Over the past several years there have been subtle indications 
that chronic high-dose supplement intake is associated with ill health. About 15 years ago, a study assessed whether the supplemental intake of vitamin A and beta-carotene (an antioxidant) could help in the treatment of lung cancer, but the study had to be stopped when the researchers determined that those taking the supplements developed a higher mortality risk. (N Engl J Med 1996; 334: 1150-5) A more recent study assessing whether supplemental vitamin E could reduce lower respiratory tract infections in nursing home residents found that it had no benefit. (JAMA 2004; 292(7): 828-36) A meta-analysis to determine if so-called ‘immune-boosting’ supplements (including anti-oxidant vitamins and zinc) could prevent exercise-induced immune impairment found no evidence that they helped. (J Sports Sci 2004; 22:115-125) In fact, it was determined that athletes taking vitamin E supplements for 1 to 2 months prior to a competitive triathlon race had more lipid peroxidation and tissue inflammation than those not taking it. This is precisely the opposite of what most people would have expected to find. (Med Sci Sports Exerc 2004; 36(8):1328-1335)
Several studies have suggested that overtaking certain anti-oxidant supplements may inhibit the body’s normal system (called apoptosis) for ‘killing’ bad (i.e., cancerous) cells. The apoptosis system uses an oxidative killing system that can be inhibited with excess intake of antioxidants. Consider that men who took 400 I.U. of vitamin E daily (a common supplement dosage for this antioxidant) were 17 times more likely to develop prostate cancer over the 7 years they were followed. (JAMA 2009; 301(1): 39-51)
Part of the problem is that commonly available supplements have huge doses of nutrients associated with them, and these are often 500 times greater than the daily-recommended intake. It is no longer good thinking to imagine that all these excess nutrients are passively excreted if you don’t need them.
As these studies show, taking nutrient supplements that do not target an assessed nutrient deficiency may be dangerous for your health. However, since the body tries to adapt to whatever you do, the ideal strategy for weaning yourself off unneeded supplements would be go off them slowly. Try cutting the dose and frequency of intake by half every week until you eliminate them altogether. Ultimately, it is important to remember that food is the basic unit of measure in nutrition, so try to eat a wide variety of foods that emphasize vegetables, whole grains, and fresh fruits so that your tissues are optimally exposed to the vitamins and minerals they need. If you really want to know whether the foods you eat deliver the vitamins and minerals you need to stay healthy, try doing a nutrient intake analysis through NutriTiming, which is accessible through your Titus PEAK performance tracking application.
Recent features that address the risk of supplementation:
- Supplements Offer Risks, Little Benefit, Study Says, Wall Street Journal. October 11, 2011
- Vitamin Supplements Associated With Increased Risk for Death, Medscape News. October 10, 2011
- Studies Suggest Case for Dietary Supplements is Collapsing, Fox News. October 26, 2011
- Vitamin safety worries: ‘Not as harmless’ as we thought, Chicago Sun Times. October 13, 2011