks we were suddenly faced with the question “what do we test the livers for?"

Testing is not what one immediately thinks. There is not an all-encompassing, perfect testing machine into which you place your sample and from which you extract all there is to know about what is good and what is offensive. One needs to have a starting point, some hypothesis, some indication of what to look for.

We, therefore, gathered together all the symptoms, described the individual cases from a clinical point of view and then left it to sit in the back of our minds for many months occasionally drawing upon this medical mystery to entertain in dinner conversation, or to test a relevant audience.

Sitting around a table in 2008, Teddy, Eric and I began once again describing this curious data to Dr. Ed Shultz the chief of emergency medicine and wound care at the Bermuda Hospital and a good friend of Teddy’s. During the discussion Dr. Shultz  recalled reading about something similar among the early arctic explorers.

Eric and Ed then recalled that this had been discovered to be caused by the consumption of polar bear livers – the root cause being a surplus of Vitamin A. Polar bear livers, in fact, contain incredibly high concentrations of Vitamin A. Vitamin A performs many important functions in the human body from vision to immune function and is a critical vitamin in embryonic development, but as a fat soluble vitamin, however, the body can not get rid of it easily, and dietary surpluses can accumulate and cause a range of effects – from yellowing of skin, massive headaches right through to skin desquamation with symptoms adding one on top of the other in layers.  Could Vitamin A be the root cause of Teddy and Robert's symptoms? Could fish livers from the middle of the semi-tropical Atlantic be as high in Vitamin A as polar bear livers? 

We tested the fish livers that we had collected and found that for some the levels of Vitamin A were incredibly concentrated: a 70 g taste of chub liver contained 500,000 IU of Vitamin A,  166 times the recommended daily allowance and over 50 times the dosage for first intoxication. These levels of Vitamin A mean that even just 2 grams of liver consumed could be expected to cause some version of symptomatic hypervitaminosis A, the same debilitating symptoms described for Arctic explorers eating polar bear livers. If an entire fish liver with the extreme levels of Vitamin A we noted were consumed, as was the case with Teddy and friends, the exposure would be catastrophic.

This, however, only answered half the question for Teddy. His ultimate question was the assertion by the elders - that only the livers of grouper on Challenger Banks were affected.

The samples we collected were part of another study and while we could test for Vitamin A we could not compare between locations. We had discovered the cause, but to Teddy's frustration we could not test this premise.

Teddy was deeply intrigued as to what difference might exist between the two seamounts separated by only 3 miles of deep water. What could account for such a profound difference? Differences in fish and fish feeding behavior between the Bermuda Sea Mount and Challenger Banks? Differences in particular foods? We continue to be intrigued by this possible disparity and when the opportunity presents itself we will compare banks livers vs Bermuda seamount livers in the same rockfish species at the same season and same size.

There also remains for us a basic question regarding fish physiology or feeding behavior that we would also like to know that could help answer Teddy’s conundrum. Why and how do some fish accumulate such concentrated doses of the Vitamin A? 

In addition we need to take into account other fishermen’s assertions from traditional lore that posit that the risks of eating fish liver are related to the consumption of what in Bermuda are called “floating fish“ (pelagic – not bottom fish).

Regardless of either theory the idea that Vitamin A concentration in fish livers is localized, either to place or species, remains a mystery.



The research once peer reviewed and published immediately added a new dimension to other curious data from fishing communities. In Barbados where Atlantis and OHH carried out two years of work, some of it with local pelagic fishermen“the big headache” has in folklore been attributed to the consumption of marlin liver – a part of the fish eaten to make the blood strong. The ensuing headache was expected and seen as a testament to the power of the liver to enrich the blood. “The headache means its working, making your blood strong!” It is likely to be a result of too much Vitamin A.

We also learned that an extreme case of hypervitaminosis A might lead to actual depigmentation.

The most significant effect might be in the reinterpretation of previous cases of fish consumption related sickness. Some hospital visits related to fish consumption had been ascribed clinically to Ciguatera exposure. The description of hypervitaminosis A from fish liver consumption and associated symptoms demonstrated the possibility of confounding diagnoses through symptoms noted. Some cases previously ascribed as being caused by Ciguatera poisoning can now instead be definitively attributed to hypervitaminosis A.  Today any doctor who consults the literature when presented with an illness that might be associated to fish consumption can now diagnose specifically for hypervitaminosis A.

Not a bad result for a study that started with a fishing story.

Philippe Max Rouja PhD