Vitamin, a word for all seasons, a word deeply embedded in our brains since we were children. When I was a child, I remember my aunt insisting to my mother that she was sure the day would come when food would be a thing of the past, and vitamin tablets a thing of the future. We children were then taking cod liver oil every morning with our orange juice, in my mother’s hope that its vitamin A would make us strong and free of disease. “Those were the days,” said Archie Bunker. Now, here we are 50 years later and, although most of us still rely on food, more than one-half of us seem to be taking one type of vitamin or another. Many years have passed and many ideas have come and gone their way, but vitamins seem to be a constant–constantly growing in importance, that is.
Why are these nutrients so established in our minds, so impervious to change? What are these things? Are they, more or less, mostly the same? Are all vitamins essential so that they must be consumed virtually every day?
Undoubtedly, the vitamin story is a saga to be measured in decades, maybe in centuries, perhaps a story without end. A fad, it is not. These items have a rich past, a wealthy present (at least for the vitamin manufacturers), and a probable future. But where is this path leading us? We will, in future issues, unquestionably be commenting on new vitamin stories, ever emerging. To track the meaning of these stories, I suggest we pause to take stock of what are the fundamentals of this rather intense vitamin interest. Thus, this editorial sets forth some background that I plan to use in future newsletter articles.
Let’s start with a definition. The traditional definition of a vitamin goes like this, according to my medical dictionary: “a general term for a number of unrelated organic substances that occur in many foods in small amounts and that are necessary for the normal metabolic functioning of the body”. First, the word, “small” needs some emphasis. The daily amounts of vitamins recommended for consumption may be as low as 3 micrograms for vitamin B12–one tiny little ounce of this stuff is almost enough for 10 million people!, to 1.5 milligrams per day of riboflavin–one ounce would last one person about 50 years. The only relative exception is vitamin C: you need ‘tons’. Except for those megadose people who take an ounce about every 3 days, the daily amount recommended (60 milligrams–incidentally I think this is too low) would require about an ounce in a little over one year. Note: a word of caution. Just because these are tiny amounts (that’s why they are micro nutrients), we must not minimize their physiological importance. Don’t consume them for awhile, and your health is no more.
Now let’s move along to another point on these ‘pieces of gold’. The dictionary says, and the experts agree, that these micro nutrients are “necessary for the normal metabolic functioning of the body”. They are essential, meaning that the body must consume them already made; we cannot synthesize them from scratch. However, here’s where I personally take a side road because, with this definition, I cannot agree with science officialdom as to what they consider to be a vitamin. This is not a trivial difference of opinion because the health consequences of this misunderstanding already has caused serious misfortunes.
To get some idea of what is a vitamin, let us go back to the dawn of vitamin discovery, during the early part of this century, when there were certain nutrient deficiency diseases–beriberi, scurvy, pellagra–that begged for solution. The news from the world of science that extracts of certain foods could prevent, even cure these diseases generated widespread excitement, both within and beyond the scientific and medical research communities. The fact that vitamin C could cure scurvy, thiamin (vitamin B1) could cure beriberi, and niacin could cure pellagra sent out a message that science had surely discovered nutrients with awesome health promoting credentials (although we now know that these linkages are not so simple). The concept of vitamins was off to an auspicious beginning.
Also, in these early days, one of the first findings showed that some vitamins were soluble in fat, others in water. Named according to their discovery sequence, we had A, B (many kinds), C, D, E and K. The race was on to discover a vitamin for all sorts of ailments, both in humans and in experimental animals. Any kind of improvement in health produced experimentally by a bit of food was noted. Even an increased growth rate for the young was counted, generally meaning that the most rapid rate of growth also was the best. Although the above-listed vitamins were ordained to the official list, not all claims of new vitamins were accepted. Vitamins P, G, H, and some others have not made the cut.
These were heady days (1920s-1940s) for nutritional science, and they continued until eclipsed in the early 1950s by the remarkable discovery of the DNA structure by James Watson and Francis Crick. DNA was the stuff of genes and, since then, anything genetic has dominated the biomedical research agenda. In fact, the discovery of new vitamins was said by many to have come to a close.
Although research into the broader effects of diet has been relegated third class status in the biomedical research and clinical communities, research on individual vitamins, especially during the past couple of decades, has not. Unfortunately, this research has been, in my view, rather helter skelter.
No clear understanding has existed as to what is a vitamin and what is not. If a food chemical is ‘officially’ recognized as a vitamin, it enjoys the inside track in the research laboratory. Other substances, now known to have interesting health promoting activities, do not enjoy this same status. It’s as if we closed the book about 30 years ago on the official vitamin list. Never mind if some of these substances don’t belong on the list and others do. Being on the list, as in social orders, unfortunately makes a difference, whether or not there is merit. Inside members count, ostracized and un-initiated members don’t. This uncertainty, especially among researchers with little or no nutrition training, can make for big mistakes and lots of wasted funds.
To get a better appreciation of this problem, consider again two points, first, the part of the definition which says that a vitamin is an essential nutrient (it must be consumed on a fairly regular basis) and, second, which substances make the best known ‘official’ vitamin list. This list, that of the Food and Nutrition Board (FNB) of the National Academy of Sciences, includes A, thiamin, riboflavin, niacin, B6, folacin, B12, C, K, biotin, and pantothenic acid–and D by most other experts.
For openers, ‘vitamins’ A and D are not vitamins because they are not essential; they do not need to be consumed, as the definition requires. Vitamin A (retinol) is only a metabolite of the true vitamin, Ã›-carotene (not listed). Consumption of adequate amounts of Ã›-carotene provides for the body all the retinol that is needed. The body converts some of the Ã›-carotene to retinol and uses some of it for other purposes. It decides how much goes which way and, in the process maintains circulating levels of retinol within fairly narrow limits.
Vitamin D also is not essential because it can be synthesized by sunshine-exposed skin, then is transported to other parts of the body where it is used. Synthesis and traveling elsewhere makes it a hormone, not a vitamin. Again, the amounts of vitamin D and its metabolites which circulate are rather carefully controlled by the body according to its needs.
In both cases, consuming extra amounts of vitamins A and D runs the risk of violating the natural order of things by exceeding the upper limits of circulation desired by the body. Is it any wonder, then, that these are the two vitamins with the greatest number of reports of toxicity? Did you know, for example, that vitamin A at higher levels of intake, actually can increase, not decrease, cancer risk? Also, did you know that these are the only two vitamins only found in flesh foods (a different kind of vitamin D may be present in some plants)? Historically, it now is clear that they initially were labeled as vitamins at a time when consumption of generous amounts of animal foods was considered advisable.
I do not mean to say that consuming vitamins A and D, as supplements or as added to foods, is never useful, but I do mean to say that the benefits to be derived, if any, are observed, in theory, only when Ã›-carotene intake (from colored plant matter) and sunshine exposure are inadequate. Both of these presumed ‘vitamins’ are downstream from their major sources and it is these sources which we need to emphasize.
The tragedy of misunderstanding this issue is that probably close to a billion dollars, for example, have been spent in the past couple of decades to show that vitamin A could prevent cancer at various sites. The results have been very disappointing, even hazardous to some volunteers. If only some attention had originally been given to the idea that shoving extra vitamin A into an already regulated pool mostly was a violation of the natural order of things, we would be in far less trouble.
The second problem with the conventional vitamin definition is that it is too restrictive. It omits the thousands of plant chemicals (phytochemicals) now being shown to have useful activities toward the prevention of chronic degenerative diseases. Of course, these activities must be developed only within the context of whole foods, again where the natural order does its own thing on its own time, and under its own conditions.
In both cases, the unnecessary inclusion of vitamins A and D in most official vitamin lists and the exclusion of the plant chemicals reflect the serious bias favoring the consumption of animal-based foods in years past, and still too often in years present (the animal based vitamins are incorrectly on the list while the plant based would-be vitamins are off. These orthodox views of vitamin nutrition and vitamin definitions have undermined research on the health-promoting value of plant based foods. I suggest that we re-design our views on vitamins, and simply say that those goodies which promote our health, in so many ways, are abundantly present in plant foods. Consuming either animal based foods or vitamin supplements is not necessary to achieve ‘vitamin’ health. At best, they can only fill some gaps, when we choose not to do the right thing.
Copyright 2022 Center for Nutrition Studies. All rights reserved.
100% online, learn at your own pace
A trusted credential from eCornell
Personalized feedback from our team of instructors
20,000+ students and counting