Andrew Siegel, MD Blog #120
The human body needs nutrients and micronutrients—including vitamins and minerals—in balanced amounts in order to ensure optimal functioning. There seems to be a general misconception that with respect to vitamins and supplements, if some are good for you, than more are even better. However, excessive intake may either offer no additional health benefits or may even be harmful to our health. Too much can actually be dangerous—more is less. In light of the following words, caution needs to be applied to excessive intake of vitamins and supplements—less is more.
When I hit the big five-O (50 years old), I began taking a multivitamin and mineral supplement. The last vitamin I had taken was Chewable Chocks as a kid. I figured I was on the back nine of life and needed all the help I could get. Being the value-oriented consumer that I am, I headed over to Costco and picked up One-A-Day Men’s Health Formula that claimed to support prostate health, heart health and healthy blood pressure…all good! Each tablet contained Vitamins A, C, D, E, K, B1, B2, B3, B6, folic Acid, B12, biotin, calcium, pantothenic acid, iron, magnesium, zinc, selenium, copper, manganese, chromium, potassium and lycopene. It seemed like a lot of bang for the buck.
I continued taking the vitamins for a year or so, but did not notice any tangible benefit—I did not feel better, was not more energized, stronger, more potent in any way imaginable, did not get less colds, and my annual blood chemistries were unchanged. I came to the realization that I derived a lot more benefit from my morning caffeine infusion than from the daily vitamin.
Frankly, I had felt pretty good before starting the vitamin and mineral supplement and since I felt absolutely no different after using it, I stopped taking them and have never looked back. That stated, I eat a very healthy diet with an abundance of vegetables, fruits, legumes, whole grains, and lean sources of protein and am certain that my diet is not deficient in any vitamins or minerals.
At least one in three Americans use multivitamins and mineral supplements on a regular basis. There is no question that we need micronutrients in sufficient quantities to sustain our health. A nutritious and well-rounded diet should provide these essential micronutrients. The exceptions to this are the following: if your diet is poor; if you are pregnant; if you are a child; or if you are ill or have a compromised immune system due to certain medical conditions. Under such circumstances, supplementation is crucial. According to Susan Roberts (Tufts University Professor of Nutrition): “Multivitamins can fill in the gaps if you get too little of some vitamins and minerals from your food.” Specifically, there are five micronutrients that many of us do not get enough of: vitamin D, folic Acid, B12, iron and calcium.
It is best to obtain the necessary daily requirements of micronutrients from one’s diet. Vitamins and minerals that are sourced from a vegetable, fruit, etc. (nature) are advantageous because they contain important enzymes, peptides, and phyto-nutrients that are necessary to the proper/maximal utilization of the vitamins and minerals. Many studies have concluded that vitamins and minerals derived from diet are far superior to synthetic or formulated vitamin pills. Bioavailability is the degree of activity or amount of a substance that becomes available for activity in the target organ/tissue. In short, the bioavailability of the vitamins and minerals within a multivitamin is often significantly less than that of the vitamins and minerals in their natural form.
The other issues aside from bioavailability are that multivitamins vary greatly in quality, some have trivial amounts of some necessary micronutrients, and many have claims that are not clinically proven. Nobody even knows if the recommended quantities (the RDA or Recommended Dietary Allowances) are accurate or relevant. Another important point is that the fat-soluble vitamins D, E, A, and K are stored in the body, and excessive quantities can be problematic. On the other hand, excessive intake of the water-soluble vitamins B and C will result in your vitamin ending up in the urine, with your expensive vitamins enriching the diets of the crocodiles in the lake.
The therapeutic window is the “dose” range between what is effective and the amount that will give adverse effects. The ideal drug, nutrient, vitamin, supplement, etc., will have a “wide” therapeutic window. Coumadin is a commonly used drug to prevent blood from clotting. It has a very “narrow” therapeutic window, meaning that it easily can cause adverse effects. In the proper dosage, it prevents clotting in someone with atrial fibrillation (heart arrhythmia), venous thrombosis (clots) or in a person with a mechanical cardiac valve. Too much of a dose and the consequences can be lethal with death by impaired clotting with bleeding. In fact, this same drug in the form known as Warfarin can be bought in any home supply store and is used as rat poison, causing rodent death by bleeding. Understanding the concept of therapeutic window is important in terms of gaining insight into the potential adverse effects of overdosing on something that is healthy in the right doses.
Omega-3 fatty acids are widely popular as a means of lowering the risk of cardiovascular disease and cancer. Omega-3 fatty acids are available either by fish oil supplements or preferably by eating fish that are rich in these fatty acids including salmon, mackerel, etc. However, a recent report from Dr. Theodore Brasky (Journal of the National Cancer Institute) concluded that men with the highest intake of omega-3 fatty acids had a substantial increased risk of prostate cancer as compared to men with the lowest intake. The bottom line here is that it is difficult—but not impossible—to overdose on omega-3 fatty acids from the natural source (fish), but easy to do so with the supplements, so it is best to exercise moderation.
Other example of the potential benefits vs. risks of vitamin intake:
The SELECT (Selenium and Vitamin E Cancer Prevention Trial) seven-year study, was a study to determine if Vitamin E and selenium conferred a protective benefit regarding prostate cancer. The study concluded that men who took vitamin E supplements had elevated prostate cancer risk compared to those who took a placebo.
Niacin is a vitamin that is commonly used to decrease cardiovascular risk and works by lowering levels of LDL and raising levels of HDL. It has been shown that within a certain dose range, niacin decreases cardiovascular risk, but too much can cause severe liver damage as well as other adverse effects.
Magnesium is a mineral that is vital to numerous metabolic functions. In range, it is crucial to bodily functions, but excessive intake can cause cardiac arrhythmias, hypotension, diarrhea, etc.
Vitamin C (ascorbic acid) is an essential micronutrient that can cause the disease scurvy when deficient. Many people are very fond of taking mega-doses of vitamin C for a variety of reasons, one of which is the notion that they prevent colds. The problem is that since vitamin C is a water-soluble vitamin, any excess not needed by the body is excreted in the urine. High levels of vitamin C in the urine are one of the leading causes of kidney stones since the vitamin C is metabolized to oxalate—one of the ingredients of calcium oxalate stones, which is the most common kind of kidney stone.
The Bottom Line:
One of the keys to good nutrition is achieving balance—finding the happy medium between too little and too much consumption. If you eat a healthy, well-balanced diet that includes fruits, vegetables, lean protein, and whole grains, it is advisable not to waste your resources on multivitamin or mineral supplements. This does not apply to children, pregnant women, those suffering certain illnesses and those with a poor diet. If you are deficient in D, B12, folic acid, iron or calcium, it is of paramount importance to supplement your diet appropriately.
Andrew Siegel, M.D.
Author of Promiscuous Eating: Understanding and Ending Our Self-Destructive Relationship with Food: www.promiscuouseating.com
Available on Amazon in Kindle edition
Author of: Male Pelvic Fitness: Optimizing Sexual and Urinary Health, in press and will be available in e-book and paperback formats in the Autumn 2013.
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