Vitamin A poisoning

Post-ingestion from a-, (3- y-carotene other carotenes Sir Douglas Mawson nobly denied himself but gave dog liver to his fellow Antarctic explorers who died of Vitamin A poisoning Post-ingestion from a-, (3- y-carotene other carotenes thence isomerization of all /rcm.s-Retinoic acid... 

Wisse Smit J, Pott Hofstede D. Vitamine-A-intoxicatie bij volwassenen. [Vitamin A poisoning in adults.] Ned Tijdschr Geneeskd 1966 110(1) 10-11. 

Gottrand F, Leclerc F, Chenaud M, VaUee L, Gaudier B. Une cause rare d hydrocephalie du nourrisson I intoxica-tion chronique par la vitamine A. [A rare cause of hydrocephalus in an infant chronic vitamin A poisoning.] Arch Fr Pediatr 1986 43(7) 501-2. 

The authors emphasised the need for a complete dietary history in any child suspected of food poisoning, and the consideration of xmusual causes such as vitamin A poisoning. 

Covalent synthesis of complex molecules involves the reactive assembly of many atoms into subunits with aid of reagents and estabUshed as well as innovative reaction pathways. These subunits are then subjected to various reactions that will assemble the target molecule. These reaction schemes involve the protection of certain sensitive parts of the molecule while other parts are being reacted. Very complex molecules can be synthesized in this manner. A prime example of the success of this approach is the total synthesis of palytoxin, a poisonous substance found in marine soft corals (35). Other complex molecules synthesized by sequential addition of atoms and blocks of atoms include vitamin potentially anticancer KH-1 adenocarcinoma antigen,... 

The hver of sharks and other oily fishes sometimes accumulate toxic levels of vitamin A, and cases of acute poisoning have been reported both among Eskimos and the Japanese. 

While the human body can remove an excess of any water-soluble vitamin, excesses of fat-soluble vitamins are more serious. Early arctic explorers discovered that the Inuit regarded seal liver and polar bear liver as taboo and must not be eaten. Those explorers who ignored this advice risked retinol poisoning as the livers of both these species are rich in retinol (vitamin A) that can not be excreted. The effects of retinol poisoning are extremely unpleasant. It is for this reason that fortification with fat-soluble vitamins is not likely to be undertaken. 

The nature of poisons in sharks is a complex one. Vitamin A may be a causative factor in some shark species. The liver of sharks contains waxes, diacyl glyceryl ether, and hydrocarbons of which squalene and pristane are the most predominant (11). Sakurai and Masukara (82) and Kaneda,et al (83) demonstrated that squalene and wax can cause seborrhea and lethalities in rats. These studies suggest that the shark livers are not suitable for food. There is also clinical evidence that the ingestion of livers from tropical shark species may produce a ciguatera-like syndrome. 

Fish Liver Poisoning. The livers of large fish species such as sharks, tunas, and sea bass may cause intense headaches, vomiting, facial edema, fever, and severe desquamation. Onset of symptoms is from 30 minutes to 12 hours. All of these fishes contain extremely high levels of vitamin A in their livers. As the fish grows, the concentration of vitamin A in the liver increases (94-96). ... 

Unusual features of vitamin A as observed by some investigators include (1) decreases serum cholesterol in large-quantity administration (chicks) (2) dietary protein required to mobilize liver reserves of vitamin A (3) decreased quantities in tumors (4) coenzynre Q10 accumulates in A-deficient rat liver (5) Ubichromenol-50 accumulation in A-deficient rat liver (6) retinoic acid functions as vitamin A except for visual and reproductive functions (7) anti-infection properties and anti-allergic properties (8) decreases basal metabolism (9) detoxification of poisons in the liver aided by vitamin A and (10) vitamin A is involved in triose —> glucose conversions. 

Acute poisoning with vitamin A produces symptoms such as drowsiness, sluggishness, irritability, an irresistible desire to sleep, severe headache, and papilledema. In some cases papilledema is the only symptom (SEDA-11, 333) (16,17). In young children, raised intracranial pressure with bulging of the fontanelle, papilledema, and diplopia have been observed (SED-8,799, 801) (SEDA-15, 411) (18). 

Navarro M, Acevedo C, Espinosa L, Pena A, Picazo ML, Larrauri M. Intoxicacion por vitamina D3 y secuelas irre-versibles. [Vitamin D3 poisoning and irreversible sequela.] An Esp Pediatr 1985 22(2) 99-106. 

Leeson PM, Fourman P. Acute pancreatitis from vitamin-D poisoning in a patient with parathyroid deficiency. Lancet 1966 1 1185. 

Warfarin is a poison that inhibits the action of vitamin K by preventing gla residue synthesis (Sect. 11.2.2) and therefore causes an osteocalcin deficiency. Mice in which the... 

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