Editor’s note: Wellness Word is an informational column which is not meant to replace a health care professional’s diagnosis, treatment or medication.
The Vitamin-Mineral Supplement Paradox
For more than half a century, the conventional wisdom has been that vitamins and minerals are essential nutrients for maintaining a healthy body. This belief was reinforced when, in 2002, the Journal of the American Medical Association (JAMA) published an article that said “There is overwhelming evidence that vitamin deficiencies are associated with the chronic disease process and the overall condition of one’s health.” The concept that our diets can be deficient in necessary micronutrients encouraged many health practitioners to recommend a daily multivitamin-mineral (MVM) supplement. The premise was that a daily MVM would fill in any nutritional gaps. This was touted as “cheap health insurance” and a good way to improve and maintain health.
Older Americans are significant users of supplements – about 40% of women and 52% of men. An estimated 150 to 180 million Americans take them to make up for any dietary deficiencies and to improve our overall health, despite the lack of substantial studies proving their effectiveness. Paradoxically, despite this lack, the use of dietary supplements, which are mostly self-prescribed, with little or no input from informed health practitioners, continues to increase. We spend more than $30 billion a year on about 85,000 different supplements, the bulk of which are MVMs.
When our cells change oxygen and food into energy, oxygen molecules with an odd number of electrons are produced. We call these by-products of our normal metabolism free radicals. Free radicals are highly reactive molecules that attack crucial parts of our cells. They are found everywhere in the external environment (pollution, pesticides, radiation), but a principal source of exposure is internal.
Dr. Denham Harman, a researcher for Shell Oil, in his 1956 paper suggested that an inefficient response to increased free radical production contributed to the development of most of the chronic diseases of aging. He proposed that feeding cells with antioxidants would mop up excess free radicals, thereby reducing the damage and extending life.
Our body has a built-in antioxidant defense system that depends on a constant supply of antioxidants from our diet (fruits and vegetables) to function optimally. This generally keeps the level of free radicals and antioxidants in balance. The efficiency of our energy production declines with advancing age causing an increase in free radical production, thereby tipping the balance in favor of the latter.
Free radicals, however, also serve a number of vitally important functions, like signaling the immune system to defend against invading bacteria. The immune system uses free radicals to destroy these organisms. The benefit of moderate exercise is due to the generation of small amounts of useful free radicals. Blocking naturally-produced free radicals with high dose synthetic vitamins can undermine any benefits.
The 2006 National Institutes of Health (NIH) State-of-the-Science Conference concluded that the evidence that MVMs prevent heart disease or cancer is insufficient. The American Heart Foundation adds that supplemental vitamins A, C, and E should not be used to control blood pressure or lower blood cholesterol. The National Cancer Institute says a daily MVM offers no proven health protection against cancer. In fact, there is some evidence that some antioxidant supplements may actually increase risk of certain cancers.
A 2013 article in the Annals of Internal Medicine entitled “Enough is Enough: Stop Wasting Money on Vitamin and Mineral Supplements” states that “supplementing the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful.”
An anti-supplement tsunami was unleashed when a 2007 report in JAMA evaluated 68 earlier studies involving almost a quarter of a million participants. Only the data from those studies that met the strictest statistical criteria were considered. The conclusion reached was that treatment with beta carotene, vitamin A and vitamin C to prevent disease may actually increase mortality.
A NIH publication (2011) reported that long term use of beta-carotene supplementation significantly increased lung cancer incidence, particularly among heavy smokers. The US Preventive Task Force recommended against using beta-carotene supplements for prevention of cancer or heart disease because of possible adverse outcomes. Beta-carotene from food does not appear to have this effect.
The 2010 Physicians Health Study II (involving male physicians over 50 yr. old), concluded that multivitamins and individual supplements of beta carotene as well as vitamins C or E found no statistically-significant difference in the rates of heart attack and stroke. Those who took the multivitamin had an 8% lower risk of cancer. However, it did not reduce the risk of prostate cancer. A 2011 JAMA study of over 35,000 men found that dietary supplementation with 400 IU of vitamin E in healthy men significantly increased risk of prostate cancer.
Calcium and vitamin D supplementation is routinely recommended by health practitioners as a key strategy to prevent osteoporosis, but the accumulating evidence that supplemental calcium may be associated with increased risk of heart attack has created a problem. A report in the June 2012 issue of Heart by German and Swedish scientists followed almost 24,000 adults for an average of 11 years. They found that regular users of calcium supplements had a significant increase in their heart attack rate compared to those who did not take them. Importantly, they also found that there was a lower risk of heart attack among adults with a moderately high intake of calcium from food.
They proposed that the adverse affect of calcium supplements may be due to the acute increase in serum calcium, an effect observed after ingesting calcium supplements but not after eating calcium rich foods. Based on the results of this study, the authors stated “calcium supplements should be taken with caution”. Still, a 2012 report in the Annals of Pharmacotherapy as well the National Osteoporosis Foundation position is that there is no cause to change the routine practice of recommending calcium supplements containing vitamin D in patients who have or at risk of osteoporosis.
Folate deficiency had once been a problem, causing birth defects in the newborn. A report from the Centers for Disease Control and Prevention found that folate deficiency is now nearly non-existent, below 1%, primarily due to the fortification of most grain products. The Institute of Medicine recommends 1000 micrograms of folic acid daily as the highest safe level for adults. A diet high in whole grains and folate rich vegetables in combination with a MVM may easily exceed the upper safety level in some individuals. There is some concern that excess folate may raise the risk of promoting previously undetected cancers. Moreover, excess folate can mask a vitamin B-12 deficiency, not uncommon in the elderly. An untreated B-12 deficiency can seriously compromise health.
It seems that most synthetic vitamins aren’t living up to their reputation as good dietary additions. This has created a dilemma for the primary consumers of MVMs, health conscious individuals, most of whom are well-educated and follow a healthy lifestyle. There are researchers who believe that the amounts of any particular vitamin should be “individualized” in order to derive any of the supposed benefits. The recommended daily allowance for a particular nutrient should be adjusted (higher or lower) because of multiple factors, including age, life-stage, gender, overall health status, degree of physical activity and compatibility with any medications.
Although dietary supplements, like drugs, have risks and side-effects, they are regulated by the US Food and Drug Administration (FDA) as foods. Because of this, the FDA has no jurisdiction over unproven claims. Advertisers have few restrictions on what they can say to promote a particular product. It is the supplement industry that is solely responsible for guaranteeing that their products meet safety standards prior to marketing. A product is taken off the market only after it has proved to be unsafe or the labeling to be misleading.
The increasing scientific evidence that most supplements offer no proven health benefits over a well-balanced diet has been a game changer for health practitioners. Many now do not advise supplements unless there is a clear-cut deficiency or a specific health condition. Even spokespersons for the supplement industry agree that one should start with a good diet for optimal health. The 2007 NIH-AARP Diet and Health Study provided strong evidence that the foods in the Mediterranean diet, which has an abundance of fresh fruits and vegetables, reduced the risk of death from all causes, including heart disease. It is the combination of naturally occurring vitamins, minerals, phytonutrients and fiber from whole foods, as well as fortified foods, that provide essential health benefits.
The take-home message from the NIH is that most older people don’t need a complete multivitamin supplement. Regardless, MVMs are routinely recommended by recognized health specialists who believe the benefits outweigh any purported risks. The suggestion is that elders already taking or considering taking any supplements should consult with a health practitioner to develop a personalized regimen. They must be certain the supplements will not interact with any prescribed medications or worsen any pre-exisiting conditions.
Jules M. Elias, PhD, resides in Portland and is Emeritus Professor of Clinical Health Sciences, Health Sciences Center, SUNY at Stony Brook N.Y. He can be reached at firstname.lastname@example.org