How Supplements Work
Vitamins A and D
Vitamins A and D help maintain bones, epithelial tissue, and a healthy immune system. I'm including them together in this section because they naturally occur together in fish oil and many other supplements. While vitamin E also works very closely with vitamin A, it's better to purchase your vitamin E (and the B and C vitamins) separately rather than all together as one "mega vitamin" supplement so that you can better manage the individual doses, adjusting them to suit your needs. The amounts of A and D combined in fish-liver oil work well together. You can get fish-liver oil from a good, reliable, and very inexpensive source---my favorite company, Puritan's Pride. I've been using them for many years and I know they work. You can order by clicking on the Puritan's Pride logo on the left hand column further down. Be sure to get the A & D combination from fish-liver oils, as it is natural and not toxic.
By the way, I chose this picture of me enjoying the sun at Waimea Bay to remind us of how important sun exposure is to our health, particularly in boosting vitamin D and other substances responsible for calcium assimilation. The latest research also shows sunshine actually protects against cancer. See Recent Studies.
Vitamin A is essential for growth, reproduction, vision, smell, hearing, and taste. In growth, its function is the development of bone, and the development and maintenance of epithelial tissue. Growing and maintaining healthy epithelial tissue is one of the important factors in overcoming allergies and asthma.
Epithelial cells, or epithelial tissue, make up the surface layer of the lining of all the openings, passages and cavities of the body---the nose and its passages and sinuses, the throat, lungs, stomach, intestines, vagina, and urinary tract. It consists of a surface layer of epithelium (epithelial cells), a membrane, and an underlying layer of connective tissue.
This lining is called the mucous membrane, and is the first line of defense against harmful foreign particles---antigens---gaining entrance to the body. Once foreign particles enter the body, an all-out attack ensues, the inflammatory response, to immobilize and get rid of the potentially harmful invaders. This response manifests itself as swelling in the affected site, whether it's the hives or itching of the skin, runny nose, redness of the eyes, scratchy, itchy throat, and gastric disturbances of allergies, or the wheezing of asthma from swollen bronchial tubes.
Vitamin A can be the difference between having nice, tightly-knit mucous-producing epithelial cells which successfully block invaders, and having a loose, spongy cell barrier that allows invaders to enter.
Vitamin A also plays a particularly important role in preventing or clearing up infections of the skin, the cornea of the eye, and the mucous membranes. It is also necessary for the production of antibodies and white blood cells, as well as for stimulating the production of the mucous for the membrane.
Mucous-secreting cells are normally present in the epithelium. When vitamin A is undersupplied, millions of epithelial cells on the surface of the mucous membranes die and accumulate; cells lining the body cavities can no longer secrete mucous, which normally traps foreign invaders, washes them away, protects the underlying tissues, and carries white blood cells. Meanwhile, the accumulation of dead epithelial cells serves as food for bacteria. All of these conditions are perfect for infections to flourish, as well as allowing pollen, dust, mites, pollution, or any other antigen, access to the inner tissues, and setting off our allergies or asthma.
Some asthma sufferers living in dry climates think that the dry air dries out their mucous membranes and allows things such as dust to get into their lungs, setting off asthma attacks. If this were so, then everyone on the planet who lives in a dry climate would have asthma. What is really happening is that a lack of vitamin A or any of the other nutrients needed for the continuous regeneration of the mucous membranes is the real culprit.
Often moist air does relieve the swollen airways during an asthma attack; it may be soothing, but it is not a cure. The underlying nutritional requirements must still be met in order for healing to take place and to stop asthma attacks altogether.
Speaking of moist air, some asthma sufferers living in humid climates think that the congestion of asthma can be "dried up" by a dry climate. Again, if the asthmatic has a shortage of vitamin A or any of the other nutrients needed for the continuous regeneration of the mucous membranes, the problem will recur.
When changing climates seems to work for some, it is actually due to some other change. For example, if a person in Hawaii develops allergies to certain antigens (such as cockroach particles), and moves to Colorado (where I hear there are cockroaches, but they must be very rare because I've never even seen one the whole 14 years we've lived here) and, like me, never comes across one of da buggahs, then the person will not have the allergy symptoms they had before (if roaches were the only thing they were allergic to). But without improved nutrition, and the same old leaky cells of the mucous membranes, the person will eventually develop an allergy to something else, something in the environment in Colorado---sagebrush, for example. Then once they're allergic to sagebrush, moving back to Hawaii would seem to "cure" that particular allergy. And, in the meantime, if the person happened to lack vitamin A and started taking it and built up their mucous membranes to be nice and strong, then the cockroach dust wouldn't trigger an allergic reaction anymore (and they could stay in Hawaii).
Getting back to vitamin A, another reason for obtaining adequate amounts of this vitamin is to enable the body to fight infections.
A five-year study revealed that individuals whose blood was consistently low in vitamins A and C contracted by far the most infections. The blood level of vitamin A drops sharply during infections, is often lost in the urine, and may disappear completely during measles and high fever. Also, cortisone and a number of drugs rapidly deplete the body of its vitamin A stores and tremendously increase the need for it. Unless vitamin A is generously supplied, the body is left susceptible to more serious infections. I saw many children of parents in our support group hospitalized time and time again with pneumonia. It was always the ones who had been taking a lot of cortisone/steroid drugs for some period of time. With their airways continually forced open by the drugs and their airway mucous membranes in a deteriorated condition, it's not hard to see why pneumonia was so common, much less the frequent asthma attacks.
Sources of vitamin A: Cream, butter, whole milk, eggs, liver, fish oil, and yellow and green vegetables and fruits. The "vitamin A" in vegetables and fruits is actually carotene, a substance that changes into vitamin A in the body. It is not well absorbed unless the fruits and vegetables are unusually soft; and as far as the other sources mentioned go, many people actually avoid those sources. Therefore, I think it would be safe to say that most individuals obtain far too little vitamin A unless their diets are supplemented.
If you asked me how much to take in the way of supplements, for adults, I would suggest 25,000 units of vitamin A a day, along with a minimum of 200 units of vitamin E (d-alpha tocopherol acetate) to protect the A. Always take these fat-soluble vitamins with a meal containing fat.
Because of insufficient fat, babies and small children cannot well absorb vitamins A and D from concentrates or capsules, so the best source of these vitamins for them is good old-fashioned cod-liver oil. Keep it refrigerated, and give it daily with at least 50 units of vitamin E.
Vitamin D is essential for good teeth and bones because it plays an important part in calcium absorption through the intestinal wall and it controls enzymes necessary to deposit minerals in bones and teeth. There is also much evidence from several recent studies that vitamin D actually helps fight cancer. It's also mportant in relation to asthma and allergies because of the anti-inflammatory medications (steroids/cortisone) commonly used by many. These drugs cause calcium to be withdrawn from the bones, large amounts of calcium to be lost in the urine, and protein synthesis to be retarded. These must, then, be replaced by adequate nutrition including vitamin D so that calcium can be absorbed. However, if digestion is faulty, without enough bile acids being produced, vitamin D supplements, along with essential fatty acids (EFAs), carotene and vitamins A, E, and K, are not absorbed.
Sources of vitamin D: Vitamin D is naturally synthesized from the effect of summer sunshine in the oils on our skin, if the oils have not been washed off. The oils must first be on the skin, then exposed to ultraviolet light, and later absorbed back into the body. If you take a shower before going into the sunshine, the oils are washed off, and no vitamin D is formed; if you do not bathe before exposure to sunshine but bathe immediately afterward, the oils are removed before the vitamin can be absorbed into the body. Most of the oils are washed off by cold water, and still larger quantities by warm water; warm soapy water does the job thoroughly. Sunscreen prevents the formation of vitamin D. Studies have shown that most people are deficient in vitamin D, particularly in the winter. The vitamin does not naturally occur, or is extremely scanty, in ordinary foods (it is purposely added to milk at the dairy), so supplements should be taken to insure good health, especially if you do not drink much milk. The ideal intake is unknown. Research indicates that 2,500 units daily is advantageous for adults, but this quantity should be supplied only by the natural vitamin D from fish-liver oil and never from the synthetic irradiated ergosterol.
Almost all toxicity has resulted from vitamin D artificially produced by irradiation (viosterol) and not from that in natural fish-liver oils or fish-liver concentrates. Yet fear of toxicity has caused the National Research Council to recommend only 400 units daily for persons of all ages, regardless of the source of the vitamin or individual variations in requirements. A teaspoon of cod-liver oil daily might be enough for children
and will never be toxic. And make sure they (and you) get sunshine as often as possible. I shouldn't have to mention not to overdo it according to skin type; lengthen exposure gradually so as not to get sunburned.
Another benefit of sunshine is that it stimulates the production of calcitonin and parathyroid hormones. Even after calcium is absorbed into the blood, it will still not go into the bone or other cells unless directed by these hormones. Both are released by the parathyroid glands and help control both the removal and deposition of calcium in the cells. The parathyroid glands are regulated by the pituitary gland located directly behind the eyes as it is stimulated by sunlight. Glasses, particularly sun-glasses, block much of the spectrum required for hormone regulation. Ancient health practices, such as Ayurveda, say to spend at least a few minutes each day looking towards the sun with the eyes closed in order to stimulate the hormones of the pituitary system. (I checked with my optometrist, and he said this was perfectly safe for the eyes. He said the eyelids do completely block the ultra-violet rays so that no damage is done to the eyes.)
In conclusion, you can see how important vitamins A and D are to building health in overcoming asthma and allergies and many other conditions. However, all of the other vitamins are equally important, as they all work together in the body, and good health cannot be achieved without all of them, plus nutritious food, as well as a healthy digestive system to get all of this into the blood stream in the first place. Also, it's important to know that there are nutrients not yet discovered that are present in foods and that the body needs them just as much as the nutrients we do know about. Animal studies have been done where, instead of food, the animals were fed all of the individual, known nutrients. They all died. So concentrate on eating well as much as supplementing.