Whale liver oil: vitamin A and vitamin D before synthesis

Before chemistry knew how to make them, vitamins were fished for. Those of the fat-soluble group, A and D, concentrate in the liver of marine animals, and the largest liver in the world is that of the blue whale.

Why the liver

Vitamins A and D are not soluble in water but in fats. The body therefore cannot eliminate them in urine: it stores them, and the main storage organ is the liver.

In a marine predator that eats fish and krill, themselves rich in these compounds, the accumulation is considerable. The liver of a blue whale contains about 2.5% of an oil very rich in vitamins, exploited to produce vitamin A concentrates. Set against an organ that on its own weighs more than a tonne, the yield was without equal.

This product must be clearly distinguished from ordinary whale oil, rendered from the blubber. These are two different materials, taken from two different organs, sold on two different markets: one by the tonne for industry, the other by the bottle for pharmacy.

Vitamin D until the 1960s

This was the most important outlet, and the one that lasted longest.

Vitamin D prevents rickets, a disease of bone growth that struck the children of industrial cities on a massive scale, deprived of sunlight by pollution and dark housing. Supplementation became a public health policy in the first half of the twentieth century.

Cod liver oil has remained the most famous, and its memory haunts childhood recollections. But whale liver oil was a major source of vitamin D until the 1960s, less well known because it supplied above all the supplement and fortified food industry rather than the daily spoonful.

What brought it to an end

Chemical synthesis, once again, and not the protection of species.

The structure of vitamin A was elucidated in the 1930s and its industrial synthesis mastered from 1947. Vitamin D is synthesised from plant precursors or from the lanolin of sheep wool grease, an abundant resource that requires no Antarctic season. From then on, extracting vitamins from the liver of a hundred-tonne animal no longer made any economic sense.

The pharmaceutical outlet therefore died out in the 1960s, at the same time as that of glands and hormones, and for the same reason.

A health paradox

It is worth pointing out, because it sheds light on the contemporary subject.

The liver concentrates fat-soluble vitamins for the same physiological reason that it concentrates fat-soluble pollutants. An organ that stores vitamin A well stores PCBs and organochlorine pesticides just as well. At the time of its exploitation, these contaminants did not yet exist in quantity; they would be there today.

To this is added a risk specific to vitamin A, an excess of which is toxic. The livers of certain marine and Arctic predators are concentrated enough to cause acute hypervitaminosis A, a phenomenon well documented in polar explorers who had eaten polar bear or seal liver.

This page is part of our dossier on whale products.