THE FOLLOWING ARTICLE APPEARED IN THE

OCTOBER 1999 ISSUE

THE POISON SLEUTHS

DEATH BY VITAMIN A

-Dr. Anil Aggrawal

"Good morning doctor. Oh, my God, what are you doing today? You have the dead body of a young man today. What happened to him? Please tell me.”

“Good morning Tarun. The name of this 24 year old man is Ramlal, and he died in the hospital today morning. He was admitted to the hospital about two days back, with complaints of throbbing headache, pain in the stomach, diarrhoea, vomiting, irritability, dizziness, muscular weakness and cramps. Some peculiar symptoms, which confused most doctors at the hospital was that his skin was peeling off from many parts of the body, his hair were falling and that he had an irresistible desire to sleep. Doctors were trying to figure out what his illness was, but in the meantime he expired.”

“Seems like a most strange illness to me doctor. But since you have said that his hair were falling, I can surmise that he might be suffering from Thallium poisoning.”

“Tarun, I do remember having told you that hair start falling in thallium poisoning, but look at his other symptoms too. All the symptoms taken together are pointing towards only one direction - I can think of nothing but one poison, with which Ramlal must have been poisoned. It remains to be seen who gave him this poison.”

“Doctor please tell me which is that poison. I am getting curious.”

“Tarun, somebody has given Ramlal a dangerously high dose of Vitamin A, and probably that is why he has died.”

“Vitamin A! Come on doctor. You are being preposterous. We all know that Vitamin A is an essential vitamin, which must be regularly taken to stay healthy. How can such a nutrient prove toxic?”

“This is the paradox. Vitamin A acts as a double edged sword. Before saying anything, let me clarify a few basic concepts about Vitamin A. The term “Vitamin A” covers two chemicals - a true pre-formed vitamin known as retinol, and a pro-vitamin beta-carotene. A pro-vitamin is a substance which gets converted into the proper vitamin in the body. In human beings, some beta-carotene gets converted into Vitamin A in the intestinal mucosa, while the most gets converted in the liver. Vitamin A is usually measured in International Units or I.U. One I.U. of Vitamin A is equal to about 0.3 micrograms of retinol, which as you now know is the true Vitamin A. I must also tell you that one microgram of beta-carotene (which is the pro-vitamin) gets converted to about 0.167 micrograms of true vitamin A or retinol. Another way of saying this is that the “retinol equivalent” of one microgram of beta-carotene is 0.167.”

“Oh, yes, I am understanding it. What is the daily requirement of Vitamin A, and what is its toxic dose?”

“Normal daily requirement of Vitamin A for an adult is about 3000 I.U. per day. In pregnancy and lactation, it increases to about 4000 I.U. per day. Vitamin A capsules available in the market provide a little more than this amount. For instance Adexolin, a commonly available capsule of Vitamin A contains about 5000 I.U. of vitamin A. You must remember that Vitamin A and D are not soluble in water so if someone takes more quantities of these vitamins than required, there is no way they can be excreted. They generally are stored in the liver. On the other hand Vitamins B and C are water soluble vitamins. If someone takes enormous quantities of Vitamin B and C, they would be excreted in urine.”

“Oh, I see. So this means Vitamin A can act as a poison too?”

“Oh yes. Certainly. This is a fact which most people do not know. The medical condition which results from an intake of excessive amounts of Vitamin A is known as Hypervitaminosis A. About one million I.U. of vitamin A are very toxic to human beings, and about 3 million I.U. may prove fatal, as they have in the case of Ramlal. To put it another way, about a year’s requirement of Vitamin A if taken as a single dose may prove toxic, and about three years’ requirement taken as a single dose may kill a human being. Well, we do say often that ‘too much of a good thing can be bad’. Nowhere does this maxim prove truer than in the case of Vitamin A.”

“Doctor, you are repeatedly saying that Ramlal died of Vitamin A poisoning, but how could he have got poisoned. You tell me that an average capsule of Vitamin A available in the market provides about 5000 I.U. of vitamin A, and also that about 3 million I.U. are fatal. This means that someone with an intent to kill his enemy has to administer as many as 600 capsules of Vitamin A to his enemy. How is that possible?”

“Tarun, I did not tell you a very interesting fact. Most polar animals such as polar bears have dangerously high levels of Vitamin A in their liver. In fact there have been cases, where polar explorers have died of Vitamin A poisoning, because they ate the livers of animals residing in those regions.”

“Really? That’s an interesting fact. How does such dangerous amounts of Vitamin A reach their liver?”

“Vitamin A originates in marine algae, and then passes up the food chain to reach the large carnivorous animals. Toxic levels of Vitamin A may accumulate in the livers of a wide range of creatures such as Polar bears, seals, porpoises, dolphins, sharks, whales, Arctic foxes and huskies.

Even a small meal of southern Australian seal liver, say 80 g, may produce illness in man. I may tell you that several foods are recommended as good sources of Vitamin A. Most of them contain well below the toxic levels of vitamin A, but one - Halibut liver oil - contains dangerously high amounts of Vitamin A, as you can see from the accompanying table.

Table 1: Vitamin A content of some commonly recommended foods rich in Vitamin A

In contrast look at the vitamin A contents of the livers of some common animals living in the polar regions in the following table. For comparison, I have also given the vitamin A content of the human liver. As you can see, most animals, especially the polar bear have very high amounts of Vitamin A in their livers.

Table 2: Vitamin A content of the livers of some common animals living in polar regions - compared with that in humans

“Oh, these two tables are real eye openers. Doctor, you were telling me that some polar explorers have actually died of Vitamin A poisoning. Could you tell me that story in detail please? I am getting curious.”

“Oh sure. The story starts in January 1912, when a three man party of explorers from the Australasian Antarctic Expedition started their expedition to explore Antarctica. The team was led by Douglas Mawson, and the other two members were Lt. B.E.S. Ninnis and Xavier Mertz, a Swiss scientist. Disaster struck on December 14, 1912, when Ninnis fell into a very deep pit and died. With him also went precious food supplies. With most of their food gone, Mawson and Mertz decided to return to their base at Commonwealth Bay, which is at the shores of Antarctica. From here they could take the ship back to their country. But Commonwealth Bay was about 315 miles from where they were stationed. Covering that distance in the inhospitable surroundings of Antarctica would have taken them weeks, and they had only 10 days’ food left with them. They had six huskies with them. Huskies, as you know are Eskimo dogs, used as ponies in Antarctic region. They knew that sooner or later they would have to eat those dogs to remain alive.”

“Oh, it was really terrible. But the story is getting interesting. What happened then?”

“They did kill the huskies and ate their flesh, but the flesh was stringy and they could not eat it. In contrast to flesh, they found the liver softer and easier to eat so they took generous quantities of liver. Mertz was a near vegetarian; he could not eat the stringy flesh, so he took more liver than Mawson. Little did he realize that he was taking fatal amounts of Vitamin A in this form. On New Year’s Eve, Mertz began to feel ill. Next day he complained of stomach pains. Few days later both men began displaying typical symptoms of Vitamin A poisoning, although Mawson was affected less. Their skin was falling off their bodies in strips and their hair was dropping out in handfuls. A week later, Mertz fell into a delirious sleep - a sleep from which he never woke. As far as we know, he was the first case of death due to overdose of Vitamin A. Mawson survived, and ultimately did return to Commonwealth Bay."

“This is certainly a most interesting incident doctor.”

“So I was telling you about the vitamin A content of polar animals. With the amounts I told you, you can see that really very little quantities of livers of these animals are required to kill a human being. For instance, it would require about 30 to 90 g of the liver of a polar bear, 80 to 240 g of the liver of bearded seal and 100 to 300 g of the liver of Antarctic Husky to kill a human being. You may think that the livers of these animals are not commonly available. That is true, but Halibut liver oil also contains almost the same amounts of Vitamin A as that of the liver of Polar Bear. About 30 to 90 g of Halibut liver oil could thus prove fatal to a human being, and this is commonly available with the chemists. It is not very difficult for someone to coax another to drink this amount, especially when Halibut Liver Oil is commonly considered to be a health food.”

“So you think someone coaxed Ramlal into drinking this amount of Halibut liver oil?”

“This is exactly what has happened. I have made inquiries, and found that Suresh a person working in the same factory as Ramlal held a grudge against him. Suresh was an educated person - he held a first division in chemistry in college- and yet Ramlal, probably due to his hard work, rose to a higher position than him in the factory. He held another grudge against him, that Rekha, a co-worker whom he loved and wanted to marry was attracted more towards Ramlal.”

“Oh, I see. But how did he coax Ramlal to drink a fatal amount of Halibut liver oil?”

“Ramlal thought that he was not strong enough, and before marriage he could do with some more nutritious foods. Suresh knew about health foods well, and one day he took his advice. Suresh saw his chance and advised him to contact him the next day. Next day he handed him a bottle of Halibut liver oil and asked him to drink copious amounts from there. He told him that it acted as a good aphrodisiac and would serve him well before marriage. Poor Ramlal believed him, and drank almost the whole bottle, which contained 100 g of oil in one go. This is how he died.”

“This is all very well doctor, but how are you going to prove in a court of law that Ramlal died of Vitamin A poisoning?”

“Tarun, I have examined the vitamin A content of Ramlal’s liver and it is more than 40,000 I.U. per g. As you know, a human being should have at the most about 600 I.U. of Vitamin A per g of liver. This proves beyond doubt that Ramlal had Vitamin A poisoning. Added to this is the hospital record which gives us the typical symptoms of vitamin A poisoning. I don’t think the court would have any hesitation awarding sentence to Suresh. Come, let us tell the police to arrest Suresh.”

"That was very clever of you doctor. Without your clever deduction - especially your noticing the peculiar symptoms of Ramlal at the time of his death- everybody would have thought he died of some mysterious natural disease. This was a most interesting discussion doctor. Tell me what are you going to tell me the next time?"

"Tarun, next time, I would tell you about a very interesting poison- Cicutoxin."