RESEARCH NEWSLETTER SPRING/SUMMER 2014
LINUS PAULING INSTITUTE
MICRONUTRIENT RESEARCH FOR OPTIMUM HEALTH
The Case is Far from Closed for Vitamin and Mineral Supplements!
FROM THE NEWS DESK OF JEANNE HAMBLETON
UPDATED MAY 2014.
In their recent editorial in the journal Annals of Internal Medicine, “Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements,” the authors (Guallar, Stranges, Mulrow, Appel, and Miller III) conclude that “we believe that the case is closed—supplementing the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful.”
It appears that the authors themselves were not quite convinced of their conclusions because they added numerous qualifiers, such as “we believe” and “well-nourished adults,” and put “most” in parentheses.
While a well-balanced diet is the best way to get almost all of one’s essential nutrients, the reality is that Americans do not get enough of them every day through diet alone.
From the National Health and Nutrition Examination Survey (NHANES), we know that the large majority of the US population is not “well-nourished” and falls short of getting all of their vitamins and minerals from their diet in levels recommended by the Institute of Medicine’s Food and Nutrition Board.
For example, more than 93% of US adults 19 years and older do not meet dietary intake recommendations (called Estimated Average Requirement, or EAR) of vitamins D and E, 61% for magnesium, about 50% for vitamin A and calcium, and 43% for vitamin C.
Certain subpopulations, including older adults, African Americans, and the obese, have increased needs for some micronutrients. Other studies have shown that people who take a daily multivitamin/ mineral (MVM) supplement with the recommended doses of most vitamins and minerals can fill most of these nutritional gaps safely and at very low cost—a year’s supply of a high-quality MVM can be purchased for less than a nickel a day.
In contrast, only a very small, non-significant fraction (0.1%) of US adults exceeds the Tolerable Upper Intake Level (UL) from diet and supplements combined for vitamin E, putting Guallar et al.’s claim that “vitamin E … supplements increase mortality” in perspective. Contrary to the impression that the authors give in their editorial, the US population is inadequate in many vitamins and minerals, a result of the calorie-rich and nutrient-poor dietary pattern of Western populations, rather than over-consuming MVM and other dietary supplements.
Vitamins and nutritionally essential minerals maintain normal cell function, metabolism, growth, and development through their roles as essential cofactors in thousands of enzymatic reactions and other biological processes—their main biological function is not to prevent or treat chronic disease.
Nevertheless, the largest and longest randomized controlled trial (RCT) of MVM supplements conducted to date, the Physicians’ Health Study II (PHS II), found a significant 8% reduction in total and epithelial cell cancer incidence in male physicians and a 12% reduction in total cancer incidence, excluding prostate cancer.
The PHS II also found a significant 9% reduction in the incidence of total cataract. These findings of PHS II are consistent with those of several other RCTs and are even more impressive given the fact that the conventional RCT design is strongly biased against showing benefits of essential nutrients, in contrast to pharmaceutical drugs.
Unlike drug trials in which the control subjects have none of the drug in their bodies, subjects in vitamin trials will always have enough of the micronutrient present to prevent severe deficiency diseases—hence, there is no true placebo control group in such studies.
Furthermore, most published vitamin studies and trials have not measured the concentration of the vitamin in the subjects being tested but only assessed intake.
Many factors, including age, gender, disease, ethnicity, and genetic differences or polymorphisms, affect the concentrations of ingested micronutrients in the blood, organs, and tissues of humans. Without those measurements, it’s difficult to estimate the effect of supplemental micronutrients.
Taking a daily MVM supplement will not only help fill the known nutritional gaps in the average American diet, thereby assuring normal biological function and metabolism and supporting good health, but may also have the added benefit of reducing cancer and cataract risk—which no existing pharmaceutical drug can do.
The benefit-to-risk ratio also favors MVM supplementation, with plausible or demonstrated health benefits and little risk. To call “the case … closed” and label MVM supplements as useless, harmful, or wasteful is unscientific and does not serve public health.