Fitness

It is not enough to see that calcium is adequately supplied; it must pass through the intestinal wall into the blood before it can be of value. Calcium must first be dissolved by hydrochloric acid in the stomach. If this acid is absent, as it usually is when persons have the tongue symptoms described on page 63, calcium cannot be absorbed, though the supply be generous. Even when the stomach acid is normal, the added citric acid supplied by a glass of orange juice or lemonade has been found to increase calcium absorption markedly. Lactose, the sugar obtained by drinking milk, causes a pronounced increase in calcium absorption because it is broken down by intestinal bacteria into lactic acid. If the diet is excessively high in phosphorus, calcium and phosphorus combine in the intestine to make insoluble salts which do not dissolve even in acid. The taking of soda or any alkaline substance, which neutralizes the food and stomach acids, or the eating of candy or other concentrated carbohydrate, which stimulates the flow of alkaline digestive juices, decreases or prevents calcium absorption.

After calcium is once soluble, it must next combine with fat, making a soap which dissolves as readily in water as ordinary soap dissolves in a bathtub; in this form, the calcium passes across the intestinal wall into the blood. If so much fat is eaten that it cannot be absorbed, soap is formed, and both the fat and calcium are lost in the feces; this soap becomes hard, often causing constipation as well as robbing the body of valuable calcium. The stools of persons attempting to gain weight by drinking rich milk and eating quantities of fat often look like shiny soap; instead of gaining, such people usually become thinner because the loss of calcium results in greater nervousness and over activity.

Conversely, almost any person who stays on a fat-free diet absorbs little or no calcium from his food. For example, leg cramps and other calcium-deficiency symptoms suffered by women during pregnancy or menopause can sometimes be relieved more quickly by fat than by extra calcium. More calcium is absorbed from yogurt and buttermilk, which supply both fat and lactic acid, than from sweet whole milk. If you wish to use skim milk, drink it at a meal when you have a salad tossed with oil. Using fresh or powdered skim milk without fat being obtained simultaneously may be actually dangerous; besides calcium being lost, the need for vitamin B2 is increased.

After calcium has reached the blood, the next task is to prevent it from being lost from the body. If cholin and/or linoleic acid are undersupplied, if the protein intake is inadequate, or if thyroid, benzedrene, or certain other drugs are used, large quantities of calcium may be lost in the urine. Even a slight increase in protein intake can markedly increase calcium retention. The most important factor, however, is the quantity of phosphorus in the diet in relation to the amount of calcium. Ideally, no more than twice as much phosphorus as calcium should be obtained; yet persons often ingest 10 times more phosphorus than calcium. Aside from such urinary losses, calcium and phosphorus which might be thought of as worn out are lost daily in the feces.

Phosphorus is necessary to the life processes of every cell not only in all animals but in all plants. The American diet, poor in calcium, is therefore rich in phosphorus. In the maintenance of bones and teeth, calcium is used in chemical combination with phosphorus. If calcium is undersupplied in proportion to phosphorus, there is nothing for phosphorus to combine with. In this case, phosphorus is excreted in the urine. There is, however, always calcium in the blood. Unfortunately, urinary phosphorus is excreted in the form of calcium-phosphorus salts, and the body is robbed not only of its limited calcium supply but of phosphorus which may also be greatly needed. For these reasons, calcium gluconate and calcium lactate are preferable to calcium salts containing phosphorus.

Liver, yeast, and wheat germ are unusually rich in phosphorus and yet poor in calcium; if large quantities of these foods are consumed, calcium lactate or calcium gluconate should be obtained simultaneously. When such a precaution is not taken, the proportion of phosphorus to calcium may become so high that the excretion of the excess phosphorus in the urine can induce a severe calcium deficiency. Sometimes a person who uses little or no milk becomes enthusiastic about obtaining large amounts of the B vitamins; his high intake of phosphorus and lack of calcium can cause him to become a nervous wreck. Phosphorus, calcium, and vitamin D are interdependent. When liberal quantities of milk, cultured buttermilk, yogurt, and foods prepared with fresh and powdered milk are used, calcium is supplied, and no problem arises unless large amounts of liver, yeast, and/or wheat germ are eaten temporarily; in this case, a calcium salt can both prevent harm and be of great value.

Excess calcium which is absorbed and retained is stored in the shafts at the ends of the long bones as a lacy network of bony structure known as trabeculae, absent when no excess minerals have been available. You probably have noticed this lacy structure when a soup bone has been cut lengthwise. Calcium thus stored can be used at times of dietary insult; thus health can be protected. When no minerals are stored, calcium and phosphorus, aided by a hormone from the parathyroid glands, are removed from the bones to supply the needs of the soft tissues. The amount of calcium in the blood therefore remains at a normal level even when bones become progressively more porous and fragile, teeth become susceptible to decay or erosion, and multiple symptoms of calcium deficiency become evident. When deficiency symptoms are persistent, the bones are probably in a precarious condition.

Instead of bones being lifeless structures, unchanging after the cessation of growth, a continuous tidal flow of minerals passes in and out of them every hour of life. If sufficient calcium is obtained and absorbed, the tide flows into the bones, building and repairing until all porosity is gone and dense mineralization is formed; any excess is then stored in the trabeculae. When too little calcium is obtained, the tide Haws first from any calcified trabeculae; if no minerals have been stored, calcium and phosphorus are removed from the bones to supply the calcium needs of the soft tissues.

The calcium content of milk varies with the feed of the cow and season of the year; a quart of milk may contain 800 to 1500 milligrams. Powdered milk, made from summer milk when the supply is generous and green food is usually available, contains more calcium than does average winter milk. Powdered milk should be used liberally in cooking, always in recipes containing fat. If optimum health is to be obtained, adults should have daily at least one gram of calcium, the amount obtained from four glasses of average milk, yogurt, or cultured buttermilk. Still larger amounts may be advantageous. In times of prosperity, the daily calcium intake of the Finns and Swiss averaged six grams; many primitive races obtain even larger amounts of calcium. If a small excess is allowed for daily storage, large amounts of calcium would never be needed nor would calcium deficiencies ever exist.

Your own disposition can probably tell you the adequacy or inadequacy of your calcium intake, absorption, and retention. If it is good, no one can enjoy it more than yourself.