474
JOURNAL oa Cnsanwu, EDUCATION
A p m , 1927
THE VITAMINS. VI H. C. SHBR~UW, COLUMBIA UNNI~RSITY, NEW YORKCITY
Summary of Some of the Properties of Vitamins A, B, C, D, and E
On the basis of relative solubilities these five vitamins are divided into two groups: the water-soluble vitamins B and C and the fat-soluble vitamins A, D, and E. It seems fairly certain that neither of the watersoluble vitamins bears any close chemical relationship to any of the fatsoluble vitamins. Thus the separation of these five vitamins into two groups on the basis of their relative solubilities in water and fats, while it is doubtless superficial and may prove chemically meaningless, is not likely to do violence to any chemical relations which may be established later. Whether the water-soluble vitamins B and C are chemically related to each other we do not know; it seems unlikely. Vitamin B is in all probability a nitrogenous base (perhaps also an organic acid) ; regarding vitamin C we have no equally strong evidence, but such indications as we now have seem to point rather in other directions-certainly it is a much more easily oxidizable substance than is vitamin B. Also vitamin C does not seem to resemble vitamin B in behavior toward adsorbents. Both vitamins B and C are fairly diffusible through ordinary membranes, and fairly soluble in alcohol or alcohol-water mixtures. There is no evidence that they are in any sense interchangeable, nor in any definite way interrelated in their nutritional functions; but each in addition to its specific effect, as antineuritic and antiscorbutic, respectively, is needed for growth (with the possible exception of C in some species) and has an influence upon the ability of the body to resist invasion by pathogenic bacteria. Of neither vitamin B nor C does the animal body appear to be able to store any large reserve; but whereas all animals which have been studied seem to need vitamin B, some species of animals are able to thrive with little if any vitamin C in their food. Whether this is because they synthesize vitamin C, or do not employ it in appreciable amounts in their nutritional processes (possibly using somethmg else in its place), we do not know with certainty; but the fact that livers of rats and of chickens have been found to contain vitamin C when these animals had been for long periods on diets apparently devoid of it, seems to suggest that, for certain species a t least, there may possibly be sources of vitamin C within the animal body-again unlike vitamin B. Beyond the fact that some vitamin C is formed in the sprouting of seeds, very little is yet known regarding the where, when, or how of the production of vitamins B and C in plants. Vitamin B appears to be much more uniformly distributed in the various tissues and juices of plants and animals than is vitamin C.
VOL 4, No. 4
475
TREVITAMINS. VI
"B"
Bread (Water). . . . . . . . . . . . . . . . . . . . . . . . . . . . Bread (Milk) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bread, Whole Wheat (Water). . . . . . . . . . . . . . . Bread, Whole Wheat (Milk). . . . . . . . . . . . . . . . Barley (Whole). . . . . . . . . . . . . . . . . . . . . . . . . . . Corn, Yellow.. . . . . . . . . . . . . . . . . . . . . . . . . . . Oats.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rye, Cracked. . . . . . . . . . . . . . . . . . . . . . . . . . . . Wheat, Kernel.. .......................... Wheat,Bran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Liver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kidney. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Brains.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fish, Fat.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fish,Rw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : . . Milk. F m h (Unpasteurized). . . . . . . . . . . . . . . Milk, Condensed.. . . . . . . . . . . . . . . . . . . . . . . . . . Milk, Evaparated.. . . . . . . . . . . . . . . . . . . . . . . . Milk, Dtied (Whole). . . . . . . . . . . . . . . . . . . . . Milk, Skimmed.. . . . . . . . . . . . . . . . . . . . . . . . . . Buttermilk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Butter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cheese. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Eggs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Almonds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coconut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hickory Nuts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Peanuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Walnuts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tomato (Raw or Canned). . . . . . . . . . . . . . . . . . Beans,Kidney . . . . . . . . . . . . . . . . . . . . . . . . . . . . Beans,Navy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Beans. String.. . . . . . . . . . . . . . . . . . . . . . . . . . . . ....... Beets.. . . . . . . . . . . . . . . . . . . . . . . .. Cabbage, Raw.. . . . . . . . . . . . . . . . . . . . . . . . . . . Cabbage, Canned.. . . . . . . . . . . . . . . . . . . . . . . . . Cabbage, Cooked Briefly.. . . . . . . . . . . . . . . . . .
+ + ++ ++ ++ ++++
"C"
-
?
-
-
? ++ +++ +++ ? ++ ++ + ? ++ + +? + ? ++ ++ ++V ++ +V? ++ ++ +v + +V ++ +V ++ +V ++ + * ++? ++ -* ++ * ++ * ++ +++ +++ +++ ** +++ ++ + + + +++ +++ * ++ +
++
+. ...Contains the Vitamin. ++....Good source of the Vitamin. +++... .Excellent source of the Vitamin.
-. . . .No appreciable amount of the Vitamin. ?.
. . .Doubt as to presence or relative amount.
* . . . .Evidence lacking or insufficient.
V. .. .Variable.
(Bureau of Investigation of the American Medical Assodation, 1926.)
VITAMINS IN FOODS(Concluded) "A" Carrot, Raw.. ............................ Carrot, Cooked.. . . . . . . . . . . . . . . . . . . . . . . . . . . Cauliflower. .............................. Dandelion Greens.. . . . . . . . . . . . . . . . . . . . . . . . Lettuce (Garden). ......................... Onions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Parsnip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Peas. Fresh. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potato (Boiled). . . . . . . . . . . . . . . . . . . . . . . . . . . Sweet Potato. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rutabaga . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Spinach, Fresh.. . . . . . . . . . . . . . . . . . . . . . . . . . . Spinach,Canned . . . . . . . . . . . . . . . . . . . . . . . . . . Squash. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Turnips. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Apples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bananas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GrapeJuice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Grapefruit.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lemon Juice... . . . . . . . . . . . . . . . . . . . . . . . . . . . . Orange Juice.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pineapple (Raw or Canned). . . . . . . . . . . . . . . . Raspberries (Raw or Canned). . . . . . . . . . . . . . . Peaches (Raw or Canoed). .................
++ ++ + ++ ++ ? -
++ +
+-+
+++ +++ +-+ +? ? ?
-
+ +* +
++
"C"
+
"D"
+V ?
+ +++ ++ ? +++ +? + +++ +++ +++ ?
+
+
+
+++
++ + + ++ +++ +++ +++ +++ ++
-
The fat-soluble vitamins A, D, and E all seem to be closely related to the group of substances known as "sterols;" and, therefore, may not improbably be chemically related to each other, though this is by no means certain. The occurrence in connection with fats and the known physical properties of the fat-soluble vitamins plainly entitles them to classification among the lipoids; but it is not customary to call them lipoids because their most characteristic and most significant properties, namely, their vitaminic potencies, set them off so strikingly from all of the lipoids previously known. There is no evidence that any of these fat-soluble vitamins contains any other chemical elements than carbon, hydrogen, and oxygen; and without repeating here the summaries of properties given in connection with each (for each of the papers of this series is itself merely a condensed summary), it may be recalled that vitamin A very closely resembles the typical sterols in its chemical and physical properties so far as these are yet known, and that vitamin D is known to be derivable from one or more of the typical sterols by the action of ultra-violet light. Also vitamins D and E seem to show a close similarity in their known chemical and physical properties. They seem much more resistant to heat and oxidation than does vitamin A, although vitamin A is doubtless more stable than is generally supposed.
All three of the fat-soluble vitamins are formed in plants; vitamins A and D, a t least, in the green parts and under the influence of sunlight. This seems probably true of vitamin E also in view of Evans' observation of the greater vitamin E content of the milk of cows when on fresh green pasturage. As the animal body has the power of storing fat-soluble vitamins to a very important degree and of furnishing them for their offspring through the medium of milk and of eggs, some foods of animal origin are very important sources of these vitamins, even though i t seems probable that no vitamin A or E originates in the animal body. One of the important services of farm animals to man is the gathering and concentrating, chiefly in the fat of milk and of eggs, the fat-soluble vitamins of such coarse, leafy foods as are not well suited to direct human consumption. In the case of vitamin D i t would seem that there is also an actual production of this or some nutritionally equivalent substance in the skin of the animal, whence i t is conveyed by the blood to other parts of the body. With these few words by way of summary of the relationships and differences of the water-soluble and the fat-soluble vitamins, respectively, let us now pass to a brief, concludmg glance a t the vitamins (especially the longer known members, vitamins A, B, and C) as a group, and their significance in the practical problem of the human food supply. As they are not all related chemically and are in no wise interchangeable in nutrition, i t may well be questioned why the vitamins should be grouped together. Doubtless it is largely due to the fact that they all differ from the previously known food constituents in being organic foodstuffs which occur only in very small quantity and yet function in newly discovered and striking ways in nutrition. One other thing which they seem to have in common-at least the three for which we have methods for quantitative determination of relative amounts, viz., vitamins A, B, and C-is that, like fresh air and unlike most other constituents of foods, they seem to be beneficial in amounts many times greater than the amounts which are actually needed. If we eat several times the amount that we need of f a t or carbohydrate, we must soon sufier either from indigestion or obesity; if of protein, we suffer in other ways; but of vitamins A, B, and C there seems no danger of any disadvantage from an intake of almost unlimited liberality. Assuming that we do not experiment with "concentrates" or other drug forms of vitamin but get our vitamins in our daily food, there seems to be no limit to the extent to which the foods now known to be important sources of vitamins A, B, and C-notably milk, vegetables, and fruit-may wisely be made increasingly prominent in the dietary. The more largely we satisfy our appetites and energy requirements with foods of these types,
the better the margin of safety in our intake of vitamins A, B, and C, and the better our chances of resisting infections and enjoying the highest attainable degree of positive health. As an impersonal summary of the values of numerous staple foods as sources of vitamins A, B, C, and D, we have reproduced, in tabular form. the chart recently published by the American Medical Association.
