Dr. Mellanby fed puppies with separated milk, wheat bread, linseed oil, yeast, orange or lemon juice and salt. They developed rickets within six weeks. The diet was ample in calorific content, Its food constituents were well distributed. The yeast supplied water-soluble B as the antineuritic vitamine, and the orange juice, a vitamine preventing scurvy (see Chapter xiii (Vitamines And Scurvy)). The linseed oil is a characteristic fat, but it is poor in fat-soluble A. As little as one-third of an ounce of butter or codliver oil completely prevented rickets. Remember that both of these are rich in fat-soluble A. Neither cottonseed, nor olive oil had any curative effect. "The above facts are in keeping with the idea that rickets is a disease primarily due to a deficiency of fat-soluble A vitamine. It is believed that the substances associated and contained with fat-soluble A are particularly concerned in the calcification process of bone and teeth" (that is in the utilization of calcium for the building of bone and teeth).

Let us hasten to add that Dr. Mellanby is a scientist of much distinction, and his opinions carry weight everywhere. During the war the British Government appointed a Medical Research Committee to investigate some of the pressing medical problems that arose as a result of the war. Among these problems was one dealing with infant diet, particularly the bearing of vitamine content in such diets. The Medical Research Committee in turn requested Professor Hopkins of Cambridge and Dr. Chick of the Lister Institute, to prepare a special report on the subject. If you turn back to page 91, you will recall this Professor Hopkins as the person who conducted a number of pioneer investigations on vitamines. During the last few years Miss Chick's researches on vitamines have won high praise on both sides of the Atlantic. After a very careful examination of Dr. Mellanby's work, both Professor Hopkins and Dr. Chick adopted Dr. Mellanby's view that the absence of fat-soluble A in the diet of infants, or its presence in insufficient amounts, is the primary cause of rickets. Professor Hopkins and Miss Chick drew up a report incorporating these views, and this report was adopted by the Medical Research Committee. The report was, and still is, very extensively used as a guide for those engaged in the administration of food relief in famine-stricken countries.

Further Confirmation Of The View That Absence Of Fat-Soluble A Vitamine Gives Rise To Rickets

Investigations by Japanese doctors have confirmed the views expressed by Dr. Funk and Dr. Mellanby. Among a group of children suffering from rickets, whose diet consisted of rice, barley, cereals, beans and other vegetables, a cure was very rapidly accomplished by the addition to such a diet of cod-liver oil, but not of olive oil. The former is rich in fat-soluble A; the latter is not.

Dr. Bloch had similar experiences in his clinic in Copenhagen. During the years 1912 to 1916, 49 cases of what was apparently rickets were very carefully examined by him. "The infants were pale, flabby and very thin, with dry, scaly and very shriveled skin. Of the 49 infants, 20 were between six and twelve months of age, 15 from two to six months, and 14 over one year. They would scream and twist and turn, and wanted to be let alone. The malnutrition was extreme in many cases; for example, one baby of nine months weighed nine pounds, one of a year weighed 131/2 pounds, another aged two years weighed 14 pounds. Their diet consisted of an indefinite amount of skimmed milk that had been pasteurized and cooked again in the home. Oatmeal-gruel and barley soup constituted an important part of their dietary. ... A cure was obtained by means of codliver oil, though in almost every instance breast milk or raw cow's milk was also given."

Though what is now to be stated has been stated in a former chapter, I shall repeat it again, for it needs a number of repetitions: one vitamine factor in the absence of the other vitamine factor - or rather factors, as we shall see - does not cure. Where, as in the above examples, we speak of the fat-soluble A as being the curative agent, we imply that water-soluble B, etc., is also present; and vice versa.

And again I must emphasize that not all the vitamines in the wide world are of any use if the fuel needs of the body are not satisfied; or if there is not a well-balanced distribution of fat, protein, carbohydrate, etc.

Dr. Hess's Views

If I have referred to several investigators in European countries as favoring the view that rickets is a vitamine deficiency disease, - one due to the lack of fat-soluble A - I cannot overlook the work of a prominent American physician, Dr. Hess, which would tend to modify such a conclusion. Dr. Hess reports a number of cases where children have had rickets even though their diet included an abundance of fat-soluble A. And on the other hand, he has noticed perfectly normal children whose diet included little or no fat-soluble A. Still he does not attempt to overthrow entirely the Funk-Mellanby theory of the causation of rickets, as the following extract from Dr. Hess's paper shows: "Our experience leads us to believe that except under exceptional circumstances - as in time of war - the danger to the infant and to the child from a deficiency of the fat-soluble factor is one not to cause great apprehension. It is true that this principle is by no means so widely distributed in nature as the water-soluble vitamine, but, on the other hand, infants seem able to thrive for long periods on very limited quantities, provided the diet is otherwise complete. The great danger arises from diets composed merely of cereal and water, or a perhaps insufficient amount of buttermilk or skimmed milk. It is probably true that a catastrophe will result if the incomplete diet is maintained for years, or even sooner in a susceptible individual, as is well known to be the case in scurvy and beriberi. In formulating dietaries for infants and children, therefore, this food factor should be borne in mind and be regarded as an essential constituent."

The last sentence is really the one that matters. Though by no means certain that fat-soluble A plays as important a part in rickets as water-soluble B does in beriberi, Dr. Hess does not advise that the fat-soluble vitamine be discarded. In the preparation of diets for infants and diets for adults, the accumulated researches of many men in many countries deserve careful consideration. The consensus of opinion is that fat-soluble A is a vital factor in health, and that its absence in a diet is one of the causative factors in the development of rickets.

Distribution Of Fat-Soluble A

Despite its name, fat-soluble A is by no means confined to those foods that are usually regarded as rich in fat. It is quite abundant in the vegetable world. Even the tomato, always considered one of the poorest of foods from the point of view of calorific value, is quite rich in fat-soluble vitamine, and incidentally in one or two other vitamines; so that the oft-heard cry that buying tomatoes means buying little more than so much water, is very far from the truth.