Overview: Conventional wisdom previously dictated that a person who eats a varied diet does not need dietary supplements. Concern about wasting valuable resources on unneeded supplements and possible toxic reactions led many health care professionals to advise against anything more than a basic vitamin and mineral supplement that contained only the basic RDA recommendations.
Recent data about the role of vitamins and minerals, not just to prevent classic deficiency states, but to alter the course of chronic diseases, prevent cancer and heart disease, and/or to optimize the functioning of a healthy individual, have continued to raise the question of whether a higher dose supplement might not be beneficial.
This is a hotly debated area of medicine today. Practicing physicians must make decisions about what to recommend everyday based on incomplete research information. Each clinician must make their own choice based on their evaluation of the literature. Thus, whether we are only trying to answer our patients’ questions, or trying to formally recommend appropriate supplements to our patients, we must not only answer the question, “What is the level of intake…judged to be adequate to meet the known nutrient need of practically all healthy persons,” the question answered by the National Research Council in determining the RDA’s, but we must delve further into determining the level of intake judged to be optimal to meet the nutrient needs of those for whom we care.
To answer this question in future posts, we will address four issues for each vitamin and mineral reviewed: 1. What are the known sources and biochemical function(s) in the human body of each vitamin or mineral? 2. What are the possible safety concerns and the safety ranges for the vitamin or mineral? 3. What are the current recommended daily allowances? and 4. What is the published medical literature tell us about each vitamin and mineral? At the conclusion of the review recommendations will be made for an “evidence-based supplement” for our readers.
Who Should Take a Supplement? The decision whether to recommend a supplement and at what dose is more complex than it may initially appear. Several variables must be considered in order to make an educated guess at what will best benefit an individual. These include the average dietary intake of the individual with regard to vitamins and minerals, their age and gender, any metabolic or endocrine function that increases their needs, any medical illnesses they have that may impact their ability to absorb, utilize, or increase their daily needs, and the effect of medications the individual may be taking on vitamin and mineral metabolism in the body.
The Average Daily Intake of Vitamins and Minerals: The results of the National Health and Nutrition Evaluation and Survey (NHANES 2000-2006) data was released several years ago. The picture confirmed from NHANES III is that the average American diet contains way too much fat, particularly saturated fat, too much sugar, and too much protein. The trend is toward processed and refined foods and away from fresh and whole grain products. The average American is much more likely to grab a high carbohydrate and saturated fat snack for breakfast than to eat fruits, vegetables, or lean protein as they head out the door in the morning. Fast food consisting of high fat meat on white bread with deep fried skinless potato’s (French fries) at lunch, and a dinner based around meat containing 50 to 60% of its calories from fat combined with starch for dinner. The consequences of this dietary pattern is very evident.
The macronutrient content (carbohydrate, protein, and fat) is leading to an overconsumption of calories, thus to the recent trends in overweight and obese individuals now at over 63.1% of our population and still climbing (Gallup-Healthways Well Being Index 2009.) The health consequences for this are also becoming evident with epidemics of diabetes, hypertension, and hyperlipidemias. Their natural endpoints, heart attacks and strokes, are the number one and three killers, respectively, of Americans.
A less well appreciated aspect of these trends are their effect on vitamins and mineral consumption. The best source of vitamins and minerals are fruits and vegetables. Unfortunately, this processed and fast food revolution we currently are experiencing, has led to an all time low in the consumption of these important complex carbohydrates. It is now estimated that the average American takes in only one helping of fruits or vegetables per day – far below the five to seven helpings recommended by the Food and Drug Administration.
This is particularly disturbing in children where a recent publication reported: ” When whole grain products like whole grain breads, pasta, and brown or wild rice are added to the fruits and vegetables additional important vitamins and minerals as well as fiber intake is appreciated. This too, has been declining dramatically as refined flour for bread and pasta, and white rice are the predominant forms of carbohydrate replacing the older staples of whole grain products. The process of refining the flour removes the valuable vitamins and minerals. To some degree, this problem is being addressed with ‘enrichment’ of the flour, the process of reintroducing the micronutrients on a selective basis to the flour. A good example of this is the current movement toward supplementing products with folate to decrease the fetal malformations that can result from a folate deficiency. Thus, we are attempting to put back into our food supply the nutrients we have removed by over processing in the first place.”
High fat foods lead to their own set of challenges. In order to break down and control the damage that excess intake of polyunsaturated fatty acids (PUFA’s) can lead to, the body must use vitamin E. Thus, the intake of PUFA’s leads to an increase in the need of vitamin E either in the diet or via supplements.
The result of these trends is that the average American is becoming obese at the same time they are becoming malnourished from a vitamin and mineral standpoint. How this applies to an individual will depend on how active they are in managing their diet to insure they get enough fruits, vegetables, and whole grain products. As a general rule, the harder they work at this, the less they need a supplement. The clear exceptions to this are vitamin E and D, which appears to be beneficial in amounts greater than 40 IU and 400 IU respectively, the amount you can get from a good diet. Thus, even in the best controlled diet there may be a place for vitamin E and D supplementation.
The Effect of Age and Gender on Vitamin and Mineral Needs: As we look at our lifecycle we see very different needs for vitamins and minerals. As a young child, we are growing and very active. Thus, our need for vitamins and minerals are increased. A good example of this is the need for calcium and vitamin D in girls from birth to the mid- twenties when the majority of their bone growth will occur. If their diet is high in vitamin D and calcium, they will end up with a better bone mass going into skeletal maturity, and thus decrease the chance of osteoporosis later in life. Thus, the early years of life are a time when a rich, varied diet and an appropriate vitamin and mineral supplement can be very beneficial.
Another time period in which proper intake is vital occurs in the older age groups. Age related changes in the gastrointestinal tract decrease the ability to absorb vitamins and minerals. Thus, a complete and regular diet and/or supplementation becomes more important. A good example of this is vitamin B12 absorption which decreases in many over 65 years of age. This change may be gradual which leads to difficulty in recognition of this condition. Thus, again with older individuals, recognition of their increased need and the possibility of a decreased dietary intake of high quality food may lead to the recommendation for supplementation of some kind.
Metabolic and Endocrine Functions that Alter the Need for Nutrient Intake: The most obvious of normal processes that increases the need for a careful diet and/or supplements is the menstral cycle in women. The loss of iron in this process has led some to estimate that up to a third of American women suffer from iron deficiency with its resulting fatigue, poor exercise tolerance, and increased susceptibility to infection. However it has been shown that supplementing iron in men who are not deficient can increase the risk of MI.
Medical Illnesses: When a patient presents with an illness, the healthcare provider is focused on the best way to address and cure the patient. The benefit of diet and supplements is often overlooked, usually as a result of attention to other medical challenges, but may be very important in curing the patient.
Chronic diseases like diabetes may alter the need for certain vitamins and minerals. When the bodies machinery is limited by specific defects in functioning or increased stress on the system, the rate that different vitamins and minerals are needed may change. Diabetes illustrates this nicely in two ways. First, we know that if an individual is deficient in chromium, their ability to appropriately utilize glucose is hindered. Thus, in a diabetic it may be wise to insure that the patient has enough chromium in the form of whole grains, vegetable oils, nuts, and so forth; or a supplement of 200 μgms/day should meet any increased need. A second example is the increased oxidative stress a diabetic experiences. The most important way to control this is with good glucose control. However, it also would appear reasonable to make sure that the patient gets plenty of vitamin C, E, alpha lipoic acid, and other antioxidants from their diet and/or a supplement. This is especially evident given the high (80%) prevalence of cardiovascular deaths and severe peripheral neuropathies in this population.
Acute conditions may also lead to an increased need for vitamins and minerals. Burns are a classic example of a condition that requires significant increases in the bodies metabolic functioning in order to repair the damage. Other conditions that increase the bodies need for specific nutrients include acute infections, surgery, chemotherapy, and gastrointestinal disorders that alter absorption. In each case, the increased needs and the alteration in intake must be evaluated and specific recommendations about how much and what nutrients should be increased through the diet and/or a supplement can be added.
“Medications”: The reason I put this title in quotation marks is that we have entered a new world with the “nutriceutical revolution.” An example of this is the new foods that are available to combat specific illnesses. New margarines are available to help a person control their cholesterol. Unfortunately, these new spreads also appear to absorb some of the fat soluble vitamins, and thus, could help one problem while aggravating another. This is also the case with cholestyramine or colestipol which is another agent; this time a prescription drug that is used to treat high cholesterol.
Even supplementing with vitamins may lead to an increase in the needs of your body in other areas. A good example of this is with the new move to aggressively supplement individuals with folate. An increase in folate consumption leads to an increase in the bodies demands for vitamin B12. In individuals not able to absorb vitamin B12 well, this can result in a neurologic syndrome that looks like dementia if they do not receive additional vitamin B12, either orally or parenterally.
Certain medication can lead to vitamin deficiencies. This is the case with isoniazide or dilantin, which will lead to a deficiency in vitamin B6 if taken chronically. Taking tricyclic antidepressants, doxorubicin, Thorazine and/or Prolixin, or a tetracycline-family antibiotic may lead to an increase in the amount of vitamin B2 (riboflavin) you may need.
This also works the other way, where a vitamin undermines the effectiveness of a medication. For example, vitamin K will interact with coumadin and prevent the very important blood thinning properties.
Conclusion: Thus, the question of whether to take a simple vitamin and/or mineral supplement is not as simple as it might seem. The first question that must be answered is where is the individual starting from nutritionally and from a general health standpoint? What is the level of physiologic stress they will experience due to increased activity or illness? Where is their ability to absorb and utilize the vitamins and minerals, and the other medications they will be exposed to? All these issues must be considered. It would be ideal if a research agenda to explore each of these situations could direct a health care provider with their recommendations. However, with all of these complexities, it is not realistic to expect every question to be answered with carefully controlled studies. Thus, we must look at the research and at those for whom we care and make the most informed decision possible. It is with this goal in mind that future posts will be written.