From Whole Health Source: http://wholehealthsource.blogspot.com/2009/12/butyric-acid-ancient-controller-of.html
After thinking about it, I've decided that butyrate must have been a principal component of Dr. Weston Price's legendary butter oil. Price used this oil in conjunction with high-vitamin cod liver oil to heal tooth decay and a number of other ailments in his patients. The method he used to produce it would have concentrated fats with a low melting temperature, including butyrate, in addition to vitamin K2***. Thus, the combination of high-vitamin cod liver oil and butter oil would have provided a potent cocktail of fat-soluble vitamins (A, D3, K2), omega-3 fatty acids and butyrate. It's no wonder it was so effective in his patients.
It seems that mixing melted butter with cod liver oil could be a pretty potent vitamin package?
And here is the passage in Ch. 16 of Dr Price's book Nutrition and Physical Degeneration:
The program that I have found most efficient has been one which includes the use of small quantities of very high vitamin butter mixed in equal parts with a very high vitamin cod liver oil. A simple method of preparing the butter is by melting it and allowing it to cool for twenty-four hours at a temperature of about 70° F., then centrifugalizing it which provides an oil that remains liquid at room temperature. When this butter oil is mixed in equal parts with a very high-vitamin cod liver oil, it produces a product that is more efficient than either alone.
It should be used within a couple of weeks of the time it is mixed. It is desirable that this material be made available in various parts of the country. Even the high-vitamin butter produced on the early summer growth of grass put in storage and used during the winter will go far toward solving our great national problem of shortage of fat-soluble vitamins. The quantity of the mixture of butter oil and cod liver oil required is quite small, half a teaspoonful three times a day with meals is sufficient to control wide-spread tooth decay when used with a diet that is low in sugar and starches and high in foods providing the minerals, particularly phosphorus. A teaspoonful a day divided between two or three meals is usually adequate to prevent dental caries and maintain a high immunity; it will also maintain freedom from colds and a high level of health in general.
This reinforcement of the fat-soluble vitamins to a menu that is low in starches and sugars, together with the use of bread and cereal grains freshly ground to retain the full content of the embryo or germ, and with milk for growing children and for many adults, and the liberal use of sea foods and organs of animals, produced the result described.