VITAMINS - Our Bodies Cannot Get Enough From Food
We know very little, and yet it is astonishing that we know so much, and still more astonishing that so little knowledge can give us so much power.
-- Bertrand Russell
"I believe that you can, by taking some simple and inexpensive measures, lead a longer life and extend your years of well-being. My most important recommendation is that you take vitamins every day in optimum amounts to supplement the vitamins that you receive in your food. Those optimum amounts are much larger than the minimum supplemental intake usually recommended by physicians and old-fashioned nutritionists. . . . My advice that you take larger amounts of C and other vitamins is predicated upon new and better understanding of the role of these nutrients - they are not drugs - in the chemical reactions of life."
Thus begins Chapter 1 of perhaps the best popular book about human health, How to Live Longer and Feel Better.1 The author was Linus Pauling, arguably the greatest scientist who ever lived. The breathtaking scope of his scientific knowledge - not to mention his monumental contributions to our understanding of chemistry, physics, molecular biology, and medicine - was probably unparalleled in human history.
Because vitamins and the research behind his conclusions are the primary focus of his book, Pauling goes on to deplore the ignorance of most medical doctors and mainstream nutritionists (he calls the latter "old-fashioned" with good reason) of discoveries in biochemistry and molecular biology that cast a dramatically new light - to this day still not seen in most medical schools - on fundamental issues of human nutrition.
In particular, Pauling makes the case that the goal of nutrition ought to be to optimize health rather than merely to stave off disease, and that this goal cannot be achieved without supplementation of our diet with vitamins and other nutrients, no matter how good the diet may be in every other way. (He also makes the point, of course, that the other half of healthy living is regular exercise, without which we are planting one foot in the grave.)
GOOD HEALTH AS A FUNDAMENTAL RIGHT
Never one to shrink from controversy, Pauling attacks the government's inertia and often wrong-headed attitudes regarding nutrition, and he denounces the health-care profession (which he prefers to call the "sickness industry") for ignoring the new discoveries that have the potential to add years, if not decades, to our lives. He argues for the fundamental right of all people to try to enjoy the highest attainable standard of health and says, "It is a right that is open to you. All that you need to do is assert it by sensible behavior. What is more, thanks to the new science of nutrition, you can today multiply the benefits of healthy habits by taking, every day, the optimum amounts of the essential vitamins."
"Thanks to the
new science of
nutrition, you can
today multiply the
benefits of healthy
habits by taking,
every day, the
of the essential
vitamins." - Linus Pauling
Let us admit right here that there is no consensus on the "optimum amounts" of vitamins. Published recommendations range from the FDA's very small amounts - designed basically as threshold levels to ward off deficiency diseases - to some astonishingly large amounts touted by self-styled vitamin "experts" who cannot scientifically justify their claims. The true optima probably lie between these extremes, and serious, responsible experts constantly survey the scientific literature to see what the latest studies indicate in this regard. The objective is to maximize the potential benefits of supplementation while ensuring safety above all.
HOW TO GET THE ESSENTIAL VITAMINS,
AND GENE SUPPORT AS WELL
There are many multivitamin formulations on the market, of varying degrees of quality. Most also contain a variety of other substances, especially minerals. That's good, except that almost all of them contain iron, a mineral you should not take unless you are one of the relatively rare individuals with a genuine iron deficiency. For most people, supplementation with iron may do more harm than good, because iron promotes oxidation reactions that can cause cellular damage.
The gene-support supplement niacinamide is a close chemical relative of niacin (vitamin B3). Niacinamide has similar vitamin activity but is much easier to take - it doesn't cause the notorious niacin skin flushing, even at gene-support levels.
"Gene support"? What is that, you may well ask, and what does it have to do with vitamins? Gene support is nutritional supplementation that enhances the efficacy of any genetic mechanism whose effect is to optimize health or prolong life. Just such a mechanism has recently been discovered at MIT (see New Gene Supplements May Extend Your Life - April 2000, The Supercoiled Theory of Aging – May 2000, and Life Extension Ring – Jul. 2000). Called gene silencing, it acts to suppress the formation of DNA breakdown products that cause premature cell death, thus shortening lifespan. A molecule called nicotinamide adenine dinucleotide (NAD) plays a vital role in this DNA-protecting mechanism. The chemical precursor of NAD is nicotinamide, which is just another name for . . . niacinamide!
Thus, the familiar old vitamin niacin has just assumed new importance in the biochemical pantheon. Through niacinamide's role in gene silencing, it may help not only to keep us alive, as all vitamins do (vita means "life"), but to keep us alive longer.
WHAT ARE VITAMINS,
AND WHY DO WE NEED THEM?
Of the many organic compounds that are absolutely essential for good health, or even life itself, there are just a few - the vitamins - that our bodies cannot synthesize (or can synthesize only inadequately) from the foods we eat. We must therefore eat foods that already contain these vital molecules, or take supplements that contain them, or, preferably, both, because it's difficult to optimize our intake through food alone. Being organic (carbon-based) compounds, vitamins are the "flip side" of the essential mineral nutrients, which are inorganic (see Trace Minerals – Jul. 2000).
Vitamins are indispensable mainly because they serve as cofactors - or the precursor molecules to cofactors - to the enzymes that catalyze certain of the chemical reactions of life. By acting in concert with these enzymes, the cofactors (also called coenzymes) "switch them on" and enable them to perform their appointed tasks. Not all enzymes require a cofactor, but those that do are inert without them. Thus, a vitamin deficiency means a cofactor deficiency, which can severely impact some aspects of cell function. The result could be such diseases as scurvy (vitamin C deficiency), rickets (D), beriberi (thiamine), pellagra (niacin), or pernicious anemia (cyanocobalamin).
So, is avoiding such diseases equivalent to good health? Silly question. Good health is a state of optimal physical and mental well-being, not merely the absence of disease or infirmity. It is hard to know what the limits of "optimal" may be in this context, but what is no longer in question is that our rapidly expanding knowledge of nutritional science points to intelligently aggressive supplementation of our diet as the best means to achieve whatever that "optimal" may be (assuming, of course, that we have a good, healthy diet in the first place, accompanied by plenty of exercise).
Just to make things really interesting, by the way, Mother Nature has contrived to make some vitamins (and minerals) act as cofactors for each other. In other words, a given vitamin may work well only in the presence of certain other vitamins or minerals, in a kind of symphony of chemical interactions in which a missing "instrument" can spoil the harmony. Thus, there are sound scientific reasons for preferring, usually, to supplement with an expertly selected, broad-spectrum multivitamin/multimineral formulation, rather than with individual components.
WHY SHOULD WE SUPPLEMENT WITH VITAMINS?
For many years, some futurists have envisioned a brave new world of techno-nutrition in which we all sit down each day to a "meal" consisting only of vitamins, minerals, antioxidants, hormones, and other nutrients that together will satisfy our physiological needs. While it is not unlikely that we will eventually discover exactly what our bodies need for optimal functioning, the pleasures of life, including the taste of food, may not be as easily disposed of - nor would we want that. Who in their right mind would want to forego one of life's greatest pleasures, the enjoyment of delicious food?
The beauty of it is that we can "eat our cake
and have it too." We can enjoy delicious
food and make up for its deficiencies
through supplementation, as Pauling and
many other scientists recommend.
The beauty of it is that we can "eat our cake and have it too." We can enjoy delicious food and make up for its deficiencies through supplementation, as Pauling and many other scientists recommend. And we should do that, for at least two reasons:
1. Our diets - even good, healthy ones - are quite refined and unnatural compared to the kind of primitive diets (mostly raw foods) to which humans as a species became biochemically adapted over a few million years of evolution. Even when we are still young, we simply don't get enough of some nutrients, because some modern agricultural methods, such as adding synthetic fertilizers to poor, overfarmed soils, can yield foods that are attractive and tasty but nutrient-poor. And foods can lose vitamins, in particular, through lengthy storage, as well as through processing methods such as canning and cooking.
2. We are now - very suddenly on an evolutionary timescale - living two, three, even four times longer than our forebears did, and our aging bodies have needs for certain nutrients in much greater quantities than evolution ever "thought of" or provided for in the foods available to us, even if we eat them at their maximum nutrient levels.
In a nutshell, we are outfoxing evolution by living longer - much longer - than we are "supposed" to. We're expanding our horizons with the help of nutritional supplements, which represent the state of our knowledge of improving upon the value of food.
13 IS A LUCKY NUMBER
The 13 compounds that are now generally recognized as vitamins are A, C, D, E, K, and the eight B vitamins (often called the B complex). A few other compounds - notably choline, inositol, and lipoic acid - are sometimes called vitamins even though technically they are not, because our bodies can synthesize them in adequate (but not necessarily optimal) quantities. Many compounds that were at first thought to be vitamins turned out not to be vitamins after all, or they were duplicates of ones already discovered, which accounts for the gaps in the lettering system. Every missing letter (it has gotten as far as Y) represents one such molecular red herring. Furthermore, some of the vitamins are not single chemical compounds, but rather small groups of closely related compounds that have similar biological activities.
The first discovery of a vitamin (thiamine, which eventually became known as vitamin B1) was made by the Dutch physician Christiaan Eijkman in 1896, at a time when Louis Pasteur's germ theory of disease was yielding a flood of exciting new discoveries in medicine. In that climate, it was hard to believe that some diseases had nothing to do with germs but were caused simply by a dietary deficiency of some chemical compound. It took awhile, but eventually medical scientists came to accept this idea, based on a mounting body of irrefutable evidence, including the fact that it was impossible to catch the disease from an "infected" person, no matter how hard one tried (and some researchers did try hard, in some pretty disgusting ways - what a testament to the power of scientific curiosity!). Eijkman received the Nobel Prize for his discovery in 1929, shortly before his death.
An important property of all vitamins is their solubility in either water or fat, because that affects how they are absorbed and retained by the body. The fat-soluble vitamins - A, D, E, and K - are best taken with a fat-containing meal, which aids in their absorption by the gut. Our bodies tend to retain these vitamins longer (in fatty tissues) than the water-soluble vitamins (C and all eight of the Bs), which are more readily excreted in the urine when they are in excess.
With one exception, it makes absolutely no difference whether the vitamins we take are natural or synthetic - their properties are identical because their molecular structures are identical. The exception is vitamin E, a group of related molecules that have somewhat greater biological activity in the natural form than in the laboratory version, which is not an exact duplicate. The latter, however, is definitely effective, and much less expensive.
Vitamin A, or retinol, was not the first vitamin to be discovered, but it was the first to be officially named. We do not take retinol as such, because it is safer to take its precursors, especially a water-soluble compound called beta-carotene, an excess of which is eliminated in the urine. This tends to protect against a toxic overdose of the fat-soluble retinol, which can accumulate in our tissues. A deficiency of vitamin A adversely affects the skin, immune function, and eyesight (especially night vision), so ingesting it prevents these problems. In addition, vitamin A tends to protect our cells from the effects of many toxic chemicals, and it is a strong antioxidant that has been shown to help protect against certain cancers, especially prostate cancer, skin cancer, and lung cancer. It is also known to boost the immune system, thereby strengthening our resistance to infections.
Just about everyone knows about Linus Pauling's advocacy of taking megadoses of vitamin C, or ascorbic acid, to help prevent the common cold. But he did not stop there. He said, ". . . there is evidence, summarized in this book, that a large intake of vitamin C helps to control a great many diseases: not only the common cold and the flu, but also other viral and bacterial diseases, such as hepatitis, and also quite unrelated diseases, including schizophrenia, cardiovascular disease, and cancer."1 Controversy continues to swirl around his theories and the evidence he marshaled to support them, and it may be many years before the dust settles and a clear picture emerges. Meanwhile, it seems unwise to discount (as many in the medical community do) the ideas of this "megagenius," whose track record for ultimately being proved right on controversial issues is remarkable.
There is no controversy, in any case, about vitamin C's crucial role - as a chemical reactant, not merely a catalyst - in the body's synthesis of collagen, one of the most important and ubiquitous of all the structural proteins. In addition to preventing scurvy, a gruesome disease that has taken a huge toll of human life throughout history, vitamin C promotes tissue strength, wound healing, immune function, the health of our blood vessels and eyes, and more. It appears also to help with diabetes, allergies, asthma, and periodontal disease. And, as one of the most effective of all antioxidants (especially when taken together with vitamin E), it is indeed believed to offer protection against cancer.
Known as the "sunshine vitamin" because our skin manufactures it in response to sunlight, vitamin D (calciferol and cholecalciferol) helps us utilize calcium and phosphorus and thus promotes strong bones and teeth; it also protects against muscle weakness and may slow the progression of arthritis. When taken with calcium, especially in conjunction with regular exercise, it helps prevent osteoporosis. It is also believed to strengthen the immune system and possibly prevent some cancers.
One of the best-researched and most widely accepted nutritional supplements, vitamin E (a mixture of closely related compounds called tocopherols) is a powerful antioxidant (especially when taken together with vitamin C) that is believed to slow the aging process. It helps to protect cells and tissues - blood vessels in particular - from damage caused by free radicals generated by toxic chemicals, as well as damage caused by oxidized fats, which can lead to heart disease and cancer. It is now widely believed that vitamin E can indeed protect against heart attack and stroke, as well as colon and prostate cancers. It is also believed to help protect against degenerative diseases of the nervous system, such as Alzheimer's and Parkinson's.
Vitamin K consists of several compounds - the most common is phylloquinone - that act to promote blood clotting and thus prevent hemorrhaging. It is widely used to minimize bleeding during and after surgical operations. (One might think that it would also be useful in treating hemophilia, but, sadly, it isn't.) It is also helpful in developing normal bone structure and correcting osteoporosis.
THE B-COMPLEX VITAMINS
The eight B vitamins are grouped as such because, although they encompass a wide variety of molecular structures and perform many different functions, they are highly interdependent in their biological activity: most do not work well except in the presence of at least some of the others. Collectively, they facilitate the work of every cell in the body. Some help generate energy, and others help make DNA, RNA, proteins, and new cells.
For reasons too boring to discuss, the terminology of the B complex is inconsistent. Some have a B-number designation that is commonly used, some have one that is seldom used, and some have none. All of them, of course, have chemical names, so it doesn't really matter what the B-number, if any, is. Let's have a look at each one.
Thiamine (formerly called vitamin B1) functions in glucose metabolism, the production of brain neurotransmitters, and learning in children. It is helpful in treating disorders of the nervous system, certain skin conditions, and surgical wounds. It may also be helpful in preventing and slowing Alzheimer's disease.
Riboflavin (commonly called vitamin B2) is the "energy vitamin," facilitating the metabolic production of energy from foods, helping to produce thyroid hormones, and supporting healthy skin, hair, and nails. It also plays a role in the formation and maintenance of eye tissues, helps combat stress and fatigue, helps prevent migraine headaches, and may help to prevent colon cancer.
Niacin (formerly called vitamin B3) is produced in small quantities in the body by the amino acid tryptophan (with the help of vitamin B6). It functions in glucose metabolism and tends to suppress allergic reactions by acting as an antihistamine. In large therapeutic doses, it is well-known as a cholesterol-lowering agent, for which it is the most cost-effective and safe substance known. As we saw earlier, it is often used in the form of its chemical relative niacinamide (also called nicotinamide), which has similar vitamin activity.
Pantothenic acid (formerly called vitamin B5) is sometimes called the antistress vitamin because it supports the adrenal glands in producing certain stress hormones. It also helps cells metabolize fats and helps carbohydrates release energy. It is used to treat stress and fatigue after surgery, illness, or injury, to promote wound healing, and to combat heartburn.
Pyridoxine (commonly called vitamin B6) figures in so many life-supporting functions in metabolic reactions in our bodies - more than any other vitamin or mineral - that it is regarded as the most important of the B vitamins. It is necessary for the production of red blood cells, for protein metabolism, for energy production from food, and for maintaining a healthy nervous system, among others. In general, it can be viewed as the "feel-good" vitamin. It is helpful in preventing heart disease and alleviating the symptoms of PMS, asthma, and carpal tunnel syndrome.
Cyanocobalamin (also called cobalamin, and commonly called vitamin B12) was the last vitamin to be discovered, in 1948, and it is still somewhat of a mystery; its functions are not entirely understood. Its molecular structure is very complex and unusual, containing one cobalt atom (which is why cobalt is an essential trace element), and it is sometimes classed independently of the other B vitamins. It is essential for cell replication and plays a critical role in the production of DNA and RNA. It supports growth, appetite, and the formation of red blood cells and myelin sheaths (the insulating sheaths on nerve fibers). It may also be involved in the production of brain neurotransmitters, and it is used in the treatment of various mental disorders. Getting sufficient B12 is especially important as we grow older, as our ability to absorb it diminishes with age, and it appears to be important for proper immune function.
Folic acid (also called folacin, or folate when it is in the form of certain folic acid derivatives) is important in the formation of red blood cells (with the help of vitamin B12) and the metabolism and utilization of proteins and amino acids. It is vital for all processes involving cell division, and, like B12, it plays a critical role in the production of DNA and RNA. Dietary deficiencies of folic acid, which used to be very common, have been linked to an increased risk of neurological birth defects, so it is now found as a standard additive in cereal grains. Nonetheless, about 10% of the U.S. population is still believed to be deficient in this vitamin,2 and supplementing with it is important not just for women of childbearing age but also for older people, who may not get enough of it in their food. It should always be taken in conjunction with vitamin B12, because too much of one can mask a deficiency in the other.
Also of great importance is the role of supplemental folic acid (together with vitamins B6 and B12) in reducing the blood levels of the sulfur-containing amino acid homocysteine.3-5 Elevated levels of this amino acid, which become more prevalent with age, are strongly linked to an increased risk of vascular disease - cardiovascular disease in particular, but also peripheral vascular disease (including deep venous thrombosis) and cerebrovascular disease.6 There is also evidence that folic acid (again together with vitamins B6 and B12) may help decrease the risk of Alzheimer's disease and other neurodegenerative disorders.7
Biotin is one of the less important (though still essential) members of the B complex. Together with pantothenic acid, it helps produce many enzymes that trigger bodily functions, and it plays a special role in glucose utilization. It functions in the metabolism of fats and the synthesis of fatty acids and amino acids. It also helps to maintain healthy skin, nails, and hair.
WHAT DOES THE FUTURE HOLD?
Are there vitamins yet to be discovered? Probably. Although half a century has passed since the discovery of the last one, it would be presumptuous to think we have all the answers in the year 2000. Of the millions of different chemical compounds that occur in nature, many of which are found in our foods and beverages, some may be vitamins we still know nothing of. Who knows what further modes of life enhancement might become possible if we discover some of these vitamins and learn how to make the most of them.
Meanwhile, we can maximize the value of what we do know now about vitamins, minerals, and a number of other health-giving nutrients by supplementing daily with the broadest possible spectrum of nutritional benefits in a single product - including the new concept of gene support.
- Pauling L. How to Live Longer and Feel Better. W. H. Freeman and Co., San Francisco, 1986.
- Ames BN. Micronutrient deficiencies. A major cause of DNA damage. Ann NY Acad Sci 1999;889:87-106.
- Wilcken DE, Wilcken B. B vitamins and homocysteine in cardiovascular disease and aging. Ann NY Acad Sci 1998 Nov 20;854:361-70.
- Robinson K. Homocysteine, B vitamins, and risk of cardiovascular disease. Heart 2000 Feb;83(2):127-30.
- Pietrzik K, Bronstrup A. The role of homocysteine, folate and other B-vitamins in the development of atherosclerosis. Arch Latinoam Nutr 1997 Jun;47(2 Suppl 1):9-12.
- Seshadri N, Robinson K. Homocysteine, B vitamins, and coronary artery disease. Med Clin North Am 2000 Jan;84(1):215-37.
- Selhub J, Bagley LC, Miller J, Rosenberg IH. B vitamins, homocysteine, and neurocognitive function in the elderly. Am J Clin Nutr 2000 Feb;71(2):614S-620S.