( Originally Published 1930's )
The accepted vitamin D benefit accruing to the animal body is one of bone formation, growth, and repair. The theory of vita-min D action is catalitic, or causative. It does not, itself, become a part of the bone, but causes the properly proportionate absorption of calcium and phosphorous which are the essential minerals for bone structure. It is the case of vitamin D playing the carpenter with his hammer fashioning the structural material around which our body is formed.
The right amounts of vitamin D consumption can not be determined for various conditions because it is impossible to know how much of this vitamin is manufactured within our bodies. Nor, can it be determined how much vitamin D is needed by our bodies when we have a well balanced mineral reserve.
The fact is, very little vitamin D is needed by the individual who eats a large amount of mineral bearing food. However, vita-min D does cause a greater absorption of minerals from what food we do eat.
Vitamin D is closely associated with vitamin A in our various foods. Milk, cheese, eggs, and fish livers; all contain liberal amounts of both A and D. In fact, the greater amount of our vitamin D is obtained from these foods.
Some vitamin D is manufactured by the action of sunshine up-on our skin. Under our skin, an oily substance called cholesterol is stored. Sunshine either causes vitamin D to be released from cholesterol, or causes the cholesterol to become vitamin D. That is why vitamin D is sometimes referred to as the sunshine vitamin.
However, there are many people who have perfect bone structure although they rarely see the sun. It is quite possible to disregard sunshine as our supplier of this vitamin. Nevertheless, a good suntan makes one look better, and perhaps feel better.
Rickets, a vitamin D deficiency, is really caused by a lack of calcium and phosphorous in the system. It is a disease, caused by the child not obtaining sufficient milk and green vegetables wherein the bone building minerals are found. It is doubtful that artificial vitamin D will prevent rickets if the child is continued upon a diet lacking milk, green vegetables, and other mineral bearing foods.
But, it is a well known clinical fact that any child, or person, will absorb a greater percentage of calcium out of the food they eat if vitamin D is given as a supplement to their diet.
Vitamin D is quite essential for the growing child and the pregnant mother. However, in either case, it is much more important that foods containing vitamin D be eaten. Because, practically every food which contains vitamin D also contains rich amounts of calcium and phosphorous, the real foundation of structural bone growth.
Vitamin D, in huge doses, is being given to people who have arthritis, and, in some cases it seems to help somewhat. But there are no recoveries from this disease through the use of vitamin D.
On the other hand, vitamin D is the only one of all the vitamins which has been reported dangerous, when indiscriminately used. And, few, if any, authorities name the danger, or explain it. The writer will try and explain the only possible way it can become dangerous.
You will remember, we say arthritis is a deficiency disease; that it is a lack of minerals, particularly calcium and phosphorous, but also, potassium, manganese, sodium, and other minerals which make the hard calcium or lime, porous and flexible. Please re-member, also, that you can not replace a flexible material with something which has no flexibility. Calcium, alone, is not a good repair for bone structure.
Nature knows her own proportions of minerals for the rebuilding of destroyed tissue; just like a cook knows how to make a pie crust that will not need a sledge hammer to break. Vitamin D causes more absorption of calcium than any other mineral. Now, if more calcium is formed than can be proportionately mixed for specific bone repair, there is possibility of the excess being deposited within the walls of the blood vessels. The blood, carrying flee-astray calcium and depositing it within the arteries, causes these vessels to harden. The kidneys are supposed to remove mineral impurities from the system. Many of you readers have heard of kidney stones. Calcium is a portion of these stones.
Since some infection caused you arthritic people to use up your mineral reserve, a deficiency is created. You do not eat enough mineral bearing foods to replace what you have used up. How can you better assure yourself of proper replacement of the minerals and protect yourself than by eating plenty of green leafs, vegetables, tart fruits, and dairy products? These foods contain not only the proper proportions of repair minerals, but they also contain enough vitamin D to cause their absorption. Do not forget that large amounts of vitamin D can be dangerous.
A few hundred units of vitamin D taken with, or in combination with, some mineral preparation is no doubt useful and could do no harm. Certainly, vitamin D, in huge doses, should be taken only by a physician's advice; at least until further clinical tests have proven, or disproves its dangerous possibilities.